100mA time delay rcd

[Paul17176]

Hello guys,

I'm after a bit of advice/opinion on this one.

A customer has a plumis mist sprinkler system that needs power.

I'm planning to stick in a separate unit, 100mA time delayed rcd as he wants the cables buried. If I just stick a mcb off of that would that be acceptable? It's not a TT system but it's what's suggested in the manufacturers instructions.

I'm not too clued up on time delay stuff so would appreciate any input.

Cheers

 

[Leesparkykent]

Hello guys,

I'm after a bit of advice/opinion on this one.

A customer has a plumis mist sprinkler system that needs power.

I'm planning to stick in a separate unit, 100mA time delayed rcd as he wants the cables buried. If I just stick a mcb off of that would that be acceptable? It's not a TT system but it's what's suggested in the manufacturers instructions.

I'm not too clued up on time delay stuff so would appreciate any input.

Cheers

For the cables to be buried at a depth below 50mm in prescribed zones you would require 30ma RCD protection

 

[Plonker 3]

Why 100mA?
What sort of cable are you using?
Buried in what?

 

[Plonker 3]

For the cables to be buried at a depth below 50mm in prescribed zones you would require 30ma RCD protection

Unless it comlies with 522.6.101

 

[Leesparkykent]

Automist an easy to install alternative to home fire sprinkler system
Automist an easy to install alternative to home fire sprinkler system
Automist is an easy to install alternative to home fire sprinkler system. Automist must be installed by one of our Accredited Installer Resellers and can take as ...

 

[Leesparkykent]

Unless it comlies with 522.6.101

Of course.

522.6.202 in BYB

 

[Paul17176]

Why 100mA?
What sort of cable are you using?
Buried in what?

Doesn't have to be 100mA tbf, couldn't find a time delayed 30mA rcd so was an assumption off of left field I guess. Was going to use t and e to a fused spur from the CU and buried in the wall.

 

[Paul17176]

Automist an easy to install alternative to home fire sprinkler system
Automist an easy to install alternative to home fire sprinkler system
Automist is an easy to install alternative to home fire sprinkler system. Automist must be installed by one of our Accredited Installer Resellers and can take as ...

Am just taking a feed to it

 

[Leesparkykent]

How far is the pump from the dis board?

 

[Plonker 3]

Doesn't have to be 100mA tbf, couldn't find a time delayed 30mA rcd so was an assumption off of left field I guess. Was going to use t and e to a fused spur from the CU and buried in the wall.

Well it needs 30mA rcd protection unless it complies with the reg I posted earlier. I would be looking at alterantive methods of installation to do away with RCD protection on a system loke this unless tye MI states it needs one.

 

[Paul17176]

How far is the pump from the dis board?

10-12 metres I'd say

 

[Paul17176]

Well it needs 30mA rcd protection unless it complies with the reg I posted earlier. I would be looking at alterantive methods of installation to do away with RCD protection on a system loke this unless tye MI states it needs one.

Yeah would be less hassle if he'd have it surface but doesn't want it. MI suggested time delayed rcd as only viable option if buried in wall.

 

[Leesparkykent]

Like Dillb said I would look at an alternative installation method so you don't have to put it on a RCD as the manufactures instructions state a time delayed RCD or no RCD protection.

 

[Plonker 3]

Plenty of other options to install it wothout RCD protection.

 

[Leesparkykent]

Buried SWA or buried Earthed metallic conduit for example.

 

[Paul17176]

Plenty of other options to install it wothout RCD protection.

Very true, will look to convince him it's the better option.

Thanks for your help fellas

 

[Paul17176]

Buried SWA or buried Earthed metallic conduit for example.

Hmm, hadn't considered a buried SWA. Thanks

 

[davesparks]

A 30mA time delayed RCD wouldn't help as the regulation requires a standard 30mA RCD.

Some foil screened (but not all) cables comply with the requirement for an earthed metallic surround/sheath or whatever. FP200 is one example of this

 

[Leesparkykent]

Hmm, hadn't considered a buried SWA. Thanks

The manufactures instructions say its 1700w so you could bury a 1.5mm 3core SWA and put it on a 10amp MCB. And a 1.5mm SWA isn't going to be the end of the world to bury lol

 

[Leesparkykent]

A 30mA time delayed RCD wouldn't help as the regulation requires a standard 30mA RCD.

Some foil screened (but not all) cables comply with the requirement for an earthed metallic surround/sheath or whatever. FP200 is one example of this

Just out of interest dave how would you earth the foil screen in FP200