Main Breaker goes off....

spiral

Hi
I have 4 vacation rental apartments with there own breakers running off a main breaker. The main breaker is big enough.
Twice now the main breaker goes off and no others. This makes it difficult to isolate the problem of course.

1. Under what situation would the main breaker go off and not the smaller ones?
2. What should I do to correct this problem?

I need to change electricians but anything else?

Thanks all

Scuba_Dave

The main breaker usually kicks off when too much load has been placed on it
Also possible its getting older & failing

How big is big enough?
What does your electric load calc for the 4 places come out to ?

General

This very well can be a simple short circuit in one of the units. The main breaker might just be tripping before the branch circuit breakers.

Have you spoken to each tenants about exactly what they were doing when the breaker tripped?

spiral

The breaker was upped 2 years ago. I will get the electric company involved.
It might be faulty.

Main breaker is 60A 100Volts. No idea as for the electric load calculation.

Thanks for the reply.

General

100 volts?

60A is pretty small for a 4 apartment dwelling. A couple microwaves, a toaster oven or two, and a hair dryer could easily pop that breaker every morning.

Scuba Dave picked up on the same thing as I did, as soon as you said "The main breaker is big enough." a big red flag went up. Without a load calculation or a lot of experience in the matter, you can't determine whether it is big enough or not.

In most areas the power company will tell you to talk to an electrician since this matter is on your side of the meter. I would look at either an overload (too much current is being drawn) or a short circuit. Talking to your tenants first is your best bet.

spiral

It tripped about 8AM. Pretty much maximum morning peak usage. I use the fourth unit as my office workshop and was also making breakfast. Lucky I was here as I noticed right way.

Thanks all

spiral

1)Japan
2)Yeah I think that has what happened, I never really realized how many amps we use but it looks like any one of these is from 5 to 15 amps and I can see running out of power easily.
3) Hey, I relied on a licensed electrician. What can I say!
4)The power company owns the main breaker.

Thanks all