ECN Forum Forums Code Related Discussion NEC & other Code issues 14-2 switch leg on 20amp circuit

is it legal to use a 14-2 for a switch leg only on a 20 amp circuit?

NO!

It is an illegal branch circuit tap. Fixture wires are one of the few legal branch circuit taps. These are discussed in sections 402.10 and 402.11. You have a branch circuit, not fixture wires.

What about a switch that controls a motor with thermal overload protection?

Bob (Iwire) is right...this is a tough crowd! Watthead: I would agree with you on that one.

Yes the members here are on top of things.

That's good. it forces me to look things up like I should be anyway

Bob

I agree, no on the 14 AWG with the 20 amp lighting circuit.

Reminds me of a thread a while back....some adamant discussions on a tap rule for #14 from #12 (20 amp circ OCP.

That thread had a lot of action....time permitting I'll have to look for it.

#14 switch leg off of a #12 20 amp, you get a red sticker!

As to Watthead's comment, yes thats allowable, but the original ?? seemed to lean toward a resi situation.

John

when or is a #14 wire allowed on a 20 amp circuit ?

Randy,

Circuits supplying motors and air conditioning equipment.

Case in point: The AC units at my house are ultra high efficiency.

Nameplate says:
Min circuit ampacity: 11 amps.
Min fuse/breaker: 15 amps
Max fuse/breaker: 30 amps

So the feed could be #14 protected by a 30 amp breaker.

Peter

[This message has been edited by CTwireman (edited 04-02-2004).]

By Randy.

14 AWG is rated 20 amps @ 60 C & 75 C, even 25 amps @ 90 C which helps when needing to derate.

The only thing that normally keeps 14 AWG on a 15 amp breaker is 240.4(D)


Notice the first part of that says:

"Unless specifically permitted in 240.4(E) through (G)"

(E) Tap Conductors.

(F) Transformer Secondary Conductors.

(G) Overcurrent Protection for Specific Conductor Applications

(G) has a table that lists about 10 applications that may allow 14 AWG on a breaker larger than 15 amps.

As Peter (CTwireman) pointed out HVAC equipment is one of those times, so are motors.

With the following nameplate data 14 AWG would be fine on a 30 amp breaker

Nameplate says:
Min circuit ampacity: 19 amps.
Max fuse/breaker: 30 amps

Bob