Double Pole Electric Base Board with Single Pole Thermostat

[gjhayes66]

Hello All,
Is it code compliant to install a single pole thermostat on a double pole electric base board heater. If so, is any type of disconnect required? 2014 NEC.

Thank You

 

[ptonsparky]

Yes, single pole thermostats are allowed on baseboard heaters for control. The two pole circuit breaker is the disconnecting means.

 

[Dennis Alwon]

Yes but you would need a breaker lock I believe

 

[Dennis Alwon]

I believe 424.19 is the section to look at.

424.19(B) Heating Equipment Without Supplementary Overcurrent
Protection.
(1) Without Motor or with Motor Not over 1∕8 Horsepower.
For fixed electric space-heating equipment without a motor
rated over 1∕8 hp, the branch-circuit switch or circuit breaker
shall be permitted to serve as the disconnecting means where
the switch or circuit breaker is within sight from the heater or
is lockable in accordance with 110.25

 

[infinity]

Yup if the stat only breaks one leg it doesn't qualify as the disconnecting means so you'll need one within sight (can be the panel where the circuit originates) or a locking device on the breaker that's not within sight.

 

[gjhayes66]

Thanks All

 

[LarryFine]

You can also get T-stat that breaks one line for control but opens both lines when set to off. Having an off position is the indicator of a T-stat that does so.

 

[MAC702]

I've only done one line-voltage stat in recent memory. It had an off-position. It only broke one line no matter what it was doing. The other line didn't even pass through it.

 

[LarryFine]

Weird.

 

[MAC702]

I should clarify that it had an "off" position on the temperature dial, but not a separate on/off switch. It was a Honeywell. And it was rated 120/208/240/277.

 

[romex jockey]

Yup if the stat only breaks one leg it doesn't qualify as the disconnecting means so you'll need one within sight (can be the panel where the circuit originates) or a locking device on the breaker that's not within sight.

I'm curious if a locking panel door is compliant?

~RJ~

 

[Dennis Alwon]

It is much simpler to get a dp T-stat

 

[infinity]

I'm curious if a locking panel door is compliant?

~RJ~

No.

 

[romex jockey]

No.

Was this always this way? Or a recent change Infinity?

~RJ~

 

[infinity]

Was this always this way? Or a recent change Infinity?

~RJ~

Here's the 2017 section:

110.25 Lockable Disconnecting Means. If a disconnecting
means is required to be lockable open elsewhere in this Code, it
shall be capable of being locked in the open position. The
provisions for locking shall remain in place with or without the
lock installed.
Exception: Locking provisions for a cord-and-plug connection shall not
be required to remain in place without the lock installed.

Here's the 2005 section:

424.19(B) Heating Equipment Without Supplementary Overcurrent Protection
(1) Without Motor or with Motor Not Over 1 / 8 Horsepower For fixed electric space-
heating equipment without a motor rated over 1 / 8 hp, the branch-circuit switch or circuit
breaker shall be permitted to serve as the disconnecting means where the switch or circuit
breaker is within sight from the heater or is capable of being locked in the open position

 

[romex jockey]

Here's the 2017 section:



Here's the 2005 section:

Thx Infinity

I'm curious if a 'lockable panel cover' complies w/ 110.25>>>

opinions??? :bye:

~RJ~

 

[MAC702]

I would hope not. You should be able to access and turn off other circuits without violating the lock on the circuits that are already locked out.