Circuit Breaker 22AIC...

[Fred Bloggs]

On Monday, September 25, 2023 at 12:05:38 PM UTC-4, Eddy Lee wrote:

On Monday, September 25, 2023 at 9:00:25 AM UTC-7, Fred Bloggs wrote:
On Sunday, September 24, 2023 at 11:20:37 PM UTC-4, Eddy Lee wrote:
On Sunday, September 24, 2023 at 7:50:01 PM UTC-7, Fred Bloggs wrote:
On Sunday, September 24, 2023 at 6:24:38 PM UTC-4, Eddy Lee wrote:

The have two version of 20A breaker, 10AIC and 22AIC. I guess I don\'t really know what they mean. It\'s plug-in microwave and fridge on the same circuit.
No way will the fridge/ microwave combo trip a 20A breaker. I\'m guessing you\'re misreading \'AIC\' for AFC, arc fault circuit interrupter, and that is something that just may trip on the fridge compressor start-up surge or the microwave start-up surge. The microwave by far draws the most current. It must move the AFCI trip threshold into a new regime that makes it trip if the fridge happens to come on while it\'s running. California electric code requires all kitchen branch circuits have AFCI protection, so no getting around that.
It\'s 22KAIC, but they usually omit the K

https://www.breakerbroker.com/ge-thef113020-used-277v-ge-thef113020-20a-277v-1p-used/

Nothing on the circuit that add up to 20A.
AFCI doesn\'t trip on current alone. It has some kind of analyzer circuit looking for transients on the wire characteristic of arc-over. When it detects what it thinks is a hazard, it trips, and that can happen at far less current than the current rating on its label. It also works like a conventional breaker as regards over-current.

It\'s sounding like the uwave/ fridge is a bad combination. You\'ll need to separate them. Before you go to that trouble, check to see the microwave alone doesn\'t trip the AFCI. Some appliances are problematic and will do that. A fix for that will be inconvenient.
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.

I encountered one oversensitive AFCI that would reliably trip if I just put my \'near\' the insulated wire in a fixture. I couldn\'t believe it but there was no doubt that\'s what it was doing.

 

[John Smiht]

On Monday, September 25, 2023 at 11:19:04 AM UTC-5, Fred Bloggs wrote:

On Monday, September 25, 2023 at 12:05:38 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 9:00:25 AM UTC-7, Fred Bloggs wrote:
On Sunday, September 24, 2023 at 11:20:37 PM UTC-4, Eddy Lee wrote:
On Sunday, September 24, 2023 at 7:50:01 PM UTC-7, Fred Bloggs wrote:
On Sunday, September 24, 2023 at 6:24:38 PM UTC-4, Eddy Lee wrote:

The have two version of 20A breaker, 10AIC and 22AIC. I guess I don\'t really know what they mean. It\'s plug-in microwave and fridge on the same circuit.
No way will the fridge/ microwave combo trip a 20A breaker. I\'m guessing you\'re misreading \'AIC\' for AFC, arc fault circuit interrupter, and that is something that just may trip on the fridge compressor start-up surge or the microwave start-up surge. The microwave by far draws the most current. It must move the AFCI trip threshold into a new regime that makes it trip if the fridge happens to come on while it\'s running. California electric code requires all kitchen branch circuits have AFCI protection, so no getting around that.
It\'s 22KAIC, but they usually omit the K

https://www.breakerbroker.com/ge-thef113020-used-277v-ge-thef113020-20a-277v-1p-used/

Nothing on the circuit that add up to 20A.
AFCI doesn\'t trip on current alone. It has some kind of analyzer circuit looking for transients on the wire characteristic of arc-over. When it detects what it thinks is a hazard, it trips, and that can happen at far less current than the current rating on its label. It also works like a conventional breaker as regards over-current.

It\'s sounding like the uwave/ fridge is a bad combination. You\'ll need to separate them. Before you go to that trouble, check to see the microwave alone doesn\'t trip the AFCI. Some appliances are problematic and will do that. A fix for that will be inconvenient.
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
I encountered one oversensitive AFCI that would reliably trip if I just put my \'near\' the insulated wire in a fixture. I couldn\'t believe it but there was no doubt that\'s what it was doing.

What is your \'near\'?

 

[Fred Bloggs]

On Monday, September 25, 2023 at 1:02:33 PM UTC-4, John Smiht wrote:

On Monday, September 25, 2023 at 11:19:04 AM UTC-5, Fred Bloggs wrote:
On Monday, September 25, 2023 at 12:05:38 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 9:00:25 AM UTC-7, Fred Bloggs wrote:
On Sunday, September 24, 2023 at 11:20:37 PM UTC-4, Eddy Lee wrote:
On Sunday, September 24, 2023 at 7:50:01 PM UTC-7, Fred Bloggs wrote:
On Sunday, September 24, 2023 at 6:24:38 PM UTC-4, Eddy Lee wrote:

The have two version of 20A breaker, 10AIC and 22AIC. I guess I don\'t really know what they mean. It\'s plug-in microwave and fridge on the same circuit.
No way will the fridge/ microwave combo trip a 20A breaker. I\'m guessing you\'re misreading \'AIC\' for AFC, arc fault circuit interrupter, and that is something that just may trip on the fridge compressor start-up surge or the microwave start-up surge. The microwave by far draws the most current. It must move the AFCI trip threshold into a new regime that makes it trip if the fridge happens to come on while it\'s running. California electric code requires all kitchen branch circuits have AFCI protection, so no getting around that.
It\'s 22KAIC, but they usually omit the K

https://www.breakerbroker.com/ge-thef113020-used-277v-ge-thef113020-20a-277v-1p-used/

Nothing on the circuit that add up to 20A.
AFCI doesn\'t trip on current alone. It has some kind of analyzer circuit looking for transients on the wire characteristic of arc-over. When it detects what it thinks is a hazard, it trips, and that can happen at far less current than the current rating on its label. It also works like a conventional breaker as regards over-current.

It\'s sounding like the uwave/ fridge is a bad combination. You\'ll need to separate them. Before you go to that trouble, check to see the microwave alone doesn\'t trip the AFCI. Some appliances are problematic and will do that. A fix for that will be inconvenient.
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
I encountered one oversensitive AFCI that would reliably trip if I just put my \'near\' the insulated wire in a fixture. I couldn\'t believe it but there was no doubt that\'s what it was doing.
What is your \'near\'?

Hand- wire nutting live wires to a ceiling light fixture with all the bulbs removed. AFCI tripped when I just touched a single wire, by the insulation of course.

 

[Don Y]

On 9/25/2023 9:04 AM, Fred Bloggs wrote:

On Monday, September 25, 2023 at 6:32:24 AM UTC-4, Don Y wrote:
On 9/24/2023 6:35 PM, Eddy Lee wrote:
On Sunday, September 24, 2023 at 5:43:06 PM UTC-7, Don Y wrote:
On 9/24/2023 4:08 PM, Eddy Lee wrote:
There are 4 breakers and 3 empty slots in the panel. I guess they really cut corners in this apartment. I might add some more breakers, but making holes for wires is the problem.
The fact that it would likely get you tossed out of the apartment
might factor into your decision (as it would put the owner\'s
liability front and center should some OTHER tenant suffer harm
or loss as a result of your actions).

Note that you also need to know how the panel is *fed*
(what ampacity circuit).

And, running cable is not likely to be easy in \"old works\".

Note that you won\'t be able to claim \"the wires were there\"
as the wire will have a date code imprinted on it
every few feet (unless you happen to have some old
wire on hand that predates your occupancy).

Seems considerably easier to just change your usage patterns.

I\'ll try not to use the electric stove and microwave at the same time, although they are on separate breakers. I\'d have to unplug the fridge to use the microwave.
The Code requires dedicated circuits for these major appliances
precisely to eliminate the nuisances that arise from two or more
of them being used concurrently. When people are \"plagued\" by
nuisance trips, they look for ways to BYPASS those safety devices
(that are simply doing their jobs; the Code frowns on this sort
of behavior and tries to anticipate it).

[Ever notice how many/few receptacles are on each branch circuit?
Do you really think they expect you to plug vacuum cleaners
into ALL of them??]

Note that there is an EXPLICIT exception that *allows* a fridge
(which is classified as a major appliance and thus requires a
dedicated branch circuit) to be placed on one of the \"small
appliance\" counter circuits -- but \"best practices\" (i.e., anyone
who isn\'t pinching pennies) will always have the fridge on a
15-20A dedicated circuit (of course, an apartment application
could be rationalized as not needing to support a big fridge).

Neighbor complained to me that his fridge would \"go off\" whenever
he used his microwave oven. His home was wired with the fridge
on the small appliance (counter) circuit. The *9* amps that the
nice *Viking* fridge would draw (peak), when inconveniently timed with
the microwave\'s sudden use, would promptly take out the counter
circuit.

\"Move the microwave elsewhere or get a new DEDICATED branch circuit
installed -- like every NEW home!\"

[I\'ve heard this complaint (counter breaker tripping) so often that
my stock response is: \"Check to see if your refrigerator is on the
same branch circuit\" as it almost always is (and appliance salesmen
aren\'t keen on telling you that you need an electrician to come
out and install a new branch circuit BEFORE they can sell you that
shiny new fridge!)]

Ditto for a freezer, etc.

But, people don\'t read the Code so don\'t understand what it tries to
anticipate... (\"Gee, this only draws X << 20A so I can put it on
the counter circuit!\")

None of that advice applies to the California Electric Code (CEC). All branch circuits into the kitchen are required to have AFCI protection without exception.

What does that have to do with my above comments?

The issues are orthogonal. Can you put a dishwasher
and refrigerator on the same branch circuit, in california,
EVEN IF AFCI PROTECTED?

An AFCI does nothing for the AMPACITY of a branch circuit
which is why the requirement for dedicated branch circuits
exists. AFCI\'s protect against a different type of fault
in the same way as GFCIs.

 

[Don Y]

On 9/25/2023 9:05 AM, Eddy Lee wrote:
> If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.

What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)

 

[Eddy Lee]

On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:

On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)

Fridge: 310KWhr/year = 35W average (no info on motor)
Microwave: 1500W
Laptops: 60W to 90W.

No dishwasher or coffee pot.

 

[Don Y]

On 9/25/2023 11:44 AM, Eddy Lee wrote:

On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:
On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)

Fridge: 310KWhr/year = 35W average (no info on motor)

Branch circuits care very little about the AVERAGE power.
I suspect the power cord is a fair bit larger than 22AWG?

You need to find the nameplate declaration of maximum power
required. Refrigerator power requirements are all over
the map. Note that startup power requirements can be 2-3X
running power (you can look at the compressor\'s locked rotor
current for a worst case value; of course, with all the
electronics now migrating into appliances, the compressor
isn\'t just the sole/primary load!)

Microwave: 1500W
Laptops: 60W to 90W.

And you have *10* of those on that same branch circuit?
That\'s 600-900W *there*.

> No dishwasher or coffee pot.

Dishwasher would be on its own circuit -- though it can
be (\"just\") a 15A circuit -- as can the refrigerator.
(and, unless hardwired -- which is highly unlikely -- would
need a *single* outlet... NOT a duplex receptacle)

It\'s important in that, while running, it consumes some of the
available power *into* your residence.

[Anyone who has lived in a dorm room can appreciate \"active
power management\"! :-( ]

Note that home energy usage has evolved, considerably.
When I was a kid, a single 15A \"outlet circuit\" could easily
power ALL of the bedrooms in a home. Now, everyone has
a personal TV, personal computer, etc. Bedrooms are used
for more than just the bedside radio and lamp.

 

[Ricky]

On Monday, September 25, 2023 at 2:44:39 PM UTC-4, Eddy Lee wrote:

On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:
On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)
Fridge: 310KWhr/year = 35W average (no info on motor)
Microwave: 1500W
Laptops: 60W to 90W.

No dishwasher or coffee pot.

I like that you provided the \"average\" power draw of the fridge. How do you expect to use that in solving your problem?

It just occurred to me. You have the fridge to chill all the laptops so you can overclock them!!!

Here\'s the most direct route to solving your problem. Get a microwave that is 600 watts, rather than the behemoth 1500 watt monster. Do you actual defrost turkeys in it?

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Ralph Mowery]

In article <uesltr$22gfl$2@dont-email.me>, blockedofcourse@foo.invalid
says...

[Anyone who has lived in a dorm room can appreciate \"active
power management\"! :-( ]

When my son was in a dorm room he could rent what they called a
\'microfrige\'. It was a microwave on top of a small refrigerator. I
would assume it was set up so both of them were not drawing power at the
same time. Due to the cost of the rent we decided just to buy a
microwave an small refrigerator.

 

[Ricky]

On Monday, September 25, 2023 at 3:34:16 PM UTC-4, Ralph Mowery wrote:

In article <uesltr$22gfl$2...@dont-email.me>, blocked...@foo.invalid
says...

[Anyone who has lived in a dorm room can appreciate \"active
power management\"! :-( ]



When my son was in a dorm room he could rent what they called a
\'microfrige\'. It was a microwave on top of a small refrigerator. I
would assume it was set up so both of them were not drawing power at the
same time. Due to the cost of the rent we decided just to buy a
microwave an small refrigerator.

I think that\'s an overly large assumption. That tiny refrigerator probably draws 100W when running. It has no defrost. The microwave is likely 600W and just barely makes popcorn. No need at all to worry with the two running at the same time.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Don Y]

On 9/25/2023 12:34 PM, Ralph Mowery wrote:

In article <uesltr$22gfl$2@dont-email.me>, blockedofcourse@foo.invalid
says...

[Anyone who has lived in a dorm room can appreciate \"active
power management\"! :-( ]

When my son was in a dorm room he could rent what they called a
\'microfrige\'. It was a microwave on top of a small refrigerator. I
would assume it was set up so both of them were not drawing power at the
same time. Due to the cost of the rent we decided just to buy a
microwave an small refrigerator.

No microwaves when I was in school. But, our kitchen had a
(laughably) small refrigerator. Silly considering college kids
likely used the fridge more than the stove (oven? what\'s THAT??)

I\'m not sure how much \"smarts\" I would read into a combination
product\'s design. It may literally be little more than a
simple repackaging of two *independant* products into a more
convenient form factor.

E.g., our fridge has three evaporators but one compressor.
I wouldn\'t be surprised if the control algorithm was much
more than:
if (any zone calls for cooling)
compressor(on)
(where compressor() had buried state that included a timer
since last activation)

Too often, control algorithms are naive and live entirely
in the moment. E.g., your irrigation system *may* cut back
on water use if it detects that it has rained, recently.
*BUT*, will gleefully water your flora despite the
growing storm clouds overhead! (isn\'t watering just BEFORE
a rain as wasteful as just after?)

Sad that so many products don\'t \"open\" their implementations
as I\'m sure there are lots of optimizations that are possible
with multiple eyes/criteria looking at a problem!

 

[Lasse Langwadt Christensen]

mandag den 25. september 2023 kl. 20.44.39 UTC+2 skrev Eddy Lee:

On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:
On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)
Fridge: 310KWhr/year = 35W average (no info on motor)

probably more that 20x that when running (google says US average fridge is 725W),
and the start up current can be 3x that

> Microwave: 1500W

the start up current can be 3x that for a few cycles

Laptops: 60W to 90W.

No dishwasher or coffee pot.

(725+1500+60*10)/120V = 23.5A that\'s more than 20A .....

the AIC rating really only matters in a dead short

 

[Lasse Langwadt Christensen]

mandag den 25. september 2023 kl. 22.07.41 UTC+2 skrev Don Y:

On 9/25/2023 12:34 PM, Ralph Mowery wrote:
In article <uesltr$22gfl$2...@dont-email.me>, blocked...@foo.invalid
says...

[Anyone who has lived in a dorm room can appreciate \"active
power management\"! :-( ]

When my son was in a dorm room he could rent what they called a
\'microfrige\'. It was a microwave on top of a small refrigerator. I
would assume it was set up so both of them were not drawing power at the
same time. Due to the cost of the rent we decided just to buy a
microwave an small refrigerator.
No microwaves when I was in school. But, our kitchen had a
(laughably) small refrigerator. Silly considering college kids
likely used the fridge more than the stove (oven? what\'s THAT??)

I\'m not sure how much \"smarts\" I would read into a combination
product\'s design. It may literally be little more than a
simple repackaging of two *independant* products into a more
convenient form factor.

E.g., our fridge has three evaporators but one compressor.
I wouldn\'t be surprised if the control algorithm was much
more than:
if (any zone calls for cooling)
compressor(on)
(where compressor() had buried state that included a timer
since last activation)

Too often, control algorithms are naive and live entirely
in the moment. E.g., your irrigation system *may* cut back
on water use if it detects that it has rained, recently.
*BUT*, will gleefully water your flora despite the
growing storm clouds overhead! (isn\'t watering just BEFORE
a rain as wasteful as just after?)

Sad that so many products don\'t \"open\" their implementations
as I\'m sure there are lots of optimizations that are possible
with multiple eyes/criteria looking at a problem!

and while you are busy optimising the irrigation system the plans dry out and die

there\'s; too late, too expensive and good enough

 

[Eddy Lee]

On Monday, September 25, 2023 at 12:31:34 PM UTC-7, Ricky wrote:

On Monday, September 25, 2023 at 2:44:39 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:
On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)
Fridge: 310KWhr/year = 35W average (no info on motor)
Microwave: 1500W
Laptops: 60W to 90W.

No dishwasher or coffee pot.
I like that you provided the \"average\" power draw of the fridge. How do you expect to use that in solving your problem?

You answered your question in another post:

\"Typically a refrigerator runs on 35% duty cycle, (65% for a freezer). This means that if you take the running watts and multiply it by 35%, you can get an idea as to how much power the average running amps will be.\"

> It just occurred to me. You have the fridge to chill all the laptops so you can overclock them!!!

Not really. They are air-cooled.

> Here\'s the most direct route to solving your problem. Get a microwave that is 600 watts, rather than the behemoth 1500 watt monster. Do you actual defrost turkeys in it?

It\'s fairly standard sized microwave.

I still don\'t understand Fred\'s concern about relay switching the fridge. I got some 30A relay contacts that should be enough. Half of the laptops have batteries, which I can also relay switch off while using the microwave.

 

[Don Y]

On 9/25/2023 1:23 PM, Lasse Langwadt Christensen wrote:

mandag den 25. september 2023 kl. 22.07.41 UTC+2 skrev Don Y:
On 9/25/2023 12:34 PM, Ralph Mowery wrote:
In article <uesltr$22gfl$2...@dont-email.me>, blocked...@foo.invalid
says...

[Anyone who has lived in a dorm room can appreciate \"active
power management\"! :-( ]

When my son was in a dorm room he could rent what they called a
\'microfrige\'. It was a microwave on top of a small refrigerator. I
would assume it was set up so both of them were not drawing power at the
same time. Due to the cost of the rent we decided just to buy a
microwave an small refrigerator.
No microwaves when I was in school. But, our kitchen had a
(laughably) small refrigerator. Silly considering college kids
likely used the fridge more than the stove (oven? what\'s THAT??)

I\'m not sure how much \"smarts\" I would read into a combination
product\'s design. It may literally be little more than a
simple repackaging of two *independant* products into a more
convenient form factor.

E.g., our fridge has three evaporators but one compressor.
I wouldn\'t be surprised if the control algorithm was much
more than:
if (any zone calls for cooling)
compressor(on)
(where compressor() had buried state that included a timer
since last activation)

Too often, control algorithms are naive and live entirely
in the moment. E.g., your irrigation system *may* cut back
on water use if it detects that it has rained, recently.
*BUT*, will gleefully water your flora despite the
growing storm clouds overhead! (isn\'t watering just BEFORE
a rain as wasteful as just after?)

Sad that so many products don\'t \"open\" their implementations
as I\'m sure there are lots of optimizations that are possible
with multiple eyes/criteria looking at a problem!

and while you are busy optimising the irrigation system the plans dry out and die

Because you are incapable of using existing technology while
developing newer? Sounds like a pretty limited intellectual capacity...
walk/chew (gum) -- pick one...

> there\'s; too late, too expensive and good enough

When you live where lack of water is a REAL issue, you think twice about
how it is misused or underutilized. \"Good enough\" works when there *is*
enough!

 

[Ricky]

On Monday, September 25, 2023 at 4:25:39 PM UTC-4, Eddy Lee wrote:

On Monday, September 25, 2023 at 12:31:34 PM UTC-7, Ricky wrote:
On Monday, September 25, 2023 at 2:44:39 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:
On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)
Fridge: 310KWhr/year = 35W average (no info on motor)
Microwave: 1500W
Laptops: 60W to 90W.

No dishwasher or coffee pot.
I like that you provided the \"average\" power draw of the fridge. How do you expect to use that in solving your problem?
You answered your question in another post:

\"Typically a refrigerator runs on 35% duty cycle, (65% for a freezer). This means that if you take the running watts and multiply it by 35%, you can get an idea as to how much power the average running amps will be.\"

I\'m pretty sure I didn\'t post that. Regardless, that would be a combination of an average with a rule of thumb, so not of much value. The point is, your appliance has a plate with the actual power rating while running. Why don\'t you look at that? Not the motor, the appliance. You\'ve also said nothing about the size of this appliance. Is it a dorm room size fridge? A massive double door kitchen behemoth? Something in between? As is usual with you, only the barest minimum of information is provided and then the guessing begins.

It just occurred to me. You have the fridge to chill all the laptops so you can overclock them!!!
Not really. They are air-cooled.

LOL!

Here\'s the most direct route to solving your problem. Get a microwave that is 600 watts, rather than the behemoth 1500 watt monster. Do you actual defrost turkeys in it?
It\'s fairly standard sized microwave.

1500W is not a standard size microwave. That\'s as large as they get for home use. 600W to 1000W is much more typical. Should I assume you actually read the rating plate to get the 1500W number? Or is this another \"average\" you pulled off a web page, somewhere?


> I still don\'t understand Fred\'s concern about relay switching the fridge. I got some 30A relay contacts that should be enough. Half of the laptops have batteries, which I can also relay switch off while using the microwave.

You will wear out the relays in relatively short order. Maybe a few months, maybe a year, depending on how often you use the microwave. The current rating does not mean you can open the circuit under load as much as you want. Especially with motors, this causes an arc across the contacts, eroding and pitting them severely in a small number of cycles.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[Eddy Lee]

On Monday, September 25, 2023 at 1:39:33 PM UTC-7, Ricky wrote:

On Monday, September 25, 2023 at 4:25:39 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 12:31:34 PM UTC-7, Ricky wrote:
On Monday, September 25, 2023 at 2:44:39 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:
On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine.. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)
Fridge: 310KWhr/year = 35W average (no info on motor)
Microwave: 1500W
Laptops: 60W to 90W.

No dishwasher or coffee pot.
I like that you provided the \"average\" power draw of the fridge. How do you expect to use that in solving your problem?
You answered your question in another post:

\"Typically a refrigerator runs on 35% duty cycle, (65% for a freezer). This means that if you take the running watts and multiply it by 35%, you can get an idea as to how much power the average running amps will be.\"
I\'m pretty sure I didn\'t post that. Regardless, that would be a combination of an average with a rule of thumb, so not of much value. The point is, your appliance has a plate with the actual power rating while running. Why don\'t you look at that? Not the motor, the appliance. You\'ve also said nothing about the size of this appliance. Is it a dorm room size fridge? A massive double door kitchen behemoth? Something in between? As is usual with you, only the barest minimum of information is provided and then the guessing begins.

There is an energy guide tag saying 310 KWhr/year. Nothing else. Detail info might be at the back of the fridge. Too heavy to pull the fridge out when loaded.

We just need to agree that it\'s too much to have both the fridge and microwave running together.

It just occurred to me. You have the fridge to chill all the laptops so you can overclock them!!!
Not really. They are air-cooled.
LOL!
Here\'s the most direct route to solving your problem. Get a microwave that is 600 watts, rather than the behemoth 1500 watt monster. Do you actual defrost turkeys in it?
It\'s fairly standard sized microwave.
1500W is not a standard size microwave. That\'s as large as they get for home use. 600W to 1000W is much more typical. Should I assume you actually read the rating plate to get the 1500W number? Or is this another \"average\" you pulled off a web page, somewhere?

Yes, rating plate at the back of the microwave.

I still don\'t understand Fred\'s concern about relay switching the fridge. I got some 30A relay contacts that should be enough. Half of the laptops have batteries, which I can also relay switch off while using the microwave.
You will wear out the relays in relatively short order. Maybe a few months, maybe a year, depending on how often you use the microwave. The current rating does not mean you can open the circuit under load as much as you want. Especially with motors, this causes an arc across the contacts, eroding and pitting them severely in a small number of cycles.

5 to 10 times per day. 3000 per year. It should last at least a year.
I will put a filter cap in parallel with the contacts.

 

[Tabby]

On Monday, 25 September 2023 at 09:39:26 UTC+1, Ricky wrote:

> The only individual heavy load is the microwave which ranges from 600W to 1,400W, depending on size.

Output. Consumption is about 1.2kW - 2kW

 

[Ricky]

On Monday, September 25, 2023 at 4:57:02 PM UTC-4, Eddy Lee wrote:

On Monday, September 25, 2023 at 1:39:33 PM UTC-7, Ricky wrote:
On Monday, September 25, 2023 at 4:25:39 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 12:31:34 PM UTC-7, Ricky wrote:
On Monday, September 25, 2023 at 2:44:39 PM UTC-4, Eddy Lee wrote:
On Monday, September 25, 2023 at 11:22:16 AM UTC-7, Don Y wrote:
On 9/25/2023 9:05 AM, Eddy Lee wrote:
If I unplug the fridge, or when it\'s silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.
What\'s the nameplate rating of the microwave? Does *it* say
it requires a dedicated circuit? (because it draws more than
half of the rated branch circuit\'s ampacity)

The countertops, in kitchens, tend to see lots of large
loads that are often running concurrently. Toaster,
toaster oven, countertop oven (e.g., all the toaster
ovens on steroids that you see advertised on TV),
stand/hand mixer, electric frying pan, *TV*, etc.

Add to this the other large loads that folks tend to
think nothing of activating: dishwasher, garbage disposal,
microwave, \"instant hot water\", etc. Imagine mindlessly
turning on the garbage disposal (for 10 seconds) and
tripping a breaker because it shared a branch circuit
with some other appliance...

You *don\'t* want to unplug/replug the refrigerator
(which is what a relay would do) as this can confuse
the defrost timer and (for poorly designed controls)
lead to the compressor starting under a (mechanical)
load that hasn\'t yet had time to dissipate (smart
controls will inhibit the compressor for its required
dead time on initial application of power for exactly
this reason -- but, then, you would risk the compressor
always \"waiting\" even without cause)

[Microwave ovens tend to see frequent, brief use.
Would you want your refrigerator being unplugged
each time you throw something in the microwave
for 15 seconds?]

And, refrigerators (if disabled due to a tripped breaker)
risk having their contents spoil. So, you\'d like the
refrigerator to be the sole item that can cause *its*
breaker to trip (imagine the instant hot water unit
thermostatically cycled on and silently took out the
breaker for the refrigerator... which you happen to
discover the next *morning*). Ditto the dishwasher
or any other appliance that can \"safely\" sit, powered
off, with no ill effects (e.g., the dishes are still dirty
but aren\'t getting any *dirtier* in the absence of mains!)
Fridge: 310KWhr/year = 35W average (no info on motor)
Microwave: 1500W
Laptops: 60W to 90W.

No dishwasher or coffee pot.
I like that you provided the \"average\" power draw of the fridge. How do you expect to use that in solving your problem?
You answered your question in another post:

\"Typically a refrigerator runs on 35% duty cycle, (65% for a freezer).. This means that if you take the running watts and multiply it by 35%, you can get an idea as to how much power the average running amps will be.\"
I\'m pretty sure I didn\'t post that. Regardless, that would be a combination of an average with a rule of thumb, so not of much value. The point is, your appliance has a plate with the actual power rating while running. Why don\'t you look at that? Not the motor, the appliance. You\'ve also said nothing about the size of this appliance. Is it a dorm room size fridge? A massive double door kitchen behemoth? Something in between? As is usual with you, only the barest minimum of information is provided and then the guessing begins.
There is an energy guide tag saying 310 KWhr/year. Nothing else. Detail info might be at the back of the fridge. Too heavy to pull the fridge out when loaded.

Ok, but that\'s not the same as \"nothing else\". It just means you don\'t know the wattage and you won\'t do what it takes to find it. Can you read a model number somewhere? Did you look inside the fridge?

You still didn\'t say how large the unit is, but I suppose it\'s not a small unit if you can\'t move it. Maybe buy less groceries and eat your way to lightening it?


> We just need to agree that it\'s too much to have both the fridge and microwave running together.

That\'s not the question.

It just occurred to me. You have the fridge to chill all the laptops so you can overclock them!!!
Not really. They are air-cooled.
LOL!
Here\'s the most direct route to solving your problem. Get a microwave that is 600 watts, rather than the behemoth 1500 watt monster. Do you actual defrost turkeys in it?
It\'s fairly standard sized microwave.
1500W is not a standard size microwave. That\'s as large as they get for home use. 600W to 1000W is much more typical. Should I assume you actually read the rating plate to get the 1500W number? Or is this another \"average\" you pulled off a web page, somewhere?
Yes, rating plate at the back of the microwave.

Ok, end of discussion. You only have a small amount of reserve on your 20 amp line when the microwave is in use. I doubt you can use the ten laptops with the microwave.

So now, the only question is if the laptops can be used with the fridge. If so, you need to circuits. If not, you need three.

I still don\'t understand Fred\'s concern about relay switching the fridge. I got some 30A relay contacts that should be enough. Half of the laptops have batteries, which I can also relay switch off while using the microwave.
You will wear out the relays in relatively short order. Maybe a few months, maybe a year, depending on how often you use the microwave. The current rating does not mean you can open the circuit under load as much as you want. Especially with motors, this causes an arc across the contacts, eroding and pitting them severely in a small number of cycles.
5 to 10 times per day. 3000 per year. It should last at least a year.
I will put a filter cap in parallel with the contacts.

Good luck and enjoy

--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

 

[Ricky]

On Monday, September 25, 2023 at 7:39:07 PM UTC-4, Tabby wrote:

On Monday, 25 September 2023 at 09:39:26 UTC+1, Ricky wrote:

The only individual heavy load is the microwave which ranges from 600W to 1,400W, depending on size.
Output. Consumption is about 1.2kW - 2kW

I\'ve never seen a 120V appliance draw over 1440W. But then here it\'s very uncommon to see 20A circuits.

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209