Upgrading from FM 60

[bbbuddy]

We currently have an FM60 mounted on top of an MNDC box.  800 watt array.

I am about to order a Classic 150.  We are a 24v system, and will have a 2200 watt array, IMP 78, VOC 99.6.

Obviously the in/out pv breakers need to be changed for the Classic 150 and bigger array.  But with the potential output of the 150, shouldn't the output breaker be at least 100 amp?  Especially with the potential output as high as 94a?

So, the only 100 amp breaker I can find is not a din rail mount, but a panel mount... do I need to get a quad box just for it, or is there a way to modify the MNDC for it?

I can just mount the new incoming pv breaker on the MNDC since it can be a smaller Din rail type...

also, am running 2 wire runs from the array (two combiner boxes) and then need to combine (parallel, same voltage) into one + wire for the controller, is it better to combine them before a single larger breaker, or keep the present breaker, add another one for the new panels, then combine the 2 + wires before the controller? or does it not matter?

thanks in advance

[Halfcrazy]

The MNDC can do either Panel mount or Din rail so if you have no use for Din rail breakers you could swap the plate and use 2 panel mount breakers. I would use a 100 amp for the battery side.

As far as where to combine the 2 + wires from the arrays I would say that could go several ways. If both arrays are similar and the wire size is large enough for the one single breaker you could go that way. I would be more tempted to use separate breakers myself it would also allow for easier system troubleshooting.

Ryan

[bbbuddy]

The MNDC can do either Panel mount or Din rail so if you have no use for Din rail breakers you could swap the plate and use 2 panel mount breakers. I would use a 100 amp for the battery side.

  Plates?  Do you mean the din rail is replaceable?  But I would still need the din rail for the incoming breaker(s)

As far as where to combine the 2 + wires from the arrays I would say that could go several ways. If both arrays are similar and the wire size is large enough for the one single breaker you could go that way. I would be more tempted to use separate breakers myself it would also allow for easier system troubleshooting.

Ryan

This is a good idea I hadn't thought of...and yes one array is 75v, the new one is 78.6v - under 5% difference

[Halfcrazy]

The MNDC would have come with 2 different side plates one for Din rail and one for Panel Mount. You can get Panel mount breakers from 5 to 100 amps so you "Could" change the plate and use all panel mount to save buying a Quad Box.

Ryan

[bbbuddy]

The MNDC would have come with 2 different side plates one for Din rail and one for Panel Mount. You can get Panel mount breakers from 5 to 100 amps so you "Could" change the plate and use all panel mount to save buying a Quad Box.

Ryan

hmmm, ours didn't come with two different side plates so i didn't know this...and yes I just saw that I can get the panel mount pv+ breakers in 20 amp, didn't know that.  so now I have to find out if Naws can sell me a panel mount plate.  thanks!

[Halfcrazy]

If not let me know.

[bbbuddy]

Thank you