I am working with a relatively new install that was done by an EC approx 2 years ago. The EC ran 4 4/0 AL conductors in a 2.5" pvc underground and into a trough to feed a 200A disconnect for a piece of machinery. The disco at the meter is 200A, shouldn't the OCPD for that install be no larger than 175A?
4/0 AL 75C
- Thread starter nizak
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jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
If the install is 2005 NEC, yes 175 amps
2008 is 150 amps
Machinery is a motor? 430.62(A) does not allow next size up for motor feeders. Yet, T430.52 allows for inrush.
Need more information on the install.
2008 is 150 amps
Machinery is a motor? 430.62(A) does not allow next size up for motor feeders. Yet, T430.52 allows for inrush.
Need more information on the install.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Brain fart, disregard.:slaphead::ashamed1:
chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
The install sounds compliant to me. The 4/0 is good for 180A then throw in 240.4(B).
kwired
Electron manager
- Location
- NE Nebraska
4/0 aluminum @ 75 deg is good for 180 amps. You are allowed to protect it with next standard size higher which is 200 amps. As long as calculated load on these conductors is not over 180 this is acceptable. If load is between 180 and 200 then you need larger conductors but can still use a 200 amp overcurrent device.
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