Electric Furnace

[dnbob]

We are wiring a furnace with a 24 KW 208 single phase heat strip, and a separate 20 amp 208 volt circuit for the blower motor. The heat strip is not connected to the blower motor/circuit board.

Will I have to install a disconnect within sight for the electric heat strip at the furnace, along with a separate 20 amp disconnect for the blower/board, grouped per 424.19?

I haven't wired one for a while, but thought we used to be able to use a lockoff for the electric heat portion, but I don't see that as an option for this install.

 

[texie]

We are wiring a furnace with a 24 KW 208 single phase heat strip, and a separate 20 amp 208 volt circuit for the blower motor. The heat strip is not connected to the blower motor/circuit board.

Will I have to install a disconnect within sight for the electric heat strip at the furnace, along with a separate 20 amp disconnect for the blower/board, grouped per 424.19?

I haven't wired one for a while, but thought we used to be able to use a lockoff for the electric heat portion, but I don't see that as an option for this install.

Did the manufacturer supply the required subdivision of the heater or do you need to furnish multiple 60 amp circuits? One circuit or multiple circuits will depend on how the heater is built and listed.

 

[GoldDigger]

We are wiring a furnace with a 24 KW 208 single phase heat strip, and a separate 20 amp 208 volt circuit for the blower motor. The heat strip is not connected to the blower motor/circuit board.

Will I have to install a disconnect within sight for the electric heat strip at the furnace, along with a separate 20 amp disconnect for the blower/board, grouped per 424.19?

I haven't wired one for a while, but thought we used to be able to use a lockoff for the electric heat portion, but I don't see that as an option for this install.

Look at 424.22 for at least partial answers to both of your questions. You do not appear to be allowed to use a single 115A+ circuit for the heat strip.
Often the blower motor feed is split off inside the unit from the feed to one of the heat strips, so that a separate breaker is not required. That certainly makes identifying the power sources easier.
Will the furnace also incorporate AC, so that the blower will regularly be used independently of the heat strips?