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Guest

Mon Feb 24, 2020 11:45 am   



Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

However, these lights claim to have an average current draw of
393W3%. My meter says 765W... and I tested two identical model lights
with the same result.

I'm no electronics expert, but IMO either the light's stated specs are
way off, or the light is somehow causing an inaccurate reading.

Thanks for any sensible comments.

~misfit~
Guest

Mon Feb 24, 2020 12:45 pm   



On 24/02/2020 11:37 pm, Je�us wrote:
Quote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

However, these lights claim to have an average current draw of
393W±3%. My meter says 765W... and I tested two identical model lights
with the same result.

I'm no electronics expert, but IMO either the light's stated specs are
way off, or the light is somehow causing an inaccurate reading.

Thanks for any sensible comments.


Does your meter show power factor? Maybe they have poor power factor and the meter is showing
'apparent power'?
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy little classification
in the DSM"
David Melville

This is not an email and hasn't been checked for viruses by any half-arsed self-promoting software.


Guest

Mon Feb 24, 2020 10:45 pm   



On Tue, 25 Feb 2020 00:24:23 +1300, ~misfit~
<shaun.at.pukekohe_at_gmail.com> wrote:

Quote:
On 24/02/2020 11:37 pm, Je?us wrote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

However, these lights claim to have an average current draw of
393W3%. My meter says 765W... and I tested two identical model lights
with the same result.

I'm no electronics expert, but IMO either the light's stated specs are
way off, or the light is somehow causing an inaccurate reading.

Thanks for any sensible comments.

Does your meter show power factor? Maybe they have poor power factor and the meter is showing
'apparent power'?


Don't think so, I'll have to check the meter again later when i get a
chance, thanks for your input.

Jasen Betts
Guest

Tue Feb 25, 2020 7:43 am   



On 2020-02-24, Jeßus <j_at_j.net> wrote:
Quote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.


Current could be pulsed, that would cause RMS current to be higher
than average current but a cheap merater is going to read average
current.

Quote:
However, these lights claim to have an average current draw of
393W±3%. My meter says 765W... and I tested two identical model lights
with the same result.


Not a current draw...

What equipment do you have? What measurement did you make? How?

--
Jasen.

Trevor Wilson
Guest

Tue Feb 25, 2020 8:45 pm   



On 24/02/2020 9:37 pm, Je�us wrote:
Quote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

However, these lights claim to have an average current draw of
393W±3%. My meter says 765W... and I tested two identical model lights
with the same result.

I'm no electronics expert, but IMO either the light's stated specs are
way off, or the light is somehow causing an inaccurate reading.

Thanks for any sensible comments.


**~misfit~ is correct. A standard El Cheapo™ meter will not be suitable
for measurements that involve switching power supplies (almost always
the type used with modern products. You will need a GOOD QUALITY, 'True
RMS' type of meter.

--
Trevor Wilson
www.rageaudio.com.au

Phil Allison
Guest

Tue Feb 25, 2020 10:45 pm   



Trevor Wilson wrote:
------------------

Quote:

**~misfit~ is correct. A standard El Cheapo™ meter will not be suitable
for measurements that involve switching power supplies (almost always
the type used with modern products. You will need a GOOD QUALITY, 'True
RMS' type of meter.



** RMS meters read *higher* than other type with the spiky current waveforms found in SMRSs.

The only "el cheapo" Arlec power meter on sale is a full function type with watts, amps and power factor readings.

However, if the OP's dope growing light has a significant level of switching frequency noise riding on the AC current, the meter might well over read on amps and watts.

FYI such meters use sampling of instantaneous current and voltage to compute watts etc using a uP.


...... Phil


Guest

Wed Feb 26, 2020 8:45 am   



On Tue, 25 Feb 2020 05:43:11 -0000 (UTC), Jasen Betts
<jasen_at_xnet.co.nz> wrote:

Quote:
On 2020-02-24, Jeus <j_at_j.net> wrote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

Current could be pulsed, that would cause RMS current to be higher
than average current but a cheap merater is going to read average
current.

However, these lights claim to have an average current draw of
393W3%. My meter says 765W... and I tested two identical model lights
with the same result.

Not a current draw...

What equipment do you have? What measurement did you make? How?


I used one of these:
https://www.bunnings.com.au/arlec-energy-cost-electrical-meter_p4410270
It'd be nice to have something better, but I can't really justify the
cost given the amount of use it'll get.


Guest

Wed Feb 26, 2020 8:45 am   



On Wed, 26 Feb 2020 06:36:18 +1100, Trevor Wilson
<trevor_at_rageaudio.com.au> wrote:

Quote:
On 24/02/2020 9:37 pm, Je?us wrote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

However, these lights claim to have an average current draw of
393W3%. My meter says 765W... and I tested two identical model lights
with the same result.

I'm no electronics expert, but IMO either the light's stated specs are
way off, or the light is somehow causing an inaccurate reading.

Thanks for any sensible comments.


**~misfit~ is correct. A standard El Cheapo meter will not be suitable
for measurements that involve switching power supplies (almost always
the type used with modern products. You will need a GOOD QUALITY, 'True
RMS' type of meter.


Yes, that would remove any doubt. Can't think of anyone local enough
to me who might have one...

Phil Allison
Guest

Wed Feb 26, 2020 9:45 am   



Trevor Wilson wrote:

---------------------

> **~misfit~ is correct.

** No he isn't.

> A standard El Cheapo™ meter will not be suitable

** FFS its a high tech, sampling, digital multi-function, uP based, Arlec powermeter.


Quote:
for measurements that involve switching power supplies (almost always
the type used with modern products. You will need a GOOD QUALITY, 'True
RMS' type of meter.


** Go SFA to do with measuring power.

The OP is so utterly brain dead from smoking dope he has completely mixed up "watts" and "amps".

In reactive or non sine wave circuits the two are unrelated.


...... Phil

~misfit~
Guest

Wed Feb 26, 2020 11:45 am   



On 26/02/2020 8:06 pm, Je�us wrote:
Quote:
On Tue, 25 Feb 2020 05:43:11 -0000 (UTC), Jasen Betts
jasen_at_xnet.co.nz> wrote:

On 2020-02-24, Jeßus <j_at_j.net> wrote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

Current could be pulsed, that would cause RMS current to be higher
than average current but a cheap merater is going to read average
current.

However, these lights claim to have an average current draw of
393W±3%. My meter says 765W... and I tested two identical model lights
with the same result.

Not a current draw...

What equipment do you have? What measurement did you make? How?

I used one of these:
https://www.bunnings.com.au/arlec-energy-cost-electrical-meter_p4410270
It'd be nice to have something better, but I can't really justify the
cost given the amount of use it'll get.


I have one of those and it's surprisingly accurate. It shows power factor (bottom left of screen in
pic at link, showing 100).

If it is indeed set on Watts then I'd say your LEDS are drawing what it reads +/- 10%.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy little classification
in the DSM"
David Melville

This is not an email and hasn't been checked for viruses by any half-arsed self-promoting software.


Guest

Wed Feb 26, 2020 11:45 pm   



On Wed, 26 Feb 2020 22:45:54 +1300, ~misfit~
<shaun.at.pukekohe_at_gmail.com> wrote:

Quote:
On 26/02/2020 8:06 pm, Je?us wrote:
On Tue, 25 Feb 2020 05:43:11 -0000 (UTC), Jasen Betts
jasen_at_xnet.co.nz> wrote:

On 2020-02-24, Jeus <j_at_j.net> wrote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

Current could be pulsed, that would cause RMS current to be higher
than average current but a cheap merater is going to read average
current.

However, these lights claim to have an average current draw of
393W3%. My meter says 765W... and I tested two identical model lights
with the same result.

Not a current draw...

What equipment do you have? What measurement did you make? How?

I used one of these:
https://www.bunnings.com.au/arlec-energy-cost-electrical-meter_p4410270
It'd be nice to have something better, but I can't really justify the
cost given the amount of use it'll get.

I have one of those and it's surprisingly accurate.


Mine seems to be accurate on anything else I try, but there's a huge
discrepancy between the claimed specs and what my Arlec is measuring
on these lights.

Quote:
It shows power factor (bottom left of screen in
pic at link, showing 100).

If it is indeed set on Watts then I'd say your LEDS are drawing what it reads +/- 10%.


Power factor was 94: https://postimg.cc/cgbzqDgx

I've contacted the manufacturers about it and they seem keen to get
them back, paying for the return shipping, etc.

~misfit~
Guest

Thu Feb 27, 2020 12:45 am   



On 27/02/2020 11:19 am, Je�us wrote:
Quote:
On Wed, 26 Feb 2020 22:45:54 +1300, ~misfit~
shaun.at.pukekohe_at_gmail.com> wrote:

On 26/02/2020 8:06 pm, Je?us wrote:
On Tue, 25 Feb 2020 05:43:11 -0000 (UTC), Jasen Betts
jasen_at_xnet.co.nz> wrote:

On 2020-02-24, Jeßus <j_at_j.net> wrote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

Current could be pulsed, that would cause RMS current to be higher
than average current but a cheap merater is going to read average
current.

However, these lights claim to have an average current draw of
393W±3%. My meter says 765W... and I tested two identical model lights
with the same result.

Not a current draw...

What equipment do you have? What measurement did you make? How?

I used one of these:
https://www.bunnings.com.au/arlec-energy-cost-electrical-meter_p4410270
It'd be nice to have something better, but I can't really justify the
cost given the amount of use it'll get.

I have one of those and it's surprisingly accurate.

Mine seems to be accurate on anything else I try, but there's a huge
discrepancy between the claimed specs and what my Arlec is measuring
on these lights.


Then I'd suggest the lights are suspect.

Quote:
It shows power factor (bottom left of screen in
pic at link, showing 100).

If it is indeed set on Watts then I'd say your LEDS are drawing what it reads +/- 10%.

Power factor was 94: https://postimg.cc/cgbzqDgx


That's a good power factor.

Quote:
I've contacted the manufacturers about it and they seem keen to get
them back, paying for the return shipping, etc.


How unusual! Perhaps the sent you more powerful (and expensive) lights than you ordered?
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy little classification
in the DSM"
David Melville

This is not an email and hasn't been checked for viruses by any half-arsed self-promoting software.

Computer Nerd Kev
Guest

Thu Feb 27, 2020 11:45 pm   



~misfit~ <shaun.at.pukekohe_at_gmail.com> wrote:
Quote:
On 27/02/2020 11:19 am, Je?us wrote:

I've contacted the manufacturers about it and they seem keen to get
them back, paying for the return shipping, etc.

How unusual! Perhaps the sent you more powerful (and expensive)
lights than you ordered?


If both the reading and the labelling is correct and they are
supposed to consume half of the power that they are doing, then
they would likely overheat and potentially set fire to something.

The manufacturers might be afraid of being sued if the lights set
fire to someone's house.

A mistake with the rating printed on the label is more likely though,
or that your meter is simply confused by the switch-mode current
limiting.

--
__ __
#_ < |\| |< _#

news18
Guest

Fri Feb 28, 2020 1:45 am   



On Thu, 27 Feb 2020 22:07:03 +0000, Computer Nerd Kev wrote:


Quote:
A mistake with the rating printed on the label is more likely though,
or that your meter is simply confused by the switch-mode current
limiting.


If it was a 'Dick Smith' meter then that wouddefinitely be the reason.
I've got on the gives V/2 on a battery, let alone a plug plack I'm
testing.

keithr0
Guest

Fri Feb 28, 2020 11:45 am   



On 2/24/2020 8:37 PM, Je�us wrote:
Quote:
Greetings.

Getting to the point - is there anything about modern LED grow lights
that could cause inaccurate amperage measurements? I have an elcheapo
Arlec meter, when testing it on other devices, it's readings are
consistent with the devices stated current draw. So I assume the meter
is accurate.

However, these lights claim to have an average current draw of
393W±3%. My meter says 765W... and I tested two identical model lights
with the same result.


Watts are a measure of power not current, but never mind, the
discrepancy could well be interference from the switching power supply.

Quote:
I'm no electronics expert, but IMO either the light's stated specs are
way off, or the light is somehow causing an inaccurate reading.

Thanks for any sensible comments.


Goto page 1, 2  Next

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