can type 8/2 w/g nm-b wire be used with 50 amp overcurrent protection when ran to an electric furnace. The "b" designates 90'C rating. i know this is a close call. I'm trying to make it safe. the hvac guy that installed it two months ago has it on a 60 amp breaker. This is in a church that hired me to add some outlets. the hvac guy has disappeared.
overcurrent protection
- Thread starter sparky59
- Start date
- Status
- Location
- Logan, Utah
Re: overcurrent protection
424.3 (B) Requires the sizing of the branch circuit conductors, and overcurrent device, to be 125% of the total load of the fixed electric space heating equipment.
334.80 says that ampacity of NM cable shall be in accordance with the 60 degree column. You can use 90 degree column for derating only.
With that being said I would say no.
Chris
424.3 (B) Requires the sizing of the branch circuit conductors, and overcurrent device, to be 125% of the total load of the fixed electric space heating equipment.
334.80 says that ampacity of NM cable shall be in accordance with the 60 degree column. You can use 90 degree column for derating only.
With that being said I would say no.
Chris
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: overcurrent protection
First lets start with the min breaker is on the electric heater.That will be on the name plate on unit.How many KW is this unit ?
[ December 08, 2005, 06:33 PM: Message edited by: jimwalker ]
First lets start with the min breaker is on the electric heater.That will be on the name plate on unit.How many KW is this unit ?
[ December 08, 2005, 06:33 PM: Message edited by: jimwalker ]
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