Page 1 of 1

Flexpower controller + breakers wiring

Posted: Sun Aug 16, 2015 11:53 pm
by nztomas
Hello there,

I've bought second hand (unused) Flexpower 1 48v3kw which doesn't have a FM controller installed. I'm going to add my existing FM60 controller but I just want to be sure that I do it right. There are no PV/Controller breakers installed too. So I would like to buy:

1) 40A breaker for PV circuit (I have two string of 3x250W panels, each string (~100V @ 7.6A) has it's own 10A breaker directly on pole, the flexpower is than 15m from panels) - I intend to add another 2 strings later on so 35A-40A breaker on flexpower should be okay? Or should I add 20A breaker now and after adding those 2 string upgrade to 40A ?
2) 60A controller breaker (or should I go with 80A when adding FM60?)

Also I can't find any details how to wire these breakers with controller. Any chance someone could draw or take a picture of the actual wiring of DC enclosure of his Flexpower 1? I'm attaching pictures of mine flexpower with missing wiring + breakers.

Many thanks in advance!

Tomas

Re: Flexpower controller + breakers wiring

Posted: Mon Aug 17, 2015 7:25 am
by larrywa
No larger than the 60A. Typically you always use o/c protection for the wire size, not the equipment.

I have individual branch breakers for each PV string (in my combiner) and a supplied common breaker on input and output for 80A for each FM80 unit in the FlexPower II breaker box. They were supplied but the wiring supplied (#8) was not large enough for the breakers and had to be replaced with #6 copper due to the derating rules of over three conductors in conduit.

Note these breakers are not your everyday breaker for DC. They are special and can be expensive.

Re: Flexpower controller + breakers wiring

Posted: Fri Aug 21, 2015 7:21 pm
by larrywa
nztomas wrote:Hello there,

I've bought second hand (unused) Flexpower 1 48v3kw which doesn't have a FM controller installed. I'm going to add my existing FM60
....
Also I can't find any details how to wire these breakers with controller. Any chance someone could draw or take a picture of the actual wiring of DC enclosure of his Flexpower 1? I'm attaching pictures of mine flexpower with missing wiring + breakers.

Many thanks in advance!

Tomas
Have a look at this.

http://www.outbackpower.com/downloads/d ... SGREVA.pdf

OB has a tonne of info out there but some intensive digging is required to find it sometimes.

Re: Flexpower controller + breakers wiring

Posted: Tue Oct 27, 2015 1:17 am
by nztomas
I've wired the flexpower + two breakers and FM60 and I'm uploading the result just in case someone would end up in the similar situation as me. Not really sure if it is hundred percent correct, I'm not an electrician - but it works fine for last couple of months...