Pole light circuit breaker size

Status
Not open for further replies.
C

Craigse

Member
Can I change the breaker size from 20 amps to 25-30 on a pole light circuit if the wires are #10? I can't find it in the code book.
 
I think your looking for 210.21(A) and 210.23(B)
and 210.24

If the pole light does not have heavy-duty lampholder you will not be able to.
 
Last edited:
Craigse,
You should be able to go up to 30 amps, but let me explain, without knowing FLA.
size #10 wire needs to have a derating factor based upon ambient temp. I chose 40 degrees C in your example 104 degrees F, as max worst case. The table is 310.16. With 240.6 in mind and 240.4 you might be only protecting the wire and not the other components.
Just my $.02
 
I have some questions:
Is this a new install?
If an existing install, is the 20A tripping?
Has VD been considered?
Why do you want to up the CB size?

I think these questions need to be answered BEFORE anyone can give an answer
 
It is an existing job but the electricians doing the job overloaded the circuits. They put 4 pole light heads on each circuit. Each head has 2 of 180 watt Low pressure sodium lamps. There are 2 circuits with a shared nuetral running a total of 8 heads. Both circuits are running at around 19.5 amps. If the pole are shut off and them started again (restrike) then it runs at around 20.7 amps.
 
Craigse said:
It is an existing job but the electricians doing the job overloaded the circuits.
Click to expand...
Not so fast grasshopper....


Craigse said:
They put 4 pole light heads on each circuit. Each head has 2 of 180 watt Low pressure sodium lamps.
Click to expand...
What is each fixture rated at?


Craigse said:
There are 2 circuits with a shared nuetral running a total of 8 heads. Both circuits are running at around 19.5 amps. If the pole are shut off and them started again (restrike) then it runs at around 20.7 amps.
Click to expand...

How long is the run?

BTW,are these 480v circuits?
 
so something is really wrong here... if i understand this correctly, there are 8 lights per circuit leg... 8X180W=1440Watts/leg total 1440watts/120volt = 12 amps

so, are these sockets overlamped?, is their leakage current to a ground fault? , is the lenght of the run so long there is 50% loss or am I missing something...

b.t.w. a higher voltage would only drop the amperage, right?
 
abbattista said:
so something is really wrong here... if i understand this correctly, there are 8 lights per circuit leg... 8X180W=1440Watts/leg total 1440watts/120volt = 12 amps
Click to expand...
Assuming the 180w is nameplate...

abbattista said:
b.t.w. a higher voltage would only drop the amperage, right?
Click to expand...
Yup.
 
Are you determining the load based on lamp watts or ballast VA?
Also you may want to try a HID breaker, they are not as likely to trip on inrush.
LPS lights? Don't see those very often.
 
You must use ballast amps.What is voltage of the lights.The number 10 was likely to deal with voltage drop.Unless this was your install i would not think of over fusing to cover up a bad install.
 
Status
Not open for further replies.
Top