I have seen where some people use two SSR's per heating element and some don't. Not being a electrical engineer, I tend to fall on the side of using 2. Seems like if one was good enough for 220, they wouldn't sell 2 pole switches?
When I ordered parts I was only thinking one per heating element. I got 2 40 amp ssr's and 2 25 amp ones for the pumps.
Two fold question.
Should I get two more, or just go with what I have and only switch one side of the element?
If I get two more, since the heating elements are 4500 watt (maybe down the road 5500 watt) do I just get 2 more 25s and use them on the elements, and the 40's on the pumps, or get 2 more 40's and keep the 25's on the pump?
Thanks in advance.
SSR's for Heating Elements
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JonW
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Re: SSR's for Heating Elements
The reason for 1 vs 2 is whether it is running on 110 or 220. In 110, you are only switching 1 hot leg of the power, in 220, you are switching 2 hot legs.
Use the 25 Amp SSR's for the pumps, they'll only pull a couple of amps. You need the 40's on the heating elements (with heat sinks).
Use the 25 Amp SSR's for the pumps, they'll only pull a couple of amps. You need the 40's on the heating elements (with heat sinks).
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clearwaterbrewer
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Re: SSR's for Heating Elements
I believe it is perfectly acceptable to only use a single SSR and leave the other side hot, that is how the water heater elements operate in normal life in you water heater... In addition,l most folks have (all should have) an e-stop that runs a contactor for all the 120/240V, and if the contactor is off, the element is not live.
That being said, I have 2 SSR's per element, as it fixes a couple issues...
If an SSR stuck on, the other one would stop the element from firing.
If you wanted a panel/switch indicator on the SSR output, it would have to be 240V and across both legs, as the switched side of the SSR is going to float hot.
That being said, I have 2 SSR's per element, as it fixes a couple issues...
If an SSR stuck on, the other one would stop the element from firing.
If you wanted a panel/switch indicator on the SSR output, it would have to be 240V and across both legs, as the switched side of the SSR is going to float hot.