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Ac input disconnects

Posted: Wed Jul 29, 2015 8:28 am
by cbesolar
Hello All,

I have been noticing that the AC input switch keeps disconnecting at night, causing it to use battery power. Any idea why AC input breaker trips? I am not drawing too much load though. Thanks.

KC

Re: Ac input disconnects

Posted: Thu Jul 30, 2015 6:30 am
by larrywa
cbesolar wrote:Hello All,

I have been noticing that the AC input switch keeps disconnecting at night, causing it to use battery power. Any idea why AC input breaker trips? I am not drawing too much load though. Thanks.

KC
What size is the breaker?

How many times has the breaker tripped?
How old is the breaker?
Does the breaker feel warm when it is working?

Re: Ac input disconnects

Posted: Thu Jul 30, 2015 8:52 am
by cbesolar
4-5 times now.
The unit is about 4 years old.
No, not particularly warm.

Re: Ac input disconnects

Posted: Thu Jul 30, 2015 10:30 am
by Vic
Hi cbesolar,

Eventhough the breaker does not seem particularly warm, if is a good idea to check and re-torque wire connections. The terminal connections should be TIGHT.

Copper cold-flows over a period of time, and this relaxes the torque on connections, especially if these connections were not torqued sufficiently, initially.

This re-torqueing should really be done with power OFF to the circuits being worked on ... if one is very careful, and you have the proper sized screwdriver with an insulated shaft, if can be done with the power on (IMO).

Loose connections cause higher resistance connections, and this increased resistance causes a voltage drop, and increased heat inside the breaker.

And, generally, the more times that a Thermal, or Thermal-Magnetic breaker trips, the more sensitive they usually become (and therefore trip at a lower current), at least, in my experience.

FWIW, Vic