RCD or Not

[plugsandsparks]

Listen to IQ. Even if this establishment is not directly under authroity control this establishment may be using other internal guidelines which i would jump on the back off. End of the day, it costs what it costs. RCDs are here to stay so may as well get used to them.

 

[mogga]

Sounds like you NEED to get someone who knows what they are doing to plan and execute the job as you yourself admit not being competant nor qualified 94.4% means NOT Qualified doesnt it ?

 

[electromonkey]

Surface mounted install you say?

Unless it's on a TT then an RCD isn't necessary, would that be right folks?

 

[D80]

For socket outlets not in use by skilled or supervised persons RCD protection is needed.

 

[electromonkey]

I'm assuming metal conduit here as the OP says it's surface mounted?

What say you Steve?

 

[simonspark]

Sounds like you NEED to get someone who knows what they are doing to plan and execute the job as you yourself admit not being competant nor qualified 94.4% means NOT Qualified doesnt it ?

99.4%. Did I put .6?

 

[simonspark]

All surface mounted via trunking. No concealed wiring. And despite some of the slurs, I do know what I am talking about. And I think RCD's are fantastic. But...... I am sure that if equipment that can be sensitive to the protection that an RCD provides, as long as it is clearly labelled to state this fact,and it is not supplied via a TT sysyem, then it does not contravene the regs.

 

[simonspark]

Oh yeah. And also that there is provision elsewhere for RCD protected outlets.
I will have a chat with the NIC tomorrow. See what they say. If it's ok with them, then it's ok with me

 

[Welchyboy]

All surface mounted via trunking. No concealed wiring. And despite some of the slurs, I do know what I am talking about. And I think RCD's are fantastic. But...... I am sure that if equipment that can be sensitive to the protection that an RCD provides, as long as it is clearly labelled to state this fact,and it is not supplied via a TT sysyem, then it does not contravene the regs.

if your goin to omit RCD protection you will need it in writing from the client saying they are adequately supervised, to cover ur ---, or if any thing happens it will be ur word against theirs and you will likely cop it
think about these sort of things before you think about the cost of the job

also why are people even talking about ring circuits and 4mm cables???? WTF!!

surely earth leakage is your limiting factor in this equation so why not 16a/2.5mm RCBO radials with a 4 mm earth run back on each circuit to provide your high integrity earthing, supplying no more than 4 PC units per circuit, job done!

i seriously wouldnt chance loading an rcd up with any more likely load than 15mA as most i have ramp tested in the past will trip at around 20-25mA

 

[simonspark]

Final word. Mogga, you have made me smile. Calm down young man!!

 

[simonspark]

Some sense from Welchyboy. The reason that I cannot do what you have suggested is down to the fact that is an unbelievable building to work in. I am really limited to where I can drill for cable penetration. About 20mm! I considered what you suggested, but without destroying half the room, it aint practicle. But thanks

 

[plugsandsparks]

When i am looking at this type of problem i weigh up pros and cons of RCBOs in CU and RCD sockets. I have even changed my mind mid - install when the wiring problems or not come into play. What i dont do is say, " oh well - too hard, so lets drop the RCD and look for a reg. Computers are improving and their leakage is getting lower from what i can make out but the standards and expectations of the clients and authorities is increasing so .... in general if i fit a socket, one way or another there will be RCD protection

 

[D80]

2 radials would be better than 1 ring if on RCBO's. Still a bit lost on what you meant by IT system in origination post, I'd assume you meant high integrity earthing though.

 

[Welchyboy]

sorry just a correction on my part - if your wiring is all enclosed then your return CPC can be equal to that of your circuit CPC, and yes RCD socket outlets would also be another option

again its juggling regs with cost to find a mutually agreeable solution!

one thing you dont wanna do is do one big ring main with no RCD protection as if this is later pulled up and they want RCD.......ur in the brown stuff my friend