njose424
Member
- Location
- Carmel, IN
- Occupation
- Safety Professional
Please help!?!?
My furnace stopped working today and I was able to determine it was a blown fuse. I've currently got the fuse block bypassed to keep the furnace going temporarily.
The blown fuse I removed is a Eagle OK 125V 20AMP Time Delay "D" fuse. I understand this is a Type T fuse because it has an Edison style screw base. Beyond that, my available options for Type T fuses at my local hardware store are a TL (medium duty) or T (heavy duty) rated fuse.
What would be the appropriate replacement fuse? TL or T rated?
On a side note, the electrician at work AND the facilities HVAC engineer both separately told me a local fuse is not necessary because it's on a dedicated circuit. I looked and my breakers are Square D QO type. The breaker is a 20 amp breaker.
Furnace is a Lennox m/n ML180UH090P48B-55
The "Electrical Rating" sticker says the max amps is 12 and the full load amps is 8.2.
Here's what I extracted from the Installation Manual on this topic:
"The power supply wiring must meet Class I restrictions. Protected by either a fuse or circuit breaker, select circuit protection and wire size according to unit nameplate.
NOTE − Unit nameplate states maximum current draw. Maximum over−current protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate wiring.
Install a separate (properly sized) disconnect switch near the furnace so that power can be turned off for servicing."
Not sure if the blown fuse was appropriately rated at 20 amps or if a 15 amp fuse is appropriate. Also, wondering if I need the fuse or can just get away with the 20 amp dedicated circuit breaker but also wondering if that's appropriate for the motor rating.
My furnace stopped working today and I was able to determine it was a blown fuse. I've currently got the fuse block bypassed to keep the furnace going temporarily.
The blown fuse I removed is a Eagle OK 125V 20AMP Time Delay "D" fuse. I understand this is a Type T fuse because it has an Edison style screw base. Beyond that, my available options for Type T fuses at my local hardware store are a TL (medium duty) or T (heavy duty) rated fuse.
What would be the appropriate replacement fuse? TL or T rated?
On a side note, the electrician at work AND the facilities HVAC engineer both separately told me a local fuse is not necessary because it's on a dedicated circuit. I looked and my breakers are Square D QO type. The breaker is a 20 amp breaker.
Furnace is a Lennox m/n ML180UH090P48B-55
The "Electrical Rating" sticker says the max amps is 12 and the full load amps is 8.2.
Here's what I extracted from the Installation Manual on this topic:
"The power supply wiring must meet Class I restrictions. Protected by either a fuse or circuit breaker, select circuit protection and wire size according to unit nameplate.
NOTE − Unit nameplate states maximum current draw. Maximum over−current protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate wiring.
Install a separate (properly sized) disconnect switch near the furnace so that power can be turned off for servicing."
Not sure if the blown fuse was appropriately rated at 20 amps or if a 15 amp fuse is appropriate. Also, wondering if I need the fuse or can just get away with the 20 amp dedicated circuit breaker but also wondering if that's appropriate for the motor rating.
