Adding RCD to washing machine socket

[andyp]

I had the washing machine trip the rcd at the cu. It's a split load board and all kitchen sockets together so this meant the fridge also went off. Is there a switch (with built in RCD) I can add to the washing machine switch(the one above the counter)? Thx

 

[Murdoch]

Won't help - the RCD at the board will almost certainly trip first

 

[andyp]

Won't help - the RCD at the board will almost certainly trip first

Good point. Thx.

 

[Murdoch]

what you need to establish is how much your house is "leaking" and whether you have other problems.

This is why RCBO boards are far, far better

 

[Andy™]

you could use a 10mA RCD for the washer which will trip first at lower current however in case of a fault then chances are both will trip at the same time or just the RCD in the board

just another reason RCBO boards are better

 

[andyp]

you could use a 10mA RCD for the washer which will trip first at lower current however in case of a fault then chances are both will trip at the same time or just the RCD in the board

just another reason RCBO boards are better

Would that make it trip more often?

 

[andyp]

what you need to establish is how much your house is "leaking" and whether you have other problems.

This is why RCBO boards are far, far better

I would love to change them to rcbos. Until then maybe separating the fridge to its own circuit?

 

[Andy™]

Would that make it trip more often?

depends how much leakage it has

 

[binky]

I would love to change them to rcbos. Until then maybe separating the fridge to its own circuit?

that can be much easier said than done, but is alwys the ideal situation. Now I might be little out of touch due to retirement, but it was legit to have a fridge of freezer on a dedicated cct without RCD protection. I'm sure I will be corrected shortly if I'm wrong

 

[SPECIAL LOCATION]

that can be much easier said than done, but is alwys the ideal situation. Now I might be little out of touch due to retirement, but it was legit to have a fridge of freezer on a dedicated cct without RCD protection. I'm sure I will be corrected shortly if I'm wrong

You are thinking of the 17th ed Red book 411.3.3 where after stating 30ma RCDs are required for socket outlets it did have a note (b) about "Specifically labelled or otherwise identified socket outlet for a specific item of equipment"...

But this note was removed in the 18th ed Blue book..
Although it did allow for non-dwelling socket outlets that have a suitable risk assessment to have the RCD omitted.

 

[SPECIAL LOCATION]

I had the washing machine trip the rcd at the cu. It's a split load board and all kitchen sockets together so this meant the fridge also went off. Is there a switch (with built in RCD) I can add to the washing machine switch(the one above the counter)? Thx

If you are finding this "inconvenient" it could be argued that your installation does not comply with BS7671..?

As reg 314.1 goes back to the Red 17th ed book.. (or 314-01-01 prior to that)
which does require that the division of an installation should "Minimise Inconvenience" in the event of a single fault!!

And later in current regs 531.3.2 does suggest that consideration of RCBO's in domestic installations is a better solution than a dual RCD board!


Remember a 30ma must operate with a 30ma leakage.. but not with a 15ma leakage fault...
So anywhere from 16ma could be a tripping current..
also providing it operates within the max permissible time then it is good..

But not all manufactures devices operate at exactly the same, with the same trip current..
So if you put multiple 30ma RCD's in series it is pot luck as to which one will operate first!!

If wiring RCD's in series you generally need time-delayed RCD's to achieve any decent discrimination between devices.

 

[binky]

You are thinking of the 17th ed Red book 411.3.3 where after stating 30ma RCDs are required for socket outlets it did have a note (b) about "Specifically labelled or otherwise identified socket outlet for a specific item of equipment"...

But this note was removed in the 18th ed Blue book..
Although it did allow for non-dwelling socket outlets that have a suitable risk assessment to have the RCD omitted.

What about fixed equipment ie not a socket, but say a gas boiler?