I have a job where new equipment has been installed. Currently there is a 60A sub panel 120/208 3 phase. It is 425' from the service. the new pool heater is a 120V single phase 20A load, (2 motors), with the other loads (2 other circulating motors and pool lights) there is 28A on 2 legs and 48A on C phase. The pool company hooked it up, they had 109V at the heater which made some of the controls in the heater not work. They called me, I suggested a new 100A panel. Conduit is 4" most of the way, but goes to 1 1/2 after the last pull box. It's about 35' to the panel location. By pulling 2/0 THWN most of the way, the suggested wire by my VD calculator online, splicing #1 THWN at he pull box before the panel, the VD will go up a little, but am I thinking the right direction. Don't think I can get #2/0 into the 1 1/2 PVC. Opinions?
Voltage drop
- Thread starter solis
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Have not done the math when the equipment ground is added but it's doubtful you can or would want to.
Since your actual load is on 48 amps it looks like you would only have a 3% drop with a #1 so unless you anticipate an added load, I would use #1 or 1/0 at most.
Since your actual load is on 48 amps it looks like you would only have a 3% drop with a #1 so unless you anticipate an added load, I would use #1 or 1/0 at most.
I considered that, Thanks
Coppersmith
Senior Member
- Location
- Tampa, FL, USA
- Occupation
- Electrical Contractor
A small boost transformer might solve the problem cheaper assuming you are not overloading the feeders.
- Occupation
- Licensed Electrician
Not a good idea. Voltage drop rises and falls with the load. If you boost the voltage enough for peak load then the voltage will be too high at minimum load.
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