notwellman
Member
what is the rated capacity for a 30' run of copper stranded 8 gauge?
wire capacity
- Thread starter notwellman
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notwellman
Member
Re: wire capacity
the #8 is in BX for an air conditoning disconnect.
upgrading to a 5 ton compressor with a 50 amp draw
the #8 is in BX for an air conditoning disconnect.
upgrading to a 5 ton compressor with a 50 amp draw
hmspe
Senior Member
- Location
- Temple, TX
- Occupation
- PE
Re: wire capacity
#8 copper is rated 40A per table 310-16. 1999 NEC 110-14(c)(1)(a) says that the 60 degree C column ampacity must be used unless the terminations at both ends are labeled for a higher temperature. You may also need to consider derating for ambient temperature in selecting the conductor size.
#8 copper is rated 40A per table 310-16. 1999 NEC 110-14(c)(1)(a) says that the 60 degree C column ampacity must be used unless the terminations at both ends are labeled for a higher temperature. You may also need to consider derating for ambient temperature in selecting the conductor size.
notwellman
Member
Re: wire capacity
thanks for the reply, so the distance of the run isn't significant in this case?
thanks for the reply, so the distance of the run isn't significant in this case?
- Location
- Lockport, IL
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- Semi-Retired Electrical Engineer
Re: wire capacity
The distance of the run is never a factor in determining a cable's ampacity. It may, however, become a factor in providing sufficient voltage at the end of the run. Sometimes, you will need to use a larger wire for the same current, in order to limit voltage drop. But 30 feet is generally not a long enough run to worry about voltage drop.
The distance of the run is never a factor in determining a cable's ampacity. It may, however, become a factor in providing sufficient voltage at the end of the run. Sometimes, you will need to use a larger wire for the same current, in order to limit voltage drop. But 30 feet is generally not a long enough run to worry about voltage drop.
- Location
- Illinois
- Occupation
- retired electrician
Re: wire capacity
What is the minimum circuit ampacity shown on the equipment nameplate? The conductor ampacity must equal or excced the minimum shown on the namplate. If the minimum circuit ampacity is not shown, you must have conductors sized for at least 125% of the full load running current.
Don
What is the minimum circuit ampacity shown on the equipment nameplate? The conductor ampacity must equal or excced the minimum shown on the namplate. If the minimum circuit ampacity is not shown, you must have conductors sized for at least 125% of the full load running current.
Don
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