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Ah no, I wasn't following it all - you know a PICAXE can also send RS232On Dec 15, 8:09 pm, David Eather<eat...@tpg.com.au> wrote:
On 16/12/2011 7:46 AM, linnix wrote:
On Dec 15, 12:19 pm, David Eather<eat...@tpg.com.au> wrote:
On 15/12/2011 10:17 AM, linnix wrote:
On Dec 14, 3:22 pm, Sylvia Else<syl...@not.here.invalid> wrote:
On 10/12/2011 9:28 PM, Sylvia Else wrote:
On 10/12/2011 10:14 AM, David Eather wrote:
On 9/12/2011 10:56 AM, Sylvia Else wrote:
On 9/12/2011 4:23 AM, linnix wrote:
On Dec 8, 9:01 am, Fred Bloggs<bloggs.fredbloggs.f...@gmail.com
wrote:
On Dec 8, 1:50 am, Sylvia Else<syl...@not.here.invalid> wrote:
The defrost timer in my fridge is failing, and given the cost of a
'genuine' replacement part, I was pondering the option of making
electronic timer driving an electromechanical relay.
It probably won't happen, but when I was looking at relay specs, I
found
that their ratings are usually specified as a highish reactive power,
and a much lower real power.
http://australia.rs-online.com/web/p/electromechanical-relays/1279550/
is typical, specifying in this case 300 W / 2500 VA.
I find this difficult to fathom. Imagine a purely inductive 2500VA
load.
So no real power being switched, but it would arc like crazy. What
am I
missing here?
Sylvia.
There are aftermarket universals better than the OEM
parthttp://compare.ebay.com/like/290638915750?var=lv<yp=AllFixedPriceIt...
There are plenty of relays you can salvage out of garage opener (12V),
microwave (12V) or furnace (24V). Add a micro or 555 for less than $5
and you are done. I am doing one for my furnace timer.
Not sure about getting a 555 to run at 1 cycle per six hours.
A PIC would no doubt do the job easily, but then I'd have to invest in
hardware to program it.
Sylvia.
Sylvia,
Try a PICAXE 08M2 - it costs $2.50 in one off's and programs in BASIC.
Software and examples are free fromwww.picaxe.co.uk
It is not uncommon for people totally new to the PICAXE have had them
running programs within 30 minutes of getting their first chip.
The only stuff you need to program one is a serial port (RS232 or TTL
level) and a resistor.
Interesting. Thanks.
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.
http://australia.rs-online.com/web/p/microcontroller-processor/0381582/
PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.
Sylvia.
Get the PICKIT 3 for $7 more, in case you want to program PIC24 or
PIC32. Not sure if PICKIT 2 can program them.
http://australia.rs-online.com/web/p/microcontroller-processor/687275....
$7 more than what?
PICKIT 3 vs. PICKIT 2 is around $7 to $8 more.
Ah. Got you. And (IIRC) you are correct that a PICKIT 2 won't do PIC24.
My response was in regard to SE's aims for a fridge controller. I don't
know what your requirement was.
I am also trying to rebuild my busted fridge, with a more intelligent
defrost controller. I don't know if you are following the other
discussions. We are trying to measure the compressor efficiency and
temperature difference, in order to minimize heating and cooling
cycles. To do so, we need to have several thermistors readings and to
keep track of past operating cycles. At a minimum, the user would
need to be able to set the fridge target temperature, as well as other
operating parameters. I don't think the PICAXE is sufficient for
this.
I am also trying to rebuild my busted fridge, with a more intelligentOn 16/12/2011 7:46 AM, linnix wrote:
On Dec 15, 12:19 pm, David Eather<eat...@tpg.com.au> wrote:
On 15/12/2011 10:17 AM, linnix wrote:
On Dec 14, 3:22 pm, Sylvia Else<syl...@not.here.invalid> wrote:
On 10/12/2011 9:28 PM, Sylvia Else wrote:
On 10/12/2011 10:14 AM, David Eather wrote:
On 9/12/2011 10:56 AM, Sylvia Else wrote:
On 9/12/2011 4:23 AM, linnix wrote:
On Dec 8, 9:01 am, Fred Bloggs<bloggs.fredbloggs.f...@gmail.com
wrote:
On Dec 8, 1:50 am, Sylvia Else<syl...@not.here.invalid> wrote:
The defrost timer in my fridge is failing, and given the cost of a
'genuine' replacement part, I was pondering the option of making
electronic timer driving an electromechanical relay.
It probably won't happen, but when I was looking at relay specs, I
found
that their ratings are usually specified as a highish reactive power,
and a much lower real power.
http://australia.rs-online.com/web/p/electromechanical-relays/1279550/
is typical, specifying in this case 300 W / 2500 VA.
I find this difficult to fathom. Imagine a purely inductive 2500VA
load.
So no real power being switched, but it would arc like crazy. What
am I
missing here?
Sylvia.
There are aftermarket universals better than the OEM
parthttp://compare.ebay.com/like/290638915750?var=lv<yp=AllFixedPriceIt...
There are plenty of relays you can salvage out of garage opener (12V),
microwave (12V) or furnace (24V). Add a micro or 555 for less than $5
and you are done. I am doing one for my furnace timer.
Not sure about getting a 555 to run at 1 cycle per six hours.
A PIC would no doubt do the job easily, but then I'd have to invest in
hardware to program it.
Sylvia.
Sylvia,
Try a PICAXE 08M2 - it costs $2.50 in one off's and programs in BASIC.
Software and examples are free fromwww.picaxe.co.uk
It is not uncommon for people totally new to the PICAXE have had them
running programs within 30 minutes of getting their first chip.
The only stuff you need to program one is a serial port (RS232 or TTL
level) and a resistor.
Interesting. Thanks.
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.
http://australia.rs-online.com/web/p/microcontroller-processor/0381582/
PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.
Sylvia.
Get the PICKIT 3 for $7 more, in case you want to program PIC24 or
PIC32. Not sure if PICKIT 2 can program them.
http://australia.rs-online.com/web/p/microcontroller-processor/687275....
$7 more than what?
PICKIT 3 vs. PICKIT 2 is around $7 to $8 more.
Ah. Got you. And (IIRC) you are correct that a PICKIT 2 won't do PIC24.
My response was in regard to SE's aims for a fridge controller. I don't
know what your requirement was.
---On 2011-12-13, John Fields <jfields@austininstruments.com> wrote:
. 4060
. +------+
. +-976K--|Rs MR|-----
. | | |
. +-527K--|Rt |
. | | |
. +-1.0ľF-|Ct Q13|-100n
. +------+
. 4060
. +------+
. +-887k--|Rs MR|-----
. | | |
. +-442k--|Rt |
. | | |
. +-0.1ľF-|Ct Q13|-[100
. +------+
976K?
887K?
1% tolerance parts where 20% tolerance would not measurably effect
the circuit?
Nicely done!I'd do it like this:
4060 +-----+--[100K]--+----------+-- +12
+------+ | | | |
+-3M3---|Rs MR|----+ | relay [/] |
| | | | coil | |
+-1M2---|Rt Q10|-----|<---+ +-->|--+
| | | | |
+-1.0ľF-|Ct Q14|--+--|<---+ |
+------+ | |/
+---3K3----------| BC547
|\|
\
--- 0V
here the defrost time is 23m, 1/16 of
the cooling time which should be close to 6H (if I got my arithmetic right)
Add another diode between Q8 and MR to get 28m
(5/64) and another from Q6 to get even closer to 30m heating
4060
+------+
+-3M3---|Rs MR|----------+--[100k]--+------+--- +12
| | | | | |
| | Q6|-----|<---+ | |
| | | optional | relay[/] |
| | Q8|-----|<---+ coil | |
| | | | | |
+-1M2---|Rt Q10|-----|<---+ +-->|--+
| | | | |
+-1.0ľF-|Ct Q14|--+--|<---+ |
+------+ | |/
+---3K3----------| BC547
|\|
\
--- 0V
---
So can PIC32, or even WiFi via USB. In fact, we might end up tyingOn 16/12/2011 2:53 PM, linnix wrote:
On Dec 15, 8:09 pm, David Eather<eat...@tpg.com.au> wrote:
On 16/12/2011 7:46 AM, linnix wrote:
On Dec 15, 12:19 pm, David Eather<eat...@tpg.com.au> wrote:
On 15/12/2011 10:17 AM, linnix wrote:
On Dec 14, 3:22 pm, Sylvia Else<syl...@not.here.invalid> wrote:
On 10/12/2011 9:28 PM, Sylvia Else wrote:
On 10/12/2011 10:14 AM, David Eather wrote:
On 9/12/2011 10:56 AM, Sylvia Else wrote:
On 9/12/2011 4:23 AM, linnix wrote:
On Dec 8, 9:01 am, Fred Bloggs<bloggs.fredbloggs.f...@gmail.com
wrote:
On Dec 8, 1:50 am, Sylvia Else<syl...@not.here.invalid> wrote:
The defrost timer in my fridge is failing, and given the cost of a
'genuine' replacement part, I was pondering the option of making
electronic timer driving an electromechanical relay.
It probably won't happen, but when I was looking at relay specs, I
found
that their ratings are usually specified as a highish reactive power,
and a much lower real power.
http://australia.rs-online.com/web/p/electromechanical-relays/1279550/
is typical, specifying in this case 300 W / 2500 VA.
I find this difficult to fathom. Imagine a purely inductive 2500VA
load.
So no real power being switched, but it would arc like crazy.. What
am I
missing here?
Sylvia.
There are aftermarket universals better than the OEM
parthttp://compare.ebay.com/like/290638915750?var=lv<yp=AllFixedPriceIt...
There are plenty of relays you can salvage out of garage opener (12V),
microwave (12V) or furnace (24V). Add a micro or 555 for less than $5
and you are done. I am doing one for my furnace timer.
Not sure about getting a 555 to run at 1 cycle per six hours.
A PIC would no doubt do the job easily, but then I'd have to invest in
hardware to program it.
Sylvia.
Sylvia,
Try a PICAXE 08M2 - it costs $2.50 in one off's and programs in BASIC.
Software and examples are free fromwww.picaxe.co.uk
It is not uncommon for people totally new to the PICAXE have had them
running programs within 30 minutes of getting their first chip.
The only stuff you need to program one is a serial port (RS232 or TTL
level) and a resistor.
Interesting. Thanks.
Though on further examination, by the time you've paid the higher cost
for the chip, the postage from the UK, and either bought or made the
cable, it's considerably cheaper just to buy a programmer from a local
supplier.
http://australia.rs-online.com/web/p/microcontroller-processor/0381582/
PICAXE is probably good for people who've little or no experience in
programming, particularly at assembler code level.
Sylvia.
Get the PICKIT 3 for $7 more, in case you want to program PIC24 or
PIC32. Not sure if PICKIT 2 can program them.
http://australia.rs-online.com/web/p/microcontroller-processor/687275....
$7 more than what?
PICKIT 3 vs. PICKIT 2 is around $7 to $8 more.
Ah. Got you. And (IIRC) you are correct that a PICKIT 2 won't do PIC24..
My response was in regard to SE's aims for a fridge controller. I don't
know what your requirement was.
I am also trying to rebuild my busted fridge, with a more intelligent
defrost controller. I don't know if you are following the other
discussions. We are trying to measure the compressor efficiency and
temperature difference, in order to minimize heating and cooling
cycles. To do so, we need to have several thermistors readings and to
keep track of past operating cycles. At a minimum, the user would
need to be able to set the fridge target temperature, as well as other
operating parameters. I don't think the PICAXE is sufficient for
this.
Ah no, I wasn't following it all - you know a PICAXE can also send RS232
to a laptop .. (duck and run)
There are other possibilities. FWIW, I do not _try_ to be obtuse. _If_ and when I am obtuse, it is real effortless.You are a prick for wanting to persecute someone
for learning something.
You're either an idiot or simply trying to be obtuse.
Number of children produced.Mrs Tarbomb, thank you.
Which topic?
No.On Thu, 15 Dec 2011 20:15:02 -0800 (PST), mrst...@gmail.com wrote:
Mrs Tarbomb, thank you.
Which topic?
Number of children produced.
?-)
With ice buildup on the heat exchanger, it will be wasting energy toOn 12/17/2011 10:16 AM, linnix wrote:
if(temp_fridge< temp_target)
I assume you really mean:
if (temp_fridge> temp_target) // fridge too warm; cool it
{
compressor(TRUE);
sleep(TIME_COMPRESSOR);
compressor(FALSE);
Do you really want to run the compressor open loop like this?
Granted, you want it to stay ON for some minimum amount of time
lest you end up forcing it to turnon and off to quickly.
But, you probably also want it to stay *off* for some minimum
time once turned off.
Yes, it does. In fact, the TIME_IDLE is several times more than
TIME_COMPRESSOR here. We know that the compressor is main function of
the fridge, so we need to keep it going often. Yes, we still need to
work out the timing parameters.
Why isn;t the compressor being driven directly by the temperature?
I.e., a control loop that ensures the temperature reaches its
setpoint temperature.
Surprisingly, no. The OP of this thread has a timer based control,if (fridge > target) {
compressor(ON);
sleep(MIN_COMPRESSOR_ON_TIME)
while (fridge > target) {
// twiddle thumbs
}
compressor(OFF)
// check to see if defrost needed
This is still suboptimal as you want to also enforce
MIN_COMPRESSOR_OFF_TIME, etc.
(Multitasking makes things like this just *so* much cleaner!)
Your alorithm (above) could see it
turned back on AS SOON AS it is turned off!
after a TIME_IDLE. Even if not, it's no worst than a dumb open loop
fridge (most existing fridge).
I think existing refrigerators use closed loop temperature
controls. To verify this, time how long the compressor
*tends* to run. Then, open the door *wide* and see how long
it runs (and *if* it ever shuts off!)
Yes, that's why we need a big data stack, as much as 32K bytes. Thetemp_delta = read_temp(2) - read_temp(1);
// push latest value on data stack
push_comp_temp(temp_delta);
WTF? Where's it going? Why do you need it?
Here, we want to push the compressor efficiency onto a data stack.
Namely, how much temperature change did we get for a certain run time.
Fine. But where's the *consumer*? After <some_number> of
iterations of this loop, that stack is going to overflow.
The following function, deciding whether to defrost or not.// if heat exchanger temp. delta is decreased, time to defrost
differential_temp();
Is this computing something? Preumably, it is impacting the return
value of the defrost() invocation which follows.
Yes, computing the slope of the temperature curve. In other words,
how well is the compressor working.
Where is that result? Who uses it?
Yes, will be there when we are ready to post the result. We are stillif(defrost(TRUE))
Turn on defrost, if compressor efficiency is getting low.
OK, presumably determined by the "differential_temp()" invocation.
And, presumably that is also consuming the push_comp_temp()?
None of this is clear from your code
---Yes, will be there when we are ready to post the result. We are still
working on tests and evaluations.
---We are still debating whether we should do it with a low end PIC, or
high end PIC32 just in case we need it.
I always hear that, when people running out of reasoning to argue.On Sat, 17 Dec 2011 12:15:46 -0800 (PST), linnix
m...@linnix.info-for.us> wrote:
Yes, will be there when we are ready to post the result. We are still
working on tests and evaluations.
---
You're doing nothing of the sort; you're trolling and posting
nonsense.
That part is just a joke. I guess you can't take a joke.A hot water heater being used to supply hot water to defrost a fridge
every time a toilet is flushed?
Yes, that why we should start with PIC32 and not PIC12 based PICAXE.Might work if you were so full of shit that when the defrost alarm
went off you took a dump and knew just how much shit to let go along
with the quantity of hot water required to defrost the fridge, but
you'd also have to know the heat capacity and thermal conductivity of
your poop and, ergo, how many turds to release, over time, in order to
accomplish your goal.
I suggest that you're so full of shit that you know neither.
---
We are still debating whether we should do it with a low end PIC, or
high end PIC32 just in case we need it.
---
Clue:
Generally, the strategy dictates developing the software on a platform
where you won't run out of room and, when you're done, scaling down to
what you need.
Thing is, the compressor isn't going to say to itself "Oh, the incomingOn 2011-12-13, Sylvia Else<sylvia@not.here.invalid> wrote:
the closer the inside temperature of the fridge is to the outside
temperatue the less work the compressor needs to do to circulate he
coolant.
a warm evaporator means the compressor's input is at a higner pressure
than normal and thus it needs to do less work to compress the gas
enough to condense in the condenser,
From context, I assume you meant "more" in that last sentence.
no, I means less.
It's a heat pump. and like a water pump, it uses less electricity
when pumping a smaller head.
14 degrees to 25 degrees is easier thant 4 degrees to 25 degrees.
it'll only take it a few seconds to get the temperature down to
freezing, but for a few seconds it's easier than normal.
if you let the defrosting heat escapes from the evaporator into the
contents of the fridge it's harder to call it back.
The question is - does it matter? That is, will running the compressor
when the element is warm do anything more than consume some extra
electricity.
Certainly nore "more".
---On Dec 17, 5:03 pm, John Fields <jfie...@austininstruments.com> wrote:
On Sat, 17 Dec 2011 12:15:46 -0800 (PST), linnix
m...@linnix.info-for.us> wrote:
Yes, will be there when we are ready to post the result. We are still
working on tests and evaluations.
---
You're doing nothing of the sort; you're trolling and posting
nonsense.
I always hear that, when people running out of reasoning to argue.
---A hot water heater being used to supply hot water to defrost a fridge
every time a toilet is flushed?
That part is just a joke. I guess you can't take a joke.
---Might work if you were so full of shit that when the defrost alarm
went off you took a dump and knew just how much shit to let go along
with the quantity of hot water required to defrost the fridge, but
you'd also have to know the heat capacity and thermal conductivity of
your poop and, ergo, how many turds to release, over time, in order to
accomplish your goal.
I suggest that you're so full of shit that you know neither.
---
We are still debating whether we should do it with a low end PIC, or
high end PIC32 just in case we need it.
---
Clue:
Generally, the strategy dictates developing the software on a platform
where you won't run out of room and, when you're done, scaling down to
what you need.
---
Yes, that why we should start with PIC32 and not PIC12 based PICAXE.
So, you agree that PICAXE is useless here, right?
---Why bother with low end chip and end up with problems later on.
On 15/12/2011 11:07 PM, Jasen Betts wrote:
On 2011-12-13, Sylvia Else<syl...@not.here.invalid> wrote:
the closer the inside temperature of the fridge is to the outside
temperatue the less work the compressor needs to do to circulate he
coolant.
a warm evaporator means the compressor's input is at a higner pressure
than normal and thus it needs to do less work to compress the gas
enough to condense in the condenser,
From context, I assume you meant "more" in that last sentence.
no, I means less.
It's a heat pump. and like a water pump, it uses less electricity
when pumping a smaller head.
14 degrees to 25 degrees is easier thant 4 degrees to 25 degrees.
it'll only take it a few seconds to get the temperature down to
freezing, but for a few seconds it's easier than normal.
if you let the defrosting heat escapes from the evaporator into the
contents of the fridge it's harder to call it back.
The question is - does it matter? That is, will running the compressor
when the element is warm do anything more than consume some extra
electricity.
Certainly nore "more".
Thing is, the compressor isn't going to say to itself "Oh, the incoming
gas is closer to ambient temperature, so reducing it by x degrees
requires less work.... I can relax for a bit then."
The compressor will run at its design power, and will generate a certain
amount of heat within itself, both as a result of the compressed gas
being warmer, and as a result of various inherent inefficiences. This
will raise its temperature. But if the incoming gas is warm, then that
will contribute to an even higher temperature in the compressor. There
is presumably a limit to how hot the compressor can run without damage,
and hence the question of whether it is safe to run it when the element
is warm.
Sylvia.
Sorry - induction.On Dec 19, 9:54 am, Sylvia Else <syl...@not.here.invalid> wrote:
On 15/12/2011 11:07 PM, Jasen Betts wrote:
On 2011-12-13, Sylvia Else<syl...@not.here.invalid> wrote:
the closer the inside temperature of the fridge is to the outside
temperatue the less work the compressor needs to do to circulate he
coolant.
a warm evaporator means the compressor's input is at a higner pressure
than normal and thus it needs to do less work to compress the gas
enough to condense in the condenser,
From context, I assume you meant "more" in that last sentence..
no, I means less.
It's a heat pump. and like a water pump, it uses less electricity
when pumping a smaller head.
14 degrees to 25 degrees is easier thant 4 degrees to 25 degrees.
it'll only take it a few seconds to get the temperature down to
freezing, but for a few seconds it's easier than normal.
if you let the defrosting heat escapes from the evaporator into the
contents of the fridge it's harder to call it back.
The question is - does it matter? That is, will running the compressor
when the element is warm do anything more than consume some extra
electricity.
Certainly nore "more".
Thing is, the compressor isn't going to say to itself "Oh, the incoming
gas is closer to ambient temperature, so reducing it by x degrees
requires less work.... I can relax for a bit then."
The compressor will run at its design power, and will generate a certain
amount of heat within itself, both as a result of the compressed gas
being warmer, and as a result of various inherent inefficiences. This
will raise its temperature. But if the incoming gas is warm, then that
will contribute to an even higher temperature in the compressor. There
is presumably a limit to how hot the compressor can run without damage,
and hence the question of whether it is safe to run it when the element
is warm.
Sylvia.
What sort of motor is used in a typical domestic compressor ? The
large commercial ones used 3 phase squirrel cage motors, but no idea
about domestic units, as they are sealed.
http://www.alibaba.com/product-gs/226416215/Hermetic_refrigerator_com...
This site shows what looks like a shaded pole motor at the bottom of
the compressor.
But when the input to the compressor is at a higher pressure thenOn 2011-12-13, Sylvia Else <syl...@not.here.invalid> wrote:
the closer the inside temperature of the fridge is to the outside
temperatue the less work the compressor needs to do to circulate he
coolant.
a warm evaporator means the compressor's input is at a higner pressure
than normal and thus it needs to do less work to compress the gas
enough to condense in the condenser,
 From context, I assume you meant "more" in that last sentence.
no, I means less.
It's a heat pump. Â and like a water pump, it uses less electricity
when pumping a smaller head.
14 degrees to 25 degrees is easier thant 4 degrees to 25 degrees.
it'll only take it a few seconds to get the temperature down to
freezing, but for a few seconds it's easier than normal.
if you let the defrosting heat escapes from the evaporator into the
contents of the fridge it's harder to call it back.
The question is - does it matter? That is, will running the compressor
when the element is warm do anything more than consume some extra
electricity.
Certainly nore "more".
--
ââ 100% natural
--- Posted via news://freenews.netfront.net/ - Complaints to n...@netfront.net ---
The connections go to the back of the CPU boardOn Sun, 18 Dec 2011 08:04:39 -0800 (PST), linnix
m...@linnix.info-for.us> wrote:
On Dec 17, 5:03 pm, John Fields <jfie...@austininstruments.com> wrote:
On Sat, 17 Dec 2011 12:15:46 -0800 (PST), linnix
m...@linnix.info-for.us> wrote:
Yes, will be there when we are ready to post the result. We are still
working on tests and evaluations.
---
You're doing nothing of the sort; you're trolling and posting
nonsense.
I always hear that, when people running out of reasoning to argue.
---
Well, when reason fails and all you post is nonsense, like 14 LEDs,
PCBs with connections that go nowhere,
There are additional headers on the PIC32 CPU board for buttons.and a slew of pushbuttons for data entry,
home insurance policy along those lines.In such socialist societies as Australia (and coming soon to the US),
you'd better use the exact replacement and have it done by a certified
technician... otherwise no insurance coverage at all.
Something of an urban myth, I suspect. Certainly there's nothing in my
Not if you follow proper electrical codes and with constructionwww.sa.gov.au/
Never do work on electrical installations or appliances yourself, always use a licensed electrician. Unlicensed work is illegal and extremely dangerous.
Do i have to pay for the plane ticket from Austria to California?Licensed electrical contractors have the equipment and knowledge to safely do electrical work.
When using a tradesperson for any electrical work you should ensure:
they hold an appropriate South Australian license
That means nothing to me. I just need the local city permit.they issue you an electrical certificate of compliance.
I always do my own wiring, and I usually do it hot.www.sa.gov.au/
Never do work on electrical installations or appliances yourself, always use a licensed electrician. Unlicensed work is illegal and extremely dangerous.
Do you have them change the batteries in your flashlight, too?Licensed electrical contractors have the equipment and knowledge to safely do electrical work.
When using a tradesperson for any electrical work you should ensure:
they hold an appropriate South Australian license
they issue you an electrical certificate of compliance.
This applies to all electrical work on your property regardless of whether it is your home, rental property, commercial premises, caravan or boat.