control electric heat pump remotely with contactor


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Old 02-09-18, 07:14 AM
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control electric heat pump remotely with contactor

We have a vacation place with an electric heat pump for DHW that is 220V and 30 amp. I would like to control it remotely so that the water is hot when we arrive. I tend to turn off the breaker when we leave and turn it on when we arrive (sometimes we are away for several weeks), but it takes quite a while to reach temperature. I read that I could buy a 30 amp contactor and wire it between the breaker panel and the heat pump and the run a 120 v line to an outlet where I have a wemo remote plug. Then I would be able to turn heat pump on and off remotely. I just want to be sure I'm not doing anything dangerous. Thanks. Dave
 
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Old 02-09-18, 07:54 AM
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Yeah it seems that could work OK. Just make sure to use the right fittings for connecting cords to junction boxes and that your contactor is rated for the 30A motor load. This is different than a 30A resistive load so read carefully on the spec sheet.
 
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Old 02-09-18, 08:05 AM
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Do you have wifi there? I have a thermostat I can control from anyplace. I have the Iris from Lowes but there are many different ones. Pretty easy install and any problems they have a 800 number for help.
 
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Old 02-09-18, 08:13 AM
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I have the Ecobee thermostat, which we love. Works on WiFi. As far as the load, in heat pump mode, each leg of the 220 line pulls 2.5 amps. In fast recovery mode,with the heating elements going, each leg pulls 19.5 amps. I would think a 30 amp contactor would be sufficient. No?
 
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Old 02-09-18, 05:54 PM
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I read that I could buy a 30 amp contactor and wire it between the breaker panel and the heat pump and the run a 120 v line to an outlet where I have a wemo remote plug.

I have no idea what a wemo plug is, but it sounds like something you control remotely so this could work. I'd recommend a 30A 2P Definite Purpose Contactor with a 120 volt coil. I always found Grainger to be an invaluable source for these DP contactors. The last time I checked, they were selling Square D contactors.
 
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Old 02-09-18, 08:36 PM
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You may not be able to cut 240v to it...... restore it and have the unit restart.
Have you tried just turning the breaker on and the unit starts by itself ?
 
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Old 02-10-18, 06:31 AM
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You also need to check to make sure that there is no crankcase heater that needs to be constantly energized.
You would be better off just switching the control circuit rather than killing the main power.
It would also be a less expensive control relay rather than a high current contactor.
 
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Old 02-10-18, 11:40 AM
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I'm in total agreement with Greg.
If you post the model number for the water heater I can check further for you.
 
 

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