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Power controller for elements

PostPosted: Tue Oct 07, 2014 8:05 pm
by Shiftynev
Hi guys,
Thinking of buying one or two of these to control heating elements (2400w, one for each) ,http://www.ebay.com.au/itm/4000W-AC220V-SCR-Electric-Voltage-Regulator-speed-controller-light-dimmer-/301307538639?pt=LH_DefaultDomain_15&hash=item4627542ccf/ which is on ebay. Wondering if anyone has used these and if so, any thoughts. Have seen some which are cheaper but they don't come in metal box. Dont know much about electricity (and many other thing) and was wondering if this 220vunit will work in Australia which has a 240v supply. Would appreciate any advice, thoughts etc.

Cheers

Re: Power controller for elements

PostPosted: Tue Oct 07, 2014 9:45 pm
by woodduck
Hey shifty,
I bought a few of these and they seem to work ok. I had one on my other keg and it didn't miss a beat. I don't know how a little thing like that can take the power but it does. Others may have other experiences but hey for $7 i thought it was worth a try.


http://www.ebay.com.au/itm/0-220V-3800W ... 1c220204f6

Anyway good luck

Re: Power controller for elements

PostPosted: Tue Oct 07, 2014 10:08 pm
by Shiftynev
Thanks Wood,

I'll order a couple, get a metal box from Jaycar as well as a voltmeter and see a sparky mate about putting it together.

Cheers

Re: Power controller for elements

PostPosted: Tue Oct 07, 2014 10:14 pm
by woodduck
I don't know about a metal box? Plastic would be better i recon.

I don't want to talk you in to anything, this was just my experience, i can't garentee them but hope they go ok for ya.

Re: Power controller for elements

PostPosted: Tue Oct 07, 2014 11:43 pm
by Shiftynev
Only said metal because I assumed that the one you used was metal. Not really that big an issue. I assumed metal for grounding. I think I'll talk to my mate before or better still let him buy what's needed. Appreciate your advice and information and at the end of the day the cost is minimal so as they say, " nothing ventured nothing gained".

Re: Power controller for elements

PostPosted: Wed Oct 08, 2014 3:47 pm
by peterhobit
Shiftynev, when I look at the one in your link and scroll down to the bottom of the page there is one from eachbuyer for $9.53

Re: Power controller for elements

PostPosted: Wed Oct 08, 2014 7:55 pm
by Shiftynev
Thanks Pete, you've got a good eye mate. Cheers

Re: Power controller for elements

PostPosted: Wed Oct 22, 2014 5:34 am
by Anthoney
An ammeter on the input side will be a better, linear, guide to the power being used than a voltmeter on the output.
With the voltmeter half volts is not half power. It is a non linear relationship. With input amps half amps means half power. It is a linear relationship.

Re: Power controller for elements

PostPosted: Sun Mar 15, 2015 9:29 am
by phonetic
Power is proportional to the square of the current or voltage. eg:
P = I^2R
P = (V^2)/R

Re: Power controller for elements

PostPosted: Sun Mar 15, 2015 12:00 pm
by Mad
http://pages.ebay.com/link/?nav=item.view&id=251609046730&alt=web


I have one of these on the way should do the trick

Re: Power controller for elements

PostPosted: Sun Mar 22, 2015 7:48 pm
by Hari
Hi Shifty Nev.
Just a word of caution guys, get your Australian electrician to look at these before you buy one. I dont think they have an earth terminal and do not comply with Australian standards. If they do thats great, I will then get one.

Please let us know what your sparky mate has to say.
regards
Hari.

Re: Power controller for elements

PostPosted: Sun Mar 22, 2015 7:55 pm
by 1 2many
Hari wrote:Hi Shifty Nev.
Just a word of caution guys, get your Australian electrician to look at these before you buy one. I dont think they have an earth terminal and do not comply with Australian standards. If they do thats great, I will then get one.

Please let us know what your sparky mate has to say.
regards
Hari.


Yeah they do have an earth point on the metal case far left hard to see in the pic.

As for complying with Australian standards I doubt very much.

Re: Power controller for elements

PostPosted: Sun Mar 22, 2015 8:47 pm
by Triangle
They're designed as a chassis or similar mount where the earth is achieved through the chassis and by earth bonding to this unit frame itself. Anything else is asking for trouble :scared-eek:

Re: Power controller for elements

PostPosted: Mon Mar 23, 2015 4:54 pm
by 1 2many
Triangle Going Sick wrote:They're designed as a chassis or similar mount where the earth is achieved through the chassis and by earth bonding to this unit frame itself. Anything else is asking for trouble :scared-eek:


Correct, but i don't get what you mean by "Anything else is asking for trouble" :think:

Care to elaborate.

Edit: I think I figured it out, the earth screw I mentioned might not be up to the standard required to handle the current should the device fail.

Re: Power controller for elements

PostPosted: Mon Mar 23, 2015 7:55 pm
by Triangle
1 2many wrote:
Triangle Going Sick wrote:They're designed as a chassis or similar mount where the earth is achieved through the chassis and by earth bonding to this unit frame itself. Anything else is asking for trouble :scared-eek:


Correct, but i don't get what you mean by "Anything else is asking for trouble" :think:

Care to elaborate.

Edit: I think I figured it out, the earth screw I mentioned might not be up to the standard required to handle the current should the device fail.


Yep, sorry I was thinking if someone decided to mount that unit inside a plastic box to create double insulation and not worry about the earth, the pot shaft would still be an issue. If like you mention it is in fact earthed but not correctly or well enough and there is a ground fault then the protective device will not trip and there becomes a potential difference between the steel frame and earth possibly above what is safe.

Re: Power controller for elements

PostPosted: Tue Mar 24, 2015 3:33 pm
by 1 2many
This is the earth terminal I referred to before, I can't see why it couldn't be used.

I would rather that then no earth.


rsz_20150324_162754.jpg

Re: Power controller for elements

PostPosted: Tue Mar 24, 2015 4:51 pm
by Meatheadinc
1 2many wrote:This is the earth terminal I referred to before, I can't see why it couldn't be used.I would rather that then no earth.

:text-+1:

anywhere there is a solid connection will do.....

Re: Power controller for elements

PostPosted: Tue Mar 24, 2015 9:28 pm
by Triangle
:handgestures-thumbupleft:

Looks fine. I'd assumed from previous posts there was no provision for an earth. All good.

Re: Power controller for elements

PostPosted: Thu Mar 26, 2015 5:45 am
by Mad
Mine just arrived last week. Have been busy with other things to post but wired it up ran it and an hour into the run it had a catastrophic failure of the enth degree lol. Glad i had earthed it and was on an rcd. I had the 4000w rating and run a 3600w element - safe to say it overheated. They are resending a new one but I've also bought a 10000w

Re: Power controller for elements

PostPosted: Thu Mar 26, 2015 4:04 pm
by 1 2many
Mad wrote:Mine just arrived last week. Have been busy with other things to post but wired it up ran it and an hour into the run it had a catastrophic failure of the enth degree lol. Glad i had earthed it and was on an rcd. I had the 4000w rating and run a 3600w element - safe to say it overheated. They are resending a new one but I've also bought a 10000w


Was it in an enclosed box Mad? did you have a fan on it? :-B