Proper CBreaker size for 8KW heat strip?
#1
07-24-06, 07:56 PM
Proper CBreaker size for 8KW heat strip?
Had a new Trane heat pump air handler installed today with 8 KW heat strips. It is wired (from the disconnect) with AWG #8 wire I think. The booklet says max overlaod protection @240v is 45 amps or @208 is 40 amps.
The old Goodman had 60 amp breakers but perhaps it had a 10 KW strip. The wire from the breaker to the disconnect is AWG #6.
Looks to me like I should install a smaller breaker to fit the 8 KW strip (and the #8 wire from the disconnect. Since there is no Siemens 45 amp breaker - looks like a 50 amp would be best.
Am I on the right track? Thanks!
The old Goodman had 60 amp breakers but perhaps it had a 10 KW strip. The wire from the breaker to the disconnect is AWG #6.
Looks to me like I should install a smaller breaker to fit the 8 KW strip (and the #8 wire from the disconnect. Since there is no Siemens 45 amp breaker - looks like a 50 amp would be best.
Am I on the right track? Thanks!
#2
07-25-06, 08:08 AM
My Trane units say right on the blower unit door
1 ph 208V= 7.20 Kw calls for a 50 amp
240V= 9.60 Kw calls for a 60 amp breaker keep the #6 wire
Im sure you look at the 3 Ph thats what it calls for the 45 and 40 breaker.
ED
1 ph 208V= 7.20 Kw calls for a 50 amp
240V= 9.60 Kw calls for a 60 amp breaker keep the #6 wire
Im sure you look at the 3 Ph thats what it calls for the 45 and 40 breaker.
ED
#3
07-25-06, 08:04 PM
I looked again at the data in the literature that came with the air handler. You have a bigger strip than I have.
At 240V:
single phase 7.68 KW (my heater) - Max overload protection = 45 amp. Only comes single phase.
Other strips shown in the literature:
single phase 9.6 KW (your heater)- 60 amp.
3 phase 9.6 KW (your heater)- 45 amp.
At 208V:
single phase 5.76 KW (my heater) - Max overload protection = 40 amp. Only comes single phase.
Other strips shown in the literature:
single phase 7.2 KW (your heater)- 50 amp.
3 phase 7.2 KW (your heater)- 40 amp.
At 240V:
single phase 7.68 KW (my heater) - Max overload protection = 45 amp. Only comes single phase.
Other strips shown in the literature:
single phase 9.6 KW (your heater)- 60 amp.
3 phase 9.6 KW (your heater)- 45 amp.
At 208V:
single phase 5.76 KW (my heater) - Max overload protection = 40 amp. Only comes single phase.
Other strips shown in the literature:
single phase 7.2 KW (your heater)- 50 amp.
3 phase 7.2 KW (your heater)- 40 amp.
#4
07-25-06, 08:42 PM
We would let it as is. but if you want put it on a 50 amp breaker but let the #8 wire as is. Dont forget you still have a blower motor with about 4.30 amp draw and a transformer also in the unit that needs power.
ED
ED
