monkeyhead
Member
So we have this de-facto standard at work for internal installs:
480VAC 3 phase motors (most < 3 hp) - 10 or 12 AWG Black (some of our vendor installs use Brn/Org/Yel of the same AWG rating)
120VAC controls - 14 AWG red
120VAC nuetrals - 14 AWG white
24VDC controls - 16 AWG blue
Grounding - Equivelant AWG of above mentioned with Green wire
In almost all cases this wiring is way over rated for what it is doing. The main reason that I can see that this is the de-facto internal standard is because this is analagous to the standards that multiple vendors and electrical contractors install our equipment with.
So copper can get kinda pricey along with larger conduit and accessories to support the larger gauges... why does this seem to be so common? Voltage drop shouldn't be an issue because in almost every case (except on conveyor runs) the distance is less than 50 ft.
Anyone else in the field see this and ever wonder why? I can't seem to fathom why a 1/2 HP motor 20 feet from the cabinet needs 10 AWG wiring.
The other thing I don't get is that the electricians are so finicky about matching up the ampacity requirements for the power feed to the gauge wire they are running, but then once they're in the cabinet, it's all over-rated.
480VAC 3 phase motors (most < 3 hp) - 10 or 12 AWG Black (some of our vendor installs use Brn/Org/Yel of the same AWG rating)
120VAC controls - 14 AWG red
120VAC nuetrals - 14 AWG white
24VDC controls - 16 AWG blue
Grounding - Equivelant AWG of above mentioned with Green wire
In almost all cases this wiring is way over rated for what it is doing. The main reason that I can see that this is the de-facto internal standard is because this is analagous to the standards that multiple vendors and electrical contractors install our equipment with.
So copper can get kinda pricey along with larger conduit and accessories to support the larger gauges... why does this seem to be so common? Voltage drop shouldn't be an issue because in almost every case (except on conveyor runs) the distance is less than 50 ft.
Anyone else in the field see this and ever wonder why? I can't seem to fathom why a 1/2 HP motor 20 feet from the cabinet needs 10 AWG wiring.
The other thing I don't get is that the electricians are so finicky about matching up the ampacity requirements for the power feed to the gauge wire they are running, but then once they're in the cabinet, it's all over-rated.