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

 

[Spoon]

If only the workers of the factory are using the ramps and sockets then there is no need to add RCD's. I'll find the reg.

 

[Paultrim123321]

Are the non electrical workers(fitters) classed as competent users of electrical equipment? Brings out the old debate about competency? I'd argue not and RCD protection would be beneficial? But that's my opinion?
As for the lift, you need to refer to the installation methods etc

 

[snowhead]

If only the workers of the factory are using the ramps and sockets then there is no need to add RCD's. I'll find the reg.

If H&S want RCD then they won't settle for less regs or no regs.

For 3 phase RCBO see;

http://www.modbs.co.uk/news/archivestory.php/aid/11344/3-phase_RCBO_for_Eaton_92s_Memshield_3_.html

 

[snowhead]

Are the non electrical workers(fitters) classed as competent users of electrical equipment? Brings out the old debate about competency? I'd argue not and RCD protection would be beneficial? But that's my opinion?
As for the lift, you need to refer to the installation methods etc

It's Skilled or Instructed not competent.
A cleaner can be classed as Skilled or Instructed.

Yes RCD would still be beneficial tho.

 

[Spoon]

If H&S want RCD then they won't settle for less regs or no regs.

Well if they insist then let them have the RCD's. You can point out that according to reg 411.3.3 its not really needed as the workers should be classed as either skilled or instructed.

 

[Parker27]

First thing I would do, is find out what happens if you loose power to the lifts, does it drop?

What you could do is mount the 3 phase RCD's in adaptable boxes at the point where the ramp is plugged into the socket, and wire the RCD's into the sockets.

 

[snowhead]

First thing I would do, is find out what happens if you loose power to the lifts, does it drop?

No they don't drop.

 

[Dave 85]

Well if they insist then let them have the RCD's. You can point out that according to reg 411.3.3 its not really needed as the workers should be classed as either skilled or instructed.

Thanks Spoon. This did occur to me when discussing it and I did point out to them that RCD's in commercial premises were somewhat of a grey area. On the other hand if they insist on having the work done then I am happy to do it for them.
I may have to go back and do a bit of further investigation before quoting. I didn't for example, check weather the ramps take a neutral or just 3 phases.
It does make me laugh how these so called 'health and safety experts' can walk around wielding the power to make decisions well beyond their obviously limited knowledge.

 

[Spoon]

No they don't drop.

It would be a bad design if it did. Might be fun to watch, as long as you are not under it...

 

[Darkwood]

First thing I would do, is find out what happens if you loose power to the lifts, does it drop?

What you could do is mount the 3 phase RCD's in adaptable boxes at the point where the ramp is plugged into the socket, and wire the RCD's into the sockets.

So in a power cut all mechanics get crushed under their work hhhhmmm.. think that won't be the case!

 

[Spoon]

Thanks Spoon. This did occur to me when discussing it and I did point out to them that RCD's in commercial premises were somewhat of a grey area. On the other hand if they insist on having the work done then I am happy to do it for them.
I may have to go back and do a bit of further investigation before quoting. I didn't for example, check weather the ramps take a neutral or just 3 phases.
It does make me laugh how these so called 'health and safety experts' can walk around wielding the power to make decisions well beyond their obviously limited knowledge.

Anytime mate. As snowhead has said pointed out, H&S may insist, so just fit them. Some of the H&S people are ok but some just love the power that they have.

 

[Spoon]

So in a power cut all mechanics get crushed under their work hhhhmmm.. think that won't be the case!

it save you making them redundant...

 

[Knobhead]

Sockets I can understand RCD’s. Surely the ramps are fixed, it just doesn’t make any sense.

 

[Darkwood]

431.3.3 - note1
314.1(iv)
531.2.4

If the ramps are routinely serviced and are supplied via a fixed outlet not a plug/socket affair then their is no need for rcd protection, if however the ramps are portable and the run 400v flexes across the workshop floor then the socket outlets require rcd protection IMHO... if the motors on the ramps are VFD controlled then the above regulations will be contravened and alternative methods of powering the units need finding so flexes dont run across workshop.

The H&S quangos are a law unto themselves and unless you state throwing relevant reasons and regulations at them they dont want to know .... id also put to them that all cost incurred due to nuisance tripping of RCD's will be passed to them as they are stipulating measures beyond BS7671..... if they agree to anything you put forward ask for it in writing too as an amendment to their original wishes.