1600A service
- Thread starter richf
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
Re: 1600A service
If the service OCPD is a single 1600 amp device, then you will need 5 sets of 500kcmil. Four sets of 500 kcmil is only 1520 amps. If you only have the 4 raceways you could install eight 4/0s in each of the four raceways and have 1664 amps of wire or you could use eight 350 kcmil in each of three raceways and have 1680 amps. These assume that the grounded conductor is not required to be counted as a current carrying conductor.
Don
If the service OCPD is a single 1600 amp device, then you will need 5 sets of 500kcmil. Four sets of 500 kcmil is only 1520 amps. If you only have the 4 raceways you could install eight 4/0s in each of the four raceways and have 1664 amps of wire or you could use eight 350 kcmil in each of three raceways and have 1680 amps. These assume that the grounded conductor is not required to be counted as a current carrying conductor.
Don
charlie
Senior Member
- Location
- Indianapolis
Re: 1600A service
I would think it would be simpler to use 4 sets of 600 kcmil.
I would think it would be simpler to use 4 sets of 600 kcmil.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: 1600A service
You might want to see 240.4(C) and compare it to 240.4(B).
You might want to see 240.4(C) and compare it to 240.4(B).
Re: 1600A service
Steve
I agree, it would be simpler to install 600's. But the 8 sets of 4/0 is actually less copper (each pair of 4/0 is about 423KCM instead of 600KCM) for about the same ampacity. Voltage drop would probably be less also.
Steve
- Location
- Illinois
- Occupation
- retired electrician
Re: 1600A service
If I have to do the work, I'd choose 4/0s over 600 any day.
Don
If I have to do the work, I'd choose 4/0s over 600 any day.
Don
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: 1600A service
See 110.14(C) Termination provisions. The 90 degree rating will not be allowed to be used.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: 1600A service
Medium voltage terminations have been rated 90C for some time; in fact, I can't remember when they weren't. That rating is buried in the IEEE standards though, not the UL standards. UL evaluates MV switchgear and Transformers to the IEEE standards as well as their own.
The Category Code almost all electrical equipment is evaluated to is AALZ, "Equipment for Ordinary Locations." That is the fundamental standard that Section 110.14(C) was based on. AALZ requires not only the terminal but the equipment it is installed in to be evaluated before a 90C terminal rating may be applied.
I did a quick scan in the UL (1558) and IEEE (C37.20.1) standards for low voltage switchgear and couldn't find 90C recognized for terminal ratings.
The search was by no means exhaustive, but I'm curious which manufacture is offering 90C rated terminals in their low voltage switchgear.
Why are so many electrical engineers in a rush to see how marginal their design can be in industrial applications? I believe the NEC is excessive in many places but conductor ampacities is generally not one of them. Frankly, I believe the reason we've gotten excessive in many other areas, is because conductor ampacities are often too marginal.
Edit added: Present company excepted, of course.
[ July 21, 2004, 03:05 PM: Message edited by: rbalex ]
Medium voltage terminations have been rated 90C for some time; in fact, I can't remember when they weren't. That rating is buried in the IEEE standards though, not the UL standards. UL evaluates MV switchgear and Transformers to the IEEE standards as well as their own.
The Category Code almost all electrical equipment is evaluated to is AALZ, "Equipment for Ordinary Locations." That is the fundamental standard that Section 110.14(C) was based on. AALZ requires not only the terminal but the equipment it is installed in to be evaluated before a 90C terminal rating may be applied.
I did a quick scan in the UL (1558) and IEEE (C37.20.1) standards for low voltage switchgear and couldn't find 90C recognized for terminal ratings.
The search was by no means exhaustive, but I'm curious which manufacture is offering 90C rated terminals in their low voltage switchgear.
Why are so many electrical engineers in a rush to see how marginal their design can be in industrial applications?
I believe the NEC is excessive in many places but conductor ampacities is generally not one of them. Frankly, I believe the reason we've gotten excessive in many other areas, is because conductor ampacities are often too marginal.Edit added: Present company excepted, of course.
[ July 21, 2004, 03:05 PM: Message edited by: rbalex ]
- Status