RCD protection on multiple 3 phase machines

[Dave 85]

Hi guys

Just wanted to pick your brains on the following...
I've been doing some work in a Jaguar dealership and they've had a health and safety guy come around and recommend that all existing socket circuits and 3 phase car ramps should be given RCD protection. I have been asked to quote for said work.

Now we are looking at 10 3phase ramps and around 12 socket circuits fed from 4 different DB's (old brown square D ones) which are all 20 odd meters apart.

Ideally I wanted to replace at least 3 of the DB's so I could put RCBO protection on all socket circuits but I'm not sure what to do with the ramps....as far as I'm aware you cant get 3phase RCBO's??? and having an RCD main switch on each board seems like a very poor option.

One though is to replace the DB's, keep MCB's on the ramps but then install remote RCD isolators for each ramp. Obviously I'm trying to make this cost effective.

Any advice would be much appreciated.

Thanks

 

[Dave 85]

Cheers for all the advice lads. I have quoted to install a couple of single phase C/U's with RCBO's to cover the socket circuits and a 3phase RCD in an enclosure for each car ramp. I'm gonna take another look before I agree to anything fully though.
With regards to weather or not the stuff should actually have RCD....interesting debate but considering they're insisting they want it I don't really see it as being my place to tell them they cant have it.

 

[Darkwood]

As the OP hasn't given enough detail about the full set-up there may be good reason for them to stipulate RCD protection ... like lack of maintenance or age and condition of ramps ...i hope he considers this before storming in like a bull in a china shop.

As ive said before the H&S asking for rcd protection can only be to the isolators and thus reasoning under BS7671 needs to be established.

They cant request rcd protection for the ramp under BS7671 because its falls outside the BS7671 but they may be utilising other regulations for which the ramps fall under but firstly i would be asking for specific regulations and codes of practice as putting a rcd on a 4motor ramp with inverter control would be asking for trouble even without inverter run motors their could be issues.

If the ramps are on plug tops then yes the sockets should be rcd covered as anything can be plugged in and run around the garage prone to damage but if hardwired id be asking a few questions.

 

[Darkwood]

Cheers for all the advice lads. I have quoted to install a couple of single phase C/U's with RCBO's to cover the socket circuits and a 3phase RCD in an enclosure for each car ramp. I'm gonna take another look before I agree to anything fully though.
With regards to weather or not the stuff should actually have RCD....interesting debate but considering they're insisting they want it I don't really see it as being my place to tell them they cant have it.

Not saying they can't have them just ask under what code of practice or regulation they are requesting rcd protection and also fitting rcd's may promote nuisance tripping which would be in breach of BS7671 ... are the ramps hard wired to isolators or direct to DB or are they on plug/socket assemblies?

 

[joel89]

surely the ramps have to be checked every 6 months anyway under LOLER ?? and theres no trailing cables like off a 13a sockets, seems over the top and pointless RCD'S on ramps.. what next?

 

[telectrix]

surely the ramps have to be checked every 6 months anyway under LOLER ?? and theres no trailing cables like off a 13a sockets, seems over the top and pointless RCD'S on ramps.. what next?

hard hats for motor mechanics, just in case a jubilee clip falls on the head.

 

[Brightspark2]

Ive had this exact same scenario about 6 months ago, an 'engineer' from there European head office visited and demanded all sockets including 32A,63A, sockets used for welding etc etc all be protected by RCD. We informed them this was not necessary but the 'engineers' word was final. He wanted them fitted. Its ok saying argue this and that but at the end of the day if we didnt do it they where just going to get someone else to do it and we'd lose the contract. So we got it done.

Where we couldnt install RCBO's we did as you say and installed RCD sockets or enclosures next to the equipment. Dont forget if there's no neutral you'll need a resistor to get the test button to work on the RCD.

 

[Dizzy_Maskell]

Well said think you need to read your copy of the regs
If you have one ?????

 

[netblindpaul]

1st confession, I lost the will to live reading all replies.
The H&S person is DEFINITELY not from Her Majesties Health & Safety Executive.
I also very much doubt they are competent to comment on such things.
IF the ramps are bolted to the floor, and the wiring to them meets the requirements for BS7671 why RCD.
I can't understand why they are on plugs & sockets, unless they are portable which is a different kettle of fish.
Change the plugs & sockets to isolators and hard wire them, no need for RCD's.

If there is info given in the thread after page 2 I ain't read it the forum crashed so I could not be bothered!

I only know a handful of H&S consultants who are electrically competent, out of the 100's I know of.

 

[Brightspark2]

hard hats for motor mechanics, just in case a jubilee clip falls on the head.

It just gets worse doesnt it. They need to keep thinking of new rules to keep them in a job though!...

 

[davethsparky]

Same set of toolheads that banned conkers i bet!

Who banned conkers? you cant blame the HSE for that one.

Have a look here: Myth: Kids must wear goggles to play conkers

Just look through all the 'myth of the month' pages and the h+s mythbuster cases, its a very sad situation when the HSE are having to waste their time trying to undo the damage that the mini hitlers on a power trip have caused.

I think as far as the HSE go and the actual laws and requirements it is mostly quite sensible, its the idiots that misinterpret it all and shout loudly about how everything is banned that have ruined it.

 

[Tiny Spark]

So are kids still aloud to play British bulldog then?
That was a staple part of my break times entertainment LOL

 

[davethsparky]

Kids are doing whatever they want really, as kids have always done!

Doesn't take a genius to work out that the 'Health and safety AT WORK act' doesn't apply to kids who are a good few years off starting their first jobs!

What does in fact apply is the insurance company and teacher's massive fear of the compensation culture and the ambulance chasing blood sucking vampires (lawyers)

 

[netblindpaul]

Incompetent H&S advisor's also?...

 

[Engineer54]

Sounds to me as yet another reason, why you ''Don't'' see UK H&S Officers employed on any overseas contracts!! lol!!

 

[Marvo]

If the machines are on plug and socket then my local regs would require RCD protection. This is because generally machines on plugs are mobile with trailing cables therefore higher risk. If installed via an isolator that requirement falls away unless there's another special risk involved.