Switching 10+ amp 120VAC loads - what am I missing?

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Hello,

My PAC/PLC experience is incredibly limited to one machine we have at work. I’m a geek though and have wanted to use a PAC system in my home shop to control all sorts of things: exterior lights, well pumps, heaters, etc. All high volt (i.e. 120 or 240 single phase), 10amp and higher circuits. I’ve reviewed the SNAP IO modules and don’t see any appropriate modules for switching these types of loads.
This makes me think I’m missing a piece of the puzzle or the solution. I’ve thought maybe contactors would be an appropriate solution, but their cost is high enough that it seems unlikely designers would use them for common use cases like controlling lighting circuits. Solid state relays are another possibility that may be appropriate.

My question to the community is: If you wanted to use a SNAP/PAC to control the type of loads I’ve described without spending a fortune on additional equipment, what approach would you take?

I hope my post isn’t too general, I tried to avoid getting too specific about a given circuit or load because I’m not quite sure what all my use cases are yet. I just know that I generally want to automate my shop and want to use SNAP to do it.
BTW, I’m focused on SNAP because for a hobby/home project I can’t afford a GROOV system, even though it would be awesome.

Regards,
Steve

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I would use a two fold approach.
For anything under 6 amps; SNAP Mechanical Power Relay Modules
For anything over 6 amps; Opto22 - Solid State Relays

The whole point of a PAC is to provide both isolation and intelligence at the edge.
Interposing relays are a thing in the real world.
To switch big loads, you use big switches.

@philip what do you use to switch 10 amps loads?

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< 10 amps typically is a relay. Contactors for higher amperage. Mostly 24VAC and 120VAC pilot signaling using OAC5 modules to switch the coil.

Usually the equipment we control already has the relay/contactor as part of the equipment. We don’t see too much of solid state power relays other than on modulating duct toasters.

One word of caution, especially when having fun with stuff like this at home - ask yourself who will service/maintain it if you were gone.

1 Like
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For a home project, and for loads between 6 and 16amp, one could use this from Amazon ($46.50 for 4-circuit model):

DIN Rail Mount AC/DC 24V control 4 SPDT 16Amp Pluggable Power Relay Module, G2R-1-E
[Amazon.com]