Before I start my controller build, here is the setup i'm planning.
Essentially i'd like to control two 1500 watt 120V elements, thus I can use the full 3000 watts of heat up, and then load balance the operating wattage across both elements for the output phase of the run; ergo two parallel independent circuits.
Excluded from the diagram are grounding connections between SSR heatsinks, pots, input leads and output leads.
Do yourself a favor. Wire one element to the controller, and plug the other one directly in. Unplug the one when you get to temp and run off the other. Much simpler.
Hi MK, Much appreciated for giving it a look over.
A question please, was your recommendation to go with a single controller pointed towards the cost of going double, or perhaps the complexity?
I had thought that by spreading the load over two controllers I could reduce the likely hood of scorching, and the overall stress on the two supply curcuits... 6.5A per circuit rather than 13A on a single.
If you have controllers on both you have to worry about adjusting both. But you still get the full range of adjustability with one full power and one adjustable.
Lets say 1500W for both, giving you a total of 3000W. If you want it at anything above 1500 you turn on the full power one and adjust the other to get your desired power input. If you want below 1500 then unplug the full power one and just use the adjustable. Simpler than trying to play with 2, cheaper too I'd think.
ExpatLad wrote:Hi MK, Much appreciated for giving it a look over.
A question please, was your recommendation to go with a single controller pointed towards the cost of going double, or perhaps the complexity?
I had thought that by spreading the load over two controllers I could reduce the likely hood of scorching, and the overall stress on the two supply curcuits... 6.5A per circuit rather than 13A on a single.
Thank you again for having a look!
A typical 120 volt household electrical circuit is on a 15 amp breaker and should be loaded about 80% which is about 12 amps. If you have a 20 amp breaker then you could do about 16 amps. I like the two element approach but I would make only one of them adjustable.
Sam, Regarding ULD elements, there isn't much in the way of these in the 120V category (aside from running a 240V elements at 120) there isn't anything I can do there.
Ron, Angel, I understand, so as I described in the schema I'll be using standard 15A circuits; so running them at 13A (87% of max) is workable but would seem (at least to me) to pushing it. From what I know about other non-wiring workload applications, its generally advisable not to run equipment at max or near max for extended periods; not sure if that applies directly to this, but its the basic premise I was working under. No
Running 2 controllers is pointless. 2 at 750 watts is still 1500 watts of energy going in. Yes the watt density is lower but ULWD elements are readily found with a bit of looking.
Running 2 controllers is pointless. 2 at 750 watts is still 1500 watts of energy going in. Yes the watt density is lower but ULWD elements are readily found with a bit of looking.
BB, that element you're pointing to with your link isn't what is actually shipped. I ordered one of these a couple weeks ago and received a package labeled with the 02853 model number, but contained an element with a different model number (02852) stamped on it. It isn't by any means the same element as described in the Amazon description. I found a brewer forum discussion online which indicated that several other folks had experienced the same problem. I had to ship it back for a refund.
You would probably be better off buying a couple of fold-back type 5500w 220v elements and running them on 120v. At 1375w, you're only loosing 125w per element. I found one at Lowe's that is 11" long which fits my 12" diameter stock pot very well. With the fold-back, the element has about 18 inches total heating surface, which I think probably makes it ULWD when used at 120v.
Just sayin',
S-C
Edit - I notice in the Amazon description that they have changed the description to read, "02852/02853" - probably after many complaints. This doesn't change the fact that they are two totally different elements. The fold-back on the 02852 is only about 1" long. Compare THAT to the picture associated with the ad. No way the 02852 is ULWD.
Every new member should read this before doing anything else:
Hey Expatlad. I was looking the first time on my phone and didn't see the 15A at the bottom. A load of 87% would probably work OK as long as this is the only thing on the circuit. One of the major problems is that for continuious use the breaker will begin to heat up and at some point may trip even if it is not overloaded. Be aware of what other devices are on the same circuit such as lights and especially an appliances. Also if it is an old breaker it will trip easier than a new one.
Whatever you decide to do since you will be running continuously for hours and if you are running above 80% load I would suggest that you changeout the old breaker for a new one unless you know it is relatively new.
