Photo's of my CU change

[plugwash]

What was the motivation behind this CU change?

 

[Chri5]

The 2 colour warning label is too small.

Is there a sizing requirement ?

 

[Chri5]

Don't forget your periodic test label.

I'll get that sorted with the 'other' snags over the weekend.

Cooker cable looks thin in a C40 or is that an illusion

Your right, I'll be flamed for this (cooker, gas- pun)...... It's for a gas only cooker with electric controls- TLC delivery due later with a C20.

Wife needed to cook, and the oven won't start without the controls being live. Naughty, but required for 24 hours.

Finally, the C type RCBO's....are your EFLI's at the circuit destinations within spec for

Yes they are. I was also informed that C type is a preference for smoke alarms, since they would not nuisance trip (as much) due to fillament bulbs going.

I'll retest (again) later after the C20 turns up. Wylex B type RCBO's seem impossible to source easily, and the few times I've found any they have been £40+ each.



Jim wrote

The neutral numbers dont correspond with earths or lives

Please eloborate, I'm not sure what you mean.

 

[17thman]

yes 411.4.9 seems to give some people a reason to slap in an rcd to mask a poorly designed or functioning circuit.

 

[Cremeegg]

The Big Red Book offers varying requirements for label sizes. Well, in fact, not the label size itself but the size of the characters on the label are specified for some but not all.

514.10.1 - voltage - no sizes specified
514.11.1 - isolation - no sizes specified
514.12.1 - periodic inspection - characters no smaller than those in book
514.12.2 - RCD - characters no smaller than those in book
514.13.2 - earthing - characters no smaller than those in book
514.14.1 - colours - no sizes specified
514.15.1 - dual supply - no sizes specified

Perhaps such inconsistency will be removed in the first amendment?

 

[EddyP]

Nice and neat.

Our of interest does the bus bar to the RCBOs and the two feeds to the RCDs all share the same terminal?

 

[333rocky333]

I've noticed that you have sleeved your RCBO earth connections in green and yellow. I do this too, but I was wondering if this is actually required, or whether in fact they should be cream? If so, why don't the manufacturers do this?

Mk used to

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• 333rocky333
• 26 Jul 2008
• 2

 

[ban-all-sheds]

That might be badged MK, but it's made by Siemens.

 

[kevin1234]

i was wondering what circuits would not be RCD protected in a new mains board with the 17th regs?

 

[JonoPashley]

Ones used to supply fixed equipment, which are buried deeeper than 50mm in the wall or have earthed mechanical protection

 

[hairyben]

Did the original CU have the correct busbar?

IMO being a recent wylex it offers the easy upgrade path of swapping the non RCD MCB's for RCBO's, provided they fit in the enclosure, instead of buying/fitting a entire new unit. Unless of course you needed the additional spare ways.

 

[rebuke]

i was wondering what circuits would not be RCD protected in a new mains board with the 17th regs?

I re-did my house CU, and the circuits without RCD protection are:
Supply to shed (going to be an RCD main switch out there when I eventually wire it)
Supply to immersion heater (I was advised it was sensible to avoid RCD protecting this, still not sure though, might put it on an RCBO at some point)
Supply to smoke alarms
Supply to emergency light next to CU
Supply to burglar alarm
Supply to UPS for servers (via a fixed IEC cable)

All the non RCD protected circuits are obviously not buried at less than 50mm in a wall etc etc...

 

[RF Lighting]

Would your em light not be better off on the same circuit as the lights in that room?

Otherwise, if the local lighting circuit trips, you'll be left in darkness with the em still charging away.

 

[rebuke]

I thought about that, but in the end decided not to - it's a switchable maintained emergency, with the switch next to the CU, so I can turn it on if the downstairs lights fail.

My rationale was that if I'm working on light fittings downstairs, then I might want to leave the circuit off for longer than the battery would last, at which point I'd get no lighting whatsoever. I suppose an ideal solution would be to set it up with a changeover switch so I can choose where it's supplied from - leaving it on the lighting circuit normally, and switch to the separate one if needed. I'm not sure on the regs on this though, since it would create something requiring isolation at multiple points etc...