Electronic Controller, Dumb It Down ?

[Roy Tataver]

I am having trouble finding a simple solution for my boiler heating element. I read through the huge post on the topic, but I'm not an electrician or even very electrically savvy. I just want to buy something that will offer variable control of the heat output of my 220V hot water heating element. I have a North American stove plug in close proximity to my work area. Can someone simplify whats required to do this, Id prefer to have the fine control of the temperature setting in my boiler!

Please Help!!!

[myles]

It depends on the power of your element but there are off the shelf power controllers that will do the job. Either burst fire or phase angle controllers. Not as satisfying as building from components but just as effective.

This is an example of a 240v 6kw version but there are others out there for either 240v or 115v.

LINK:http://uk.farnell.com/united-automation ... dp/1213091

I am using a 16A burst regulator for the 1.5kw hotplate on the VM rig.

[MuleKicker]

there are a few builds in the new distiller's lounge.

[squidd]

Roy,

Two easy peasy options.

1. Mule Kicker on this site builds power controllers to order.

2. Google "acifica inc" and do a search on their site for a "variac".
Look at their Mastech 5000 VA 220 volt input unit. (It can also be used to control 110 volt loads).
It's a variable transformer, weighs 15 kilos. (Brute force approach).
Good for a 220 volt element up to 5,000 watts.
You will have to install inlet and outlet power cords; then it's Plug and Play.

No affiliations, etc.

HTH,
squidd

[Roy Tataver]

I was always thought that it was 110 or 220v in Canada. Is that correct? UK is 240v? Would i just have that wired in line with a dimmer or something? The burst controller that is! Sorry for the dumb questions but as i said, not very good with electricity, i will have a friend who is much better with it review my work before i go ahead and burn down my house!

[myles]

The burst regulator that I have is a self contained off the shelf unit. All you do is connect the suply and load cables and it is good to go. It might need to be screwed to a heat sink - depends on local conditions.

http://uk.rs-online.com/web/search/sear ... &R=2143979

[kenfyoozed]

Myles, what size element are you using?

[Roy Tataver]

Thanks for the reply, Ive been reading the build up section for the controller and have a good idea of how to build one of these things now. Took a whole day of combing over the details and a few pots of coffee. I'll be in the market for one in the spring or later this winter and i may be ordering on from Mule kicker! I priced out the parts up here in Canada and it would be roughly $150 to be up and running.

Next i need a good build on SS stock pot electric boiler!!!!

[myles]

Myles, what size element are you using?

I have a 40 Amp pinto controller that works with a 3kw element on the pot still.

This burst regulator is for a 1.5kw hotplate on a 'small keg' reflux still. It will cope with more than that so should last fine. In general you dont want to run any controller close to its maximum capacity for long.

Myles

[Kentucky shinner]

Get you one from MK,, it is built specifically for the task at hand...
KS

[bgrizzle]

+1 KS.... my 5500WMK is enroute... why re-invent the wheel?

[RyanS]

So if 4400 watts @ 240v is just over 18 amps. ie within range of Australian domestic circuits. If you turn down the voltage to say 100, = 44 amps & household fuse go kaboom?

Seriously I wouldn't settle for anything other than Rockwell Automation as I will never have a problem with inductive avalanches at breakdown voltages when attempting to vary background switching sinosoidal amperage with a 360 degree inverse potentiometer at well above the recommended thermaldynamic phase detraction variable!

http://www.youtube.com/watch?v=RXJKdh1KZ0w" onclick="window.open(this.href);return false;" rel="nofollow

[rad14701]

So if 4400 watts @ 240v is just over 18 amps. ie within range of Australian domestic circuits. If you turn down the voltage to say 100, = 44 amps & household fuse go kaboom?

Seriously I wouldn't settle for anything other than Rockwell Automation as I will never have a problem with inductive avalanches at breakdown voltages when attempting to vary background switching sinosoidal amperage with a 360 degree inverse potentiometer at well above the recommended thermaldynamic phase detraction variable!

http://www.youtube.com/watch?v=RXJKdh1KZ0w" onclick="window.open(this.href);return false;" rel="nofollow

No, it doesn't work like that at all... The amperage is dependent upon voltage and resistance... The element has a fixed resistance... Therefore varying the voltage varies the amperage... I have posted a spreadsheet in the Resources and Reviews forum which can help in understanding heating element control...

A circuit on 240V mains with a 4400W element would only draw 7.6A with the power reduced to 100V using a controller... It is your method of calculating that is flawed, causing you to come up with the inaccurate figure of 44A... It is an easy mistake to make... That is why I created the spreadsheet... The magic number is the 13.1 Ohms of fixed resistance in the element...

[myles]

Rad just in case they don't follow the reasoning, it works like this.

4.4kw element rated @ 240v.
P = I x V so 4400 = I x 240 I = 18.3A
V = I x R so 240 = 18.3 x R element resistance = 13.1 ohms

Using that same element on 100v gives
240 = I x 13.1 I = 7.6A

When you use a controller you change both the voltage AND the current. I keep stressing this because it does help.

ALWAYS calibrate your controller. Measure current and voltage over the range of the pot, so that you can duplicate your results from run to run. If you change element do it again, because it will be different.

[rad14701]

You're right, myles... I just left out the ugly math that just gets folks confused...

I'm a long drawn out equation kinda guy myself... Never been one for cryptic engineering formulas... Probably stems from too many years of having to write formulas that simple computers can understand...

Remember, he said "Dumb it down", which is what the spreadhseet does...