Almost off the shelf AC trigger relay

I just started using this relay truck to trigger my AC unit. It has a 12 amp max and I’m using a 5 V USB to trigger.

Has anyone else found another solution to this problem?

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This looks great. Better than building one and wondering if you did it right.

I want to maybe use this for a Toshiba that runs at 11.5A. But I’m worried that start up amperage can be up to 3 times that or when compressor kicks on. Thoughts?

Also can you show how you wired up the 5v USB plug that you ran to the NIWA?

I’m also slightly confused about the inputs. Specifically, the normally on, always on, manually on.

I want to grab this but want to be sure this is the easiest and best option before trying to build one. Thanks!

First 11.5 amps is still too much for this no more than 80% of the rating. That said it works great for both my ac and 190pt dehumidifier (one per unit).

The simplest way is to buy this:

ELNONE 1 Pack 2pcs 0.3M/1 Feet 20AWG USB 2.0 Cable USB Male 2pin Wire DIY Pigtail Cable 5V 5A Black USB Plug Power Cable (1) https://a.co/d/hsAZbDC

Right on. Thanks.

What ac are you running?


The price for the IoT Relay is pretty good. The price for the RPC20 is too much for my taste, but sure it works. I built two of my own relay devices, one for my lights and one for my A/C unit with parts from Amazon and Home Depot.

2 of these for the actual contactor (relay): https://www.amazon.com/gp/product/B088895GBY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

2 of these housings: https://www.homedepot.com/p/Commercial-Electric-2-Gang-Extra-Duty-Horizontal-Vertical-Non-Metallic-Weatherproof-In-Use-Cover-73-in-1-Configurations-Gray-WCW2PG/300849087

2 of these heavy duty extension cord 15A: https://www.homedepot.com/p/HDX-9-ft-14-3-15-Amp-Air-Conditioner-Appliance-Extension-Cord-Grey-HD-277-738/100672802

and 2 of these low amp cheap ext cords for the trigger wire from NIWA: https://www.homedepot.com/p/HDX-8-ft-16-3-Light-Duty-Indoor-Outdoor-Extension-Cord-Black-EXB-1638/320258187

Total cost about $63 for each relay. I mounted them on a “control panel” board:

I soldered, shrink wrapped and taped all terminals and connections. One heavy ext cord is used for the hi amp current and the male end of one light duty ext cord for the trigger wire coming from the NIWA. These work like a charm and are used to handling hi amp loads for home central A/C units. Another brother on this forum gave me the idea and parts list, but I can’t seem to locate him again to give credit…

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