Wiring in line booster fan

[Cpeters]

I'm putting in a booster fan and need a way to trigger it when the ac comes on. It's a carrier FX4D used only for cooling. Someone suggested a Suncoast temp sensor and plugging in to that. Couldn't I also connect into
a taco switch relay TACO SR501 and trigger it from the 24volt thermostat. Are there relays for this purpose or
am I overthinking this? Thanks in advance.

 

[Stuff]

SR501 is overkill for this. You are correct in using 24v from the thermostat. Easier is normally to tap the G and C wires at the air handler but you can get them at the thermostat if there is a C wire there. Then drive a relay such as https://www.amazon.com/Functional-Devices-Ribu1C-Relay-Enclosed/dp/B000LESCI2 . Mount the relay at the fan junction box so you only have to run low voltage wires for any distance.

 

[Sponsor]

 

[Jadnashua]

You could use a vane/sail switch to trigger it on. It would be best if it controlled a relay. When the switch saw air flow, it would close, that would trigger a relay to apply power to the fan. There's more than one way to do this, and some of it would depend on where the motor was in relation to the air handler, how easy it is to run wiring, and the availability of power in the region.

 

[Cpeters]

Thanks for the help. I ordered the relay.

 

[Cpeters]

Thanks.

 

[Cpeters]

SR501 is overkill for this. You are correct in using 24v from the thermostat. Easier is normally to tap the G and C wires at the air handler but you can get them at the thermostat if there is a C wire there. Then drive a relay such as https://www.amazon.com/Functional-Devices-Ribu1C-Relay-Enclosed/dp/B000LESCI2 . Mount the relay at the fan junction box so you only have to run low voltage wires for any distance.

FYI,
it took a day and a half to get RIB(Relay in a Box)
It works like a champ.

the white/yellow to the common 24v
the white/blue to the fan activator on thermostat(G)
The solid yellow to the 120 line
The solid orange to the hot side of fan.
Fan ground to line ground
fan neutral to line neutral.
The solid blue and Black/white capped off

Thanks for your help.

 

[Fitter30]

A curent sensing relay would of worked also