LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Well, I was called to look at a job I haven't done before. A contractor called me to price running power to a pair of 10-HP pumps in an industrial park. The motors can be wired for 480v, with a rated current of approximately 12.5a, which obviously reduces conductor sizing, but possibly increases equipment cost.
The basic job includes coordinating with the POCO to bring 480v 3ph to a service panel, possibly involving extend their primary to new transformers, but they may opt to run secondaries to to the relatively small load. I don't yet know the secondary voltage at the last transformer bank, a couple of hundred feet away.
From the service panel location, I have about 75 feet of parking-lot asphalt to the nearest of the four big tanks on piers, where I have the option of running above ground about 50' to the two tank control switches, and from each about 25' to the two motors. I'm thinking two conduits from the panel, rather than one.
My questions have more to with the need for explosion-proof equipment and seal-offs: 1. Is rigid steel the best, easiest, or only option? 2. Does each end of each conduit run require sealing? 3. What about flexible connections to the motor compartments? 4. Do I request 480/277 for possible site-lighting?
Anything you can tell me or point me to would be greatly appreciated!
The basic job includes coordinating with the POCO to bring 480v 3ph to a service panel, possibly involving extend their primary to new transformers, but they may opt to run secondaries to to the relatively small load. I don't yet know the secondary voltage at the last transformer bank, a couple of hundred feet away.
From the service panel location, I have about 75 feet of parking-lot asphalt to the nearest of the four big tanks on piers, where I have the option of running above ground about 50' to the two tank control switches, and from each about 25' to the two motors. I'm thinking two conduits from the panel, rather than one.
My questions have more to with the need for explosion-proof equipment and seal-offs: 1. Is rigid steel the best, easiest, or only option? 2. Does each end of each conduit run require sealing? 3. What about flexible connections to the motor compartments? 4. Do I request 480/277 for possible site-lighting?
Anything you can tell me or point me to would be greatly appreciated!