RCD/RCBO placement order

[J'adore electrics]

Hi guys

I’ve tried researching the orders of RCD/RCBO placement in relation to type.

Am I correct in saying installing an AC type upstream of an A type can still blind the A type?
And is this the case in reverse?

A TYPE upstream of an AC type?

Appreciate there has prop been a discussion on this previously but easier to ask again.

Thank you in advance guys.

 

[Sidewinder]

The correct order is:
Supply>B>F>A>AC>Load
Load must not have any DC components to its leakage or fault current.
Else:
Supply>B>F>A>Load
This allows for up to 6 mA of pulsed DC leakage.
Any more or steady DC and you are looking at:
Supply>B>Load
If you have High Frequency components but no more than 6 mA of pulsed DC, and no steady DC then:
Supply>B>F>Load

Doepke provide sound information for the selection requirements of RCDs on their website.

 

[Murdoch]

^^ very informative

 

[binky]

The correct order is:
Supply>B>F>A>AC>Load
Load must not have any DC components to its leakage or fault current.
Else:
Supply>B>F>A>Load
This allows for up to 6 mA of pulsed DC leakage.
Any more or steady DC and you are looking at:
Supply>B>Load
If you have High Frequency components but no more than 6 mA of pulsed DC, and no steady DC then:
Supply>B>F>Load

Doepke provide sound information for the selection requirements of RCDs on their website.

I'm trying to think where DC leakge would be an issue?

 

[Sidewinder]

Switch mode, inverters with dc bridge, anywhere there is a dc source generated from the mains which can either leak or cause a dc offset in the ac mains.

 

[binky]

Switch mode, inverters with dc bridge, anywhere there is a dc source generated from the mains which can either leak or cause a dc offset in the ac mains.

Doesn't sound like anything I've ever put in a house...

 

[kerching]

I'm trying to think where DC leakge would be an issue?

I think TESLA own brand chargers need type B....
But as I know nothing about this witchcraft I may well be wrong

 

[Sidewinder]

Doesn't sound like anything I've ever put in a house...

Washing machine, LED lamp, AV equipment, IT equipment, networking equipment, solar inverter, microwave oven, anything with electronics inside it.

 

[binky]

Washing machine, LED lamp, AV equipment, IT equipment, networking equipment, solar inverter, microwave oven, anything with electronics inside it.

Ah, so you are talking about anything that has smoothing electronics and leaks a little down the earth.

 

[Murdoch]

The bottom line with this knowledge is that so few people know this, and I can’t see this knowledge increasing anytime soon.