3 speed fan switch wiring question

[maplewood]

Not really garage related, forgive me. I'm installing a "room to room" transfer fan to send air from a closet to the next room. The closet houses a small server rack, which is proving to run slightly warmer than planned, hence the fan.

There's a dedicated 20 amp circuit to a single outlet in the closet, with 12 gauge wire back to the panel. There's a ton of overhead on this circuit, so my plan is to put a junction box in the attic and use it to power the fan, which is fairly low powered. I also have a 3 speed switch (sold with the fan) that'll go into a single gang box elsewhere on the wall.

Here's what the supplied wiring diagram looks like:


This mostly makes sense, it essentially uses the fan unit as a sort of junction box. This is all behind a 20 amp breaker, so I'd use 12 gauge NM from my junction box in the attic to the fan unit. My confusion is over the wiring from the fan to the switch. The switch has flying leads that are 18 gauge stranded wire. Should I still be using 12 gauge between the fan and switch, or something else? It's all simple enough, I just want to make sure I'm using the right wire, and the 18 gauge leads threw me for a bit of a loop, as I was planning on just getting 12/4 NM for the connections.

 

[wyliesdiesels]

yes use #12....

 

[Innovate1]

Almost always equipment has smaller wire than code requirements for power wiring to the equipment. That's the case even for equipment that draws larger currents.The equipment is covered by different rules. That does not change the required size to run to the equipment/device.

 

[maplewood]

Thanks guys. I did try to do research since I'm not an electrician, but 12 gauge to 18 gauge just kinda threw me for a loop since it's such a big difference.

I also read that you're not supposed to use multiple wires, so I have to try and find 12/4 with ground, which is apparently a bit hard locally. Really don't want to end up with an entire roll of it when I need < 20 feet and I can't think of a reason I'll need more within a few years.

 

[dave*99]

Not really garage related, forgive me. I'm installing a "room to room" transfer fan to send air from a closet to the next room. The closet houses a small server rack, which is proving to run slightly warmer than planned, hence the fan.

There's a dedicated 20 amp circuit to a single outlet in the closet, with 12 gauge wire back to the panel. There's a ton of overhead on this circuit, so my plan is to put a junction box in the attic and use it to power the fan, which is fairly low powered. I also have a 3 speed switch (sold with the fan) that'll go into a single gang box elsewhere on the wall.

Here's what the supplied wiring diagram looks like:


This mostly makes sense, it essentially uses the fan unit as a sort of junction box. This is all behind a 20 amp breaker, so I'd use 12 gauge NM from my junction box in the attic to the fan unit. My confusion is over the wiring from the fan to the switch. The switch has flying leads that are 18 gauge stranded wire. Should I still be using 12 gauge between the fan and switch, or something else? It's all simple enough, I just want to make sure I'm using the right wire, and the 18 gauge leads threw me for a bit of a loop, as I was planning on just getting 12/4 NM for the connections.

Are you mounting the 3 position switch inside the fan unit? Or in a remote box like a single gang wall box? Some Tjernlund fans have the switch controls in the fan unit and some are hardwired with remote mounted switches.

 

[PCustoms]

Are you mounting the 3 position switch inside the fan unit? Or in a remote box like a single gang wall box? Some Tjernlund fans have the switch controls in the fan unit and some are hardwired with remote mounted switches.

I also have a 3 speed switch (sold with the fan) that'll go into a single gang box elsewhere on the wall.

 

[maplewood]

Yep, as mentioned separate single gang box for the switch. Ordered some 12/4 from Wire Your Way, couldn't find any locally without buying an absurd amount of it. Unexpected delay to the project but I have at least 3 others to work on in the meantime!