chouchou
Member
Does anyone know where I can buy 12V RCD?
Thanks
Thanks
12V RCD
- Thread starter chouchou
- Start date
Vara
Well-Known Member
Is there such a beast? And why would anybody want one?
bendyone
Well-Known Member
If it is 12v DC an RCD will not work. If AC any RCD will work it is not voltage dependent.
st599
Well-Known Member
12V d.c. can't be used with an RCD
Appleyard
Well-Known Member
Are you sure that it's an RCD you are after? Could you be getting it confused with an MCB (minature circuit breaker)? However I don't know if these are available in 12V
VicMallows
Well-Known Member
If it's really MCBs you're after, as suggested by JAMESMAR, they are readily available. All usual types are not voltage dependant for operation (though they will have max voltage and current ratings which will differ for AC and DC). Main choices are between thermal and magnetic types (or combination of both).
I can't see any theoretical reason why one couldn't design a DC Residual Current Device (RCD). It would have to work quite differently from a 'normal' RCD though, requiring shunts in both the positive and negative feeds (with associated voltage drops which could be large given the sensitivity you would presumably require). No such commercial device exists to the best of my knowledge.
Probably easier ways to achieve whatever it is you are thinking of /forums/images/graemlins/smile.gif
Vic
I can't see any theoretical reason why one couldn't design a DC Residual Current Device (RCD). It would have to work quite differently from a 'normal' RCD though, requiring shunts in both the positive and negative feeds (with associated voltage drops which could be large given the sensitivity you would presumably require). No such commercial device exists to the best of my knowledge.
Probably easier ways to achieve whatever it is you are thinking of /forums/images/graemlins/smile.gif
Vic
Graham_Wright
Well-Known Member
Interested to know why not. Opposing magnetic fields which cancel when out and back currents are equal. Or is it the reaction circuit breaker that causes non operation on DC?
halcyon
Well-Known Member
It's possible to make one with no volt drop, but why?.
Only use I can see is to check for leakage in the DC system and possible electolytic corrosion.
Brian
Only use I can see is to check for leakage in the DC system and possible electolytic corrosion.
Brian
bendyone
Well-Known Member
In gerneal DC will not induce the required magnetic out of balance needed to trip the RCD
DaveS
Well-Known Member
Why?
VicMallows
Well-Known Member
Agree with 'Why?' ... can only think Chouchou is concerned with electrolysis issues.
Considered the Hall Effect (or similar) route, but concluded unlikely to achieve the required sensitivity (surely way under 30mA if electrolysis is the issue?) when also considering the likely current draw device must accept.
Have been out of the area for some years, so will be interested if there are now approaches that would now work in practice. (PM if you think getting too technical for general interest).
Vic
Considered the Hall Effect (or similar) route, but concluded unlikely to achieve the required sensitivity (surely way under 30mA if electrolysis is the issue?) when also considering the likely current draw device must accept.
Have been out of the area for some years, so will be interested if there are now approaches that would now work in practice. (PM if you think getting too technical for general interest).
Vic
