good morning i have a question concerning wire size for a 120 volt circuit coming coming from a 240 volt sub panel in a manufacturing plant and running 300 feet to power a gate opener and a gate light . the gate opener has a 115v 11.3 amp motor, the pole light is a high pressure sodiom with a 190 input watts . from my calculation i am coming up with 6 awg to keep the drop within the 3% recomended by the NEC . Would like to know if i am right on my calculation. also, the wire would be fun under ground in conduit .
voltage drop to gate opener and gate light
- Thread starter Jay2685
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I get #6 AWG also using a load of 13 amps. Since the gate has a motor you want to ensure that the voltage drop isn't very large when the motor starts up. For 240 volts I get #8 AWG.
MAC702
Senior Member
- Location
- Clark County, NV
I'd be verifying that gate opener can't take 240V. It'd be easy to get a 240V light if it could.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
The suggestion was, if possible, to change the circuit to 240 to reduce wire cost. Since you are talking about pulling new wire anyway, could you add a new breaker and make it 240?
MAC702
Senior Member
- Location
- Clark County, NV
LOOK AT THE MOTOR PLATE AND VERIFY IT CAN'T BE SWAPPED TO 240V.
But, yes, the rest of the controls may matter as well, which is why I simply said to verify that the equipment as a whole couldn't be changed. Some can. A lot of them can. It's worth the look.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Possible to run 10-3 and make it a MWBC with two 120v circuits?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
That could potentially reduce the voltage drop when the motor and the light are both on at the same time.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
As you do your comparisons, keep in mind that because the current drops and the reference voltage increases, doubling the voltage allows you to use one quarter the size conductors for the same percentage voltage drop.
ptonsparky
Tom
- Occupation
- EC - retired
I would be for putting a 120/240 4 wire feeder out there and not scrimping on the details. The ditch for a 1/2” conduit will cost the same as one for a 2”, or two 2”.
At the very least, make the suggestion.
At the very least, make the suggestion.
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