Breaker size for FM 60...60 amp, correct?

Freewilley

My wiring centre is incorrect I have been advised...there is a 60 amp breaker between CC and PV array, but none between battery.
I am ordering breakers, should be 60 amp?
Also, is there a breaker or box that can stand alone nicely, my main panel is pretty tight.

BB.

If you want full 60 amp rated output from the FM 60--then:

• 60 amps * 1.25 NEC derating = 75 amps ~ 80 minimum breaker/wiring rating

Was that your question?

-Bill

BB.

I should add that outback may have 63 amp rated circuit breakers too. Different from NEC rating method.

-Bill

Vic

Hi Willey,

First, you will want breakers rated for DC operation on the CC in, out, and on the inverter.

A 60 A DC breaker is probably OK on the input of the CC.

When choosing breakers (of fuses for that matter) just remember that the size of the cable dictates the maximum breaker size that you can safely use. And if a breaker rating is increased, please check that the existing cable will be able to safely handle the added current.

You could use the MidNite MNEPV breakers -- they are Rated for Continuous current (unlike some, although not everyone likes this approach to rating breakers) The standard MNEPVs have ratings from 1 - 63 Amps, and take a single DIN breaker slot in standard Solar style boxes:
http://www.solar-electric.com/instal...br1/mnepv.html

Then there are DIN Rail mount breakers Rated at 80 and 100 A, that require two DIN breaker slots:
http://www.solar-electric.com/instal...omn150vdc.html

These breakers are a bit expensive, at about USD 40.

Here is a box that will accommodate the DIN Rail breakers:
http://www.solar-electric.com/instal...obigbabox.html

This is the MN Big Baby box, which can accommodate up to four single-width DIN breakers (do NOT recommend using the Baby Box, as it is SO small that it is difficult to route cables, etc).

Since you feel that you will need an additional box to mount the added breakers, perhaps you could consider the MNEDC breakers, which mount from the front:
http://www.solar-electric.com/instal...amodccibr.html

These breakers are relatively inexpensive, and have Ratings to 100 A (Continuous), with the standard single-width of 0.75" for this series of MNEDCs.

This box, the MNEDC-Quad, will accept up to four of the 3/4" wide MNEDC breakers, and has a reasonable amount of room:
http://www.solar-electric.com/installation-parts-and-equipment/midnite/elenanddcdi/mnedc-quad.html

If you will need a Disconnect/Breaker for your inverter, the appropriate box to mount it, and the others that you want to add, would probably change.

FWIW, Vic

Freewilley

Vic....thanks so much. You put a lot of effort into your answer and it is really appreciated.

Apples

Your battery positive should be fused/breaker'd for the ampacity of the cable connecting it, and within 6 inches of the battery positive terminal. That's what I hear, anyway. Dunno if the otherwise-very-helpful-and-informative replies touched on where, ideally, the battery's breaker should be placed.