jhall

I am wiring a single phase 15 h.p. 240 v. pump and not sure just how to size branch circuit protection,fuse size, and conductor size.
I have looked at franklin pump chart and pump f.l.a is 60 amps. Frankling recommends 175 amp fuses. This seems strange to me. I am considering installing a 200 amp mobile home panel on outside of pump house, feeding a 200 amp rated fused safety switch back to back of service panel inside pump house and install 175 amp fuses in disconect and feed from fused safety switch over a few feet to 15 hp pump controll panel with # 4 copper thhn since the pump f.l.a. is 60 amps x 1.25% is 75 amps. Pump is wired with # 6 THW 20' down to pump. I am out of my comfort Zone with this and need some advice on how to proceed. Do I feed 200 amp fused safety switch with 3/0 copper or #4 copper, or do I feed 3/0 copper from meter to safety switch and then out of safety switch to pump controller with #4 copper. Not sure. HELP!!!

Joe Momma

Are you an electrician? Perhaps you should call one.....

Use the nameplate fla to size the overloads and table 430.150 to size everything else.....

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jhall

pump is single phase 230 15 hp 430-150 table goes to 10 hp no overloads in system only fused protection.

JohnJ0906

Will the 200 amp panel be used for any other loads?

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John from Baltimore
"One day at a Time"
All responses based on the '08 NEC
It's not my fault, it's not my problem, I'm not your solution.

jhall

light inside pump house and light outside man door to pump house and service receptacle.

JohnJ0906

1) feeder to panel : NEC 215 (remember voltage drop)
200 amps seems like overkill
2) the rest of this comes under NEC 430
I suppose since a 240v 1ph motor isn't listed in the 430 tables, you would use the nameplate FLA, but I am not positive.

When looking at 430, I start at figure 430.1. It makes it easier to calculate everything in order, so to speak.

__________________
John from Baltimore
"One day at a Time"
All responses based on the '08 NEC
It's not my fault, it's not my problem, I'm not your solution.

Joe Momma

table 430.148 refers to single phase motors, but it only goes up to 10 horse.
So you'll have to work from the nameplate values.

And I've never known it to be overkill to install a panel larger than the job at hand.

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Joe Momma was here

John

Use #4 wire
100 amp time delay fuse in a good quility 100 amp fused disconnect
100 amp circuit breaker in 200 amp panel
Make sure everything is at least NEMA 4 rated

jhall

thanks for the info. figured 60 amps fla x125% = 75 amps so will feed #4 thhn off 80 amp c.b. feeding to 100 amp fused safety switch with 90 amp dual element time delay fuses. thanks for help.

JohnJ0906

You may wish to check table 430.52

Inverse time breaker- FLA x 250%
Time delay fuse - FLA x 175%

__________________
John from Baltimore
"One day at a Time"
All responses based on the '08 NEC
It's not my fault, it's not my problem, I'm not your solution.

jhall

taking info straight off of Franklin 15hp single phase 230 volt chart for dual element time delay fuses

John

You have to remember that table 430.52 is the Maximum rating or setting. And going by what the manufacturer of the equipment recommends is the better choice.