RCD Type B ???? 1

[plcman]

Hi

Can anybody tell me who manufactures a 'type B RCD', this is a type which is suitable for use on smooth DC. The type reference is not related to the tripping characteristic of a circuit breaker or combined circuit breaker / RCD.

Any help greatly appreciated.

Regards

Alan Edwards

 

[jbartos]

Suggestion: Visit

http://www.nuaire.co.uk/IandM/micromaster1.pdf

for Section 1.3.2 Operation with Residual Current Device (RCD)

 

[ScottyUK]

Most RCDs use some form of core-balance CT through which all the circuit conductors pass, but not the protective earth. There are Type A and Type AC RCDs, of which Type AC has sensitivity to pulsating DC but not pure DC. Obviously any sort of current transformer won't be much use on pure DC, so the Type B - assuming there is such an animal - must use a completely different technique.






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Never look down any at anybody, unless you are helping them up.

 

[plcman]

Hi

I know that a type B does exist, any inverter / drive system manufacturer includes reference to them in their docs, unfortunately they don't seem to be able to point to a manufacturer.

My problem is futher complicated by the fact that I need a 100A RCD, any manufacturer who makes something that resembles a type B only goes to 63A

Regards

Alan Edwards

 

[jbartos]

Suggestion: Above certain ratings the personal safety is taken over by fire protection and safety. Therefore, the higher rated RCD are hard to come by. E.g., there are GFCI receptacles mostly rated 15A and 20A in USA.

 

[busbar]

Posted for C-H...

"You could check out the Bender RCD's, in particular the RCMA470LY / RCMA475LY.

http://www.bender.org/prod.html

I installed one of these (the RCMA472LY) the other day and it is advanced but also very expensive. It can be set as low as 30mA. I don't remember the upper limit, but you'll find the manual on Bender's website. You will need an external contactor (or suitable MCCB) and a current transformer."

 

[jbartos]

Comment: As it can be seen in the above posting, there are products that can satisfy the both, fire protection and personal safety, one at a time depending on their setting.

 

[ScottyUK]

I found some in Siemens catalogue NS PS 2001 on page 2/31 but they are only rated up to 63A. Might be a useful reference for the future. If you ring Siemens Automation & Drives, their applications engineers at Manchester (UK) are very helpful and will probably be able to assist.



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"Never look down any at anybody, unless you are helping them up."

Jesse Jackson.