Mcb rcd rcbo

[Markc]

Hi Mark C,

According to the 17th Edition 712.411.3.2.1.2 a type B RCD is required, the same applies for RCBO's.

Bugger better get the book out from under the desk again!

 

[Markc]

Hi Mark C,

According to the 17th Edition 712.411.3.2.1.2 a type B RCD is required, the same applies for RCBO's.

Hang on Type B or Class B?

 

[solgen]

MCB's Type A, B, C, etc
RCD's Class A, AC, B (also referrred to as type)
RCBO's are both so usually Type {x}, class {x}

 

[miah205]

sorry to be a pain in the back. Just wanted to ask can u reply with anything regarding electrics as im not sure if my messages are being posted as this is the first time ive joined a forum. not very good with websites!!!!

 

[solgen]

miah205,

This part of the electrical forum is specific to solar PV. Depending upon the nature of your question this might not be the most appropriate of the forum for your question. Please have a look at the categories available to post to. There is a general category.

 

[Markc]

I think a big thank you to Solgen is in order here!

Not one to sit back I have done some research. There are specific Class B RCD's out there and RS do one by ABB. See links.

The BRB states: 712.411.3.2.1.2:

Where an electrical installation includes a PV power supply system without at least simple separation between the A.C side and the D.C side, an RCD installed to provide fault protection by automatic disconnection of supply shall be Type B according to IEC60755 Amend 2.

Where the PV converter is, by construction, not able to fed D.C fault current into the electrical installation, an RCD of Type B according to IEC60755 Amed 2 is not required.

So inverters without separating transformers WILL require a Type B RCD.

I've put a couple of links below all from ABB and a RS link. Cost of PV RCD as they call it is £80 and is rated at 300mA.

Again good work Solgen for bringing this up.

ABB | Electrical Installation | Consumer Units | RCCBs | Protection Devices |2CSF202121R3400
http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/40abe76927e9e01dc12576ba003c22bf/$file/solar%20cat%20lr%20v.06.pdf

 

[Energetic]

So another case for an isolating transformer inverter. No hassles with earthing the array frame and no need for exotic rcd's. I'm sold...

 

[solgen]

I've not used TL inverters for most of the above reasons, however, if used the dti guide talks about earth-rod spiking when system is a PME. Any tips with this or has someone come up with a clever way around this?

 

[Martin Dawes]

As the regs are, I can't see any alternative to earth-rod spiking when using PME unless an Isolating Transformer inverter is used.

Maybe the regs could be relaxed for roof mounted PV systems?