2 soladin 600

[jdr01red]

evening all, was hoping for a bit of advice from someone in the know?

I am planning a small install, I have 2 very small roofs to use. 1 roof faces s.s.e the other faces sw. space is limited on both and to be honest so is my budjet!

I was looking to install 6x 200Wp modules, split into 2 strings, with 1 string on each roof. The only inverter(s) suitable are the mastervolt 600 Soladin.

So will it be ok to use 2 x soladin 600, 1 for each string, each with their own DC and AC isolators, and then fed into a joint box, with 1 feed back to 1x generation meter,1x main isolator and 1x MCB??

I have C&G 2399 and have read lots of books and info including the inverters destruction manual but cant find any guidance on this. I know if it was a larger system the best bet would be to use a twin Mpp tracker inverter but my system wont be big ebough.

I am planning to use the install for my MCS assessment, so need it to be right, but am not sure about 2 inverters being fed from 1 MCB, have read conflicting views on this?

Soz for rambling and long message, any help would be much appreciated

 

[Markc]

I would recommend one inverter one MCB.

 

[northernsun]

i'm curious to know why 2 MCB's? I used to do loads of systems like this for newbuilds that just wanted the system to meet energy efficieincy code and would often have a couple fo inverters both on the same circuit.

 

[Worcester]

SMA specifically states that each inverter must have it's own MCB

We made this mistake on an early install, two inverters in the loft to an AC junction box then single cabel to one MCB in the CU. We went back and retro fitted a small dual MCB CU in the loft, then still used the single cable to the main CU. So two AC isolators in the loft, 2 x MCB's in CU, then one isolator, one gen meter, and one MCB in the main CU.

 

[northernsun]

very interesting. I've not done any for my own customers but have been involved with thousands like this when I was employed. Always on the same cable and MCB, more often than not soladin but plenty of double sb1200's too. As always I think I will err on the side of caution when this crops up again. Cheers worcester.
As far as the opening poster then i would definately do it with 2 MCB's if it's for you inspection even if there was a doubt - always do more than the minimum is not a bad rule.

 

[northernsun]

I'd be interested to know whether you had any problems with the install worcester, or whether you found out the SMA recommendation and changed it anyway?

 

[jdr01red]

Thanks Worcester and Nothernsun, I think I will either just have to goo for 1 string on the 1 roof or as worcester says install a small c.u in the loft and single cable back to main c.u. It seems crazy to install two MCBs at main c.u, then both feeding into same generation meter....defeats the object really.

My only concern is will the MCS inspecter be happy with c.u in loft method?? cant see why not, but like you say nothernsun always best to err on the side of caution.

I would love to be able to fit bigger system with a single sb1200 or like inverter, but just cant fit a system that size on single roof without going over 300mm from edge of roof....need bigger roof!!!

 

[Worcester]

Nope, no problems it was working just fine (2 x SB1200's), just when we learnt that each should have their own MCB we went back and changed it. - The reason for 2 x SB1200's was that we couldn't find a twin MPP inverter of that size back then.