Electric furnace circuit.

[ronball]

Can I use 8/2 Romex for a electric furnace. Min. circuit 45.6 Max OCP. 50
120/ 208 volts Have about 39 of these to run. Thx

 

[LarryFine]

Negative. You need #6 NM cable or another wiring method.

Perhaps SE cable, even #6 aluminum, will save some money.

 

[HEYDOG]

No! A #8 Romex would fall under the 60 degree C column that limits it to 40 amps.

 

[Tulsa Electrician]

Can I use 8/2 Romex for a electric furnace. Min. circuit 45.6 Max OCP. 50
120/ 208 volts Have about 39 of these to run. Thx

Just a little more information please.

 

[LarryFine]

I missed the 208v myself. It's a good point, maybe. The unit may or may not be labeled differently for 208v.

OP: Is that the unit's 240v or 208v rating? Or is there only the single MCA?

 

[Tulsa Electrician]

I missed the 208v myself. It's a good point, maybe. The unit may or may not be labeled differently for 208v.

OP: Is that the unit's 240v or 208v rating? Or is there only the single MCA?

Hoping the 120 was a typo.

Can I use 8/2 Romex for a electric furnace. Min. circuit 45.6 Max OCP. 50
120/ 208 volts Have about 39 of these to run. Thx

May need four wire cable if unit needs 120/208. I doubt that though.

Or is the system voltage 120/208
With the unit being 208v

 

[ronball]

Just a little more information please.

Will be connected to 208 volts. the hvac specs list the min . and the max.
Thx all . I thought we had to use the 60 Degree chart also.

 

[ronball]

Hoping the 120 was a typo.

May need four wire cable if unit needs 120/208. I doubt that though.

Or is the system voltage 120/208
With the unit being 208v

Sorry about that.. 208 Volts .

 

[ronball]

Just a little more information please.

208 volt connection. Thx

 

[ronball]

I missed the 208v myself. It's a good point, maybe. The unit may or may not be labeled differently for 208v.

OP: Is that the unit's 240v or 208v rating? Or is there only the single MCA?

Its the cut sheet Rating. for 208 volts

 

[Tulsa Electrician]

Will be connected to 208 volts. the hvac specs list the min . and the max.
Thx all . I thought we had to use the 60 Degree chart also.

Your welcome and thank you for the additional information.

As LarryFine said in Post 2

 

[LarryFine]

Its the cut sheet Rating. for 208 volts

Then all of the numbers on the nameplate apply.