Generator OC protection

Status
Not open for further replies.
A neighbor bought an 8 kw propane gennie that came with a whip/weather resistant conn. box. Largest wire in whip is 10ga. I'm going to use a lockout device but am unsure of bkr size, but thinking 30a. 8kw/120v though is over 60a. Thoughts?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
A neighbor bought an 8 kw propane gennie that came with a whip/weather resistant conn. box. Largest wire in whip is 10ga. I'm going to use a lockout device but am unsure of bkr size, but thinking 30a. 8kw/120v though is over 60a. Thoughts?
Maybe because the 8kw rating is at 240V?
Many generators cannot deliver their rated output through only half of the output winding.
For example, I have a generator that has a 20A 240V output, but only 30A at 120V on one side of the line.
 
Last edited:

templdl

Senior Member
Location
Wisconsin
A neighbor bought an 8 kw propane gennie that came with a whip/weather resistant conn. box. Largest wire in whip is 10ga. I'm going to use a lockout device but am unsure of bkr size, but thinking 30a. 8kw/120v though is over 60a. Thoughts?
Have you given it some thought that the generator must be able capable of putting out enough overcurrent tyo trip a breasker thermally as well as enough short circuit current to trip a breaker magnetically?
This is very unlikely to happen with a common UL489 breaker as the common generator is not likely sized large enough to do either. Remember that it is not like being supply by a utility.
You may be disappointed should you compare the generation capabilities of the generator to the trip curve of the breaker you propose to use.
 
Status
Not open for further replies.
Top