Water heater element question

[ajdelange]

Is there a cheaper way to build one of these controllers with a potentiometer or rheostat or something? I'm not an electrician however my father in law is so I'm sure he could help me put something together.

Possibly but I don't think that price is too bad for what you get. You ought to be able to get a pair of suitable thyristors for around $40 (the pair). Then you'd need heat sinks for those, a circuit to trigger them, power connectors, a box to mount the stuff in. The heat sinks are the only items, other than the thyristors, which migh cost more than a few dollars. The control circuit should be pretty simple to put together for $10 - 15 if you are willing to use proptyping "perfboard" as opposed to having a printed circuit made. You would use a potentiometer to adjust the power output by changing the firing angle of the thyristors and have virtually infinite control from fully off to fully on. Adding up all these parts you are not that far from what the manufacturer wants for what is doubtless just what I described or very close to it. For the delta $ I'd be happy to let someone else worry about the design, fab, test and safety. I'm an electrical engineer who used to design circuits like this (years and years ago) and if I'm saying it's more trouble than you'd save then I assume that goes in spades for you who apparently have no experience with this type of equipment. An electrician can help you keep from burning the house down but will not have the eperience with SCR's, diacs, triacs,... needed to put together such a system.

Another option is a variable auto transformer (Variac) if you happen to be fortunate enough to find one (Ebay or somesuch) with the current and voltage rating you need. These are kind of rare birds these days (having been replaced by the much lighter, much less expensive, thyristor based controllers).

An extremely clever scheme from a fellow named Ken Schwarz, put a simple diode in one of the power lines to the heating element with a switch across it. With the switch closed (shorting out the diode) the heater produces full power. With the switch open the diode only conducts when the voltage across it is positive (half the time) and the power is reduced to 50% of full.

[foomench]

Payne Engineering 18D-2-30i Power Controller, 240V, single phase, 30A, phase angle power control with manual potentiometer control. Another company that makes these is Clark Power Systems. Then there are a bunch of companies that make them in a higher price range, although you can find them used on eBay for a lot less. I got tired of searching eBay for one that met my specs and decided to just buy exactly what I wanted.



I bought a 5500W ultra low density incoloy heating element at my big box retailer. I considered just a 4500W, but this was the same price and fits in the keggle. I figured since I spent all the money on the controller, more power means quicker to come to a boil and I can still fine tune it down. I'm going to seal the heating element after I connect it to one of those plugs with Alumilite. I haven't yet decided if I'm going to ground to the heating element (I've done this before by tapping a screw into the body), or try to ground to the keggle somehow in the bottom skirt.

Not fully done yet--I'm working on my new HLT this weekend, but that's a different thread.

[Pharmbrewer]

Thanks all for the replys.

Sounds like That contoller really is worth the money. I'm in a tough spot where I want to but the peices for my "dream system" now instead of settleing for what works for now (ie an electric turkey fryer). Yet I can't quite afford it yet. Maybe I'll buy the kettle now with the 3500 watt element and "plug, unplug" it untill I can aford the controller and then upgrade to the 4500 Watt controller.

Thanks again everyone!
PB

[andy77]

Thanks all for the replys.

Sounds like That contoller really is worth the money. I'm in a tough spot where I want to but the peices for my "dream system" now instead of settleing for what works for now (ie an electric turkey fryer). Yet I can't quite afford it yet. Maybe I'll buy the kettle now with the 3500 watt element and "plug, unplug" it untill I can aford the controller and then upgrade to the 4500 Watt controller.

Thanks again everyone!
PB

I was glad someone beat me to this recommendation. You can find controllers cheap, and they'll provide you "set it and forget it" control. Totally worth the money.

[Nyakavt]

Are you guys using 220V GFCI breakers? Where can you find them cheap? Every time I've looked a big box hardware store they were >$100.

[foomench]

I think I've seen them online as cheap as $70, but they aren't cheap. Here's something for $62, but I'm not sure I believe that's exactly what we want: http://www.coleparmer.com/catalog/produ ... 02400&pfx=
Here's a 50 amp (more than I need) wall mount one for $80:
http://www.1800pools.com/6895_BLK_Black ... _240V.html
http://spapartsshop.com/6895-BLK.aspx
Maybe this, for $58:
http://www.poolsupplyworld.com/spagfci/ ... id=GN30638

[Pharmbrewer]

Are you guys using 220V GFCI breakers? Where can you find them cheap? Every time I've looked a big box hardware store they were >$100.

Come to think of it I may not be. I don't recall the breaker I bought being that expensive. Probably not a big issue for its current use of an electric stove, however if I make this switch I'll definately need one.

Argggghh another expense.

[beltbuckle]

Are you guys using 220V GFCI breakers? Where can you find them cheap? Every time I've looked a big box hardware store they were >$100.

Yes, and yes they are expensive. No way around it. Good news is by going electric you'll make your money back within a year or so.

I calculated how much in electricity my last (all electric) brew session cost, with a 90 minute boil. Ended up being about $1.20. Now granted we have cheap power at $0.06/kWh but still. And no lugging damn propane bottles.