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Some background, I was recently helping a friend who had their indoor and outdoor system replaced before winter who said the system was no longer functioning. From what I can tell, their family friend put a 10KW electric heater kit on a 30A breaker, and this kicks the breaker pretty quickly when you have the heat on. It looks like the previous unit had a reversible heat pump outside and much smaller electric heater in the indoor unit, however this system has no reversible heat pump and a large electric heater.

This heating kit has two coils, each on their own sequencer. Each circuit has its own heat cutoff safety, but the trigger wires are tied together as it's a single stage heater kit. Is it safe to disconnect the trigger wires to one of the sequencers to only run one heating coil, effectively making it a 5KW heater? Are there any gotchas that I might be overlooking here?

Here's a picture identical to the kit installed in this HVAC unit. The stacked sequencers are also single stage, so both wires go active at the same time.

RHEEM Heating kit

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  • What's with the floating circuit breaker and all the wires coming out of it? What are the extra wires dangling off to the left of the breaker for? How is yours actually wired? I think if you can remove one internal wire from both ends, and remove it completely so you don't have to worry about loose dangling wires inside the unit, that should address any gotchas. A schematic of the heater would help to be sure.
    – jay613
    Feb 1, 2022 at 16:40
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    If the coils are in parallel pull the control wire off of the relay /contactor this will cut the load without hacking things. Some relays are labeled A1-A2 for the control and they are smaller wires. Put some tape on the female spade connector / some call a disconnect. In this case I would pull the white wire as it should be a neutral or common so it may be less hazardous this way.
    – Ed Beal
    Feb 1, 2022 at 20:54
  • @EdBeal Yep, coils are in parallel. It's using sequencers as relays (I assume so there's a small delay between the blower kicking on and the heating strips kicking on). The two control wires go to the top and bottom of the first sequencer, then have a small 3 inch wire hop from one sequencer to the other one. My plan was just to remove those small control wires to the second sequencer.
    – Food
    Feb 2, 2022 at 20:59
  • @jay613 some AC units use an internal circuit breaker as circuit protection and as a service disconnect. This unit uses a removable sort of spade key as a service disconnect. In both cases the input 240V comes through it. Sorry for the lack of diagram. I literally cannot find any information on HVAC parts online, let alone diagrams. The coils are in parallel, each has their own sequencer as a relay that both sides of the 240V input run through for each coil, with the control wires tied together. Control wires come from the board (so thermostat white goes through the control board).
    – Food
    Feb 2, 2022 at 21:05

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With the coils in parallel it will be safer to run one than tripping the breaker (over loading the circuit) , if this provides enough heat in the future if the coil fails you have a backup. Make sure to make notes with a sharpie on what you do so in the future it can be reversed if a larger feeder is installed.

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