arduino etc. driven household power

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Sep 4, 2020, 12:56:55 PM9/4/20
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I am working on a project to drive a 110v, ~1000w dehumidifier and some fans with a microcontroller, Arduino or ESP8266 for example.

Any recommendations, pro or con?

I'd like to use solid state, but mechanical relays are a lot less expensive.

Are these any good?

Shawn Wilson

Sep 4, 2020, 2:58:30 PM9/4/20
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No expert, but I have an outlet wired to an Arduino, of you want to test it. Mech relay.


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Sep 4, 2020, 7:14:49 PM9/4/20
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Be sure to keep in mind that your starting current of the dehumidifier is 2-2.5 times higher then the running current. So you would overload a 10A relay significantly. 
I would spend the 15$ on top for the solid state relay so you don’t have to worry about melting relays. I use this one with a 120V/9.6A motor with no problems. 
All that said with 10A running current you are in easy electrical fire territory if wire sizes and connectors are not chosen right. So build for safety first and functionality/price second.

Sep 21, 2020, 8:22:22 PM9/21/20
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Thanks for the advice, Janosch. I purchased solid state relays like you showed. Hopefully they will (safely) do the job.

Téa Chen

Sep 22, 2020, 5:42:00 PM9/22/20
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Probably a bit late (but never sorry), but a con to the SSR would be the heat.  Your dehumidifier is likely to be run unattended for more than a few mins.  Definately get a heatsink (and enclosure fan?) and a thermal fuse.

Sep 22, 2020, 5:50:49 PM9/22/20
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Yup, I have a big heat sink in the plan. Thanks Téa.

Dec 15, 2020, 6:51:14 PM12/15/20
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Following up, now that this project is done. I made a quick-and-dirty instructable:

The mains powered devices were actually humidifiers, not dehumidifiers. So no big deal on power. I used remote switches, namely two Sonoff Basic smart switches flashed with Tasmota.

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