Does a CU swap require a full initial verification on all circuits before it can be energised?

[BrianM]

To my understanding it would be ideal to test and inspect before energisation, but it isn't 100% necessary. If it leaves a client without power, it breaches health and safety (no power to safety services etc) or inconveniences them I'd have thought it would be reasonably practicable to turn on the juice and test ASAP.

 

[mainline]

To my understanding it would be ideal to test and inspect before energisation, but it isn't 100% necessary. If it leaves a client without power, it breaches health and safety (no power to safety services etc) or inconveniences them I'd have thought it would be reasonably practicable to turn on the juice and test ASAP.

You couldn't really have any confidence in that circuit/s unless you do.

In the case of a Cu change, for instance, why would you not test before energising ?
The power is only going to be going off again when it comes to testing, which will end up having no power for a longer time overall, unless you don't bother testing at all.

 

[DPG]

To my understanding it would be ideal to test and inspect before energisation, but it isn't 100% necessary. If it leaves a client without power, it breaches health and safety (no power to safety services etc) or inconveniences them I'd have thought it would be reasonably practicable to turn on the juice and test ASAP.

You're not really going to energise the system without doing the testing though are you. Surely the customer has been told that the power will be off during the CU change??

Yes, the testing is necessary.

In any case, you'd have to switch the power back off to do the dead tests, so what's the advantage of rushing to get the power back on before this?

 

[Dustydazzler]

How do you 'Change' a consumer unit without turning off the power ? Ok doing a little bit of dead testing might and an extra 25mins to the power being off but thats about it on an average board change. You could just switch everything on (the Bang Test) and hope for the best, but that is not the right way Imo

 

[westward10]

Explain health and safety (safety services).

 

[BrianM]

Ok,

To explain the situation... it's 4am, The electrician has been working since 8am. Beginning the testing process will be dangerous as the electrician is too tired to continue. The CU is installed properly so won't go bang an inspection of the CU shows this. If it is not energised there are severe disruptions... ambulance access, police access, security patrols are disrupted etc and the fire alarms & emergency lighting are affected to the premises.

Like I said, ideally, it would be tested but in this situation... but the regs just say reasonably practicable.

 

[mainline]

Ok,

To explain the situation... it's 4am, The electrician has been working since 8am. Beginning the testing process will be dangerous as the electrician is too tired to continue. The CU is installed properly so won't go bang an inspection of the CU shows this. If it is not energised there are severe disruptions... ambulance access, police access, security patrols are disrupted etc and the fire alarms & emergency lighting are affected to the premises.

Like I said, ideally, it would be tested but in this situation... but the regs just say reasonably practicable.

I should have been tested before the Cu was fitted ?

 

[DPG]

Ok,

To explain the situation... it's 4am, The electrician has been working since 8am. Beginning the testing process will be dangerous as the electrician is too tired to continue. The CU is installed properly so won't go bang an inspection of the CU shows this. If it is not energised there are severe disruptions... ambulance access, police access, security patrols are disrupted etc and the fire alarms & emergency lighting are affected to the premises.

Like I said, ideally, it would be tested but in this situation... but the regs just say reasonably practicable.

That's quite a specific example!

For such a critical installation then the job has been badly planned. And the bang test is certainly not appropriate.

 

[westward10]

Ok,

To explain the situation... it's 4am, The electrician has been working since 8am. Beginning the testing process will be dangerous as the electrician is too tired to continue. The CU is installed properly so won't go bang an inspection of the CU shows this. If it is not energised there are severe disruptions... ambulance access, police access, security patrols are disrupted etc and the fire alarms & emergency lighting are affected to the premises.

Like I said, ideally, it would be tested but in this situation... but the regs just say reasonably practicable.

Where is this DB.

 

[Dustydazzler]

As above planning planning planning

vital circuits could be tested and re-energised first then non vital circuits added later ?

 

[BrianM]

That was my thinking, system had periodic inspections and the initial verification.

Job was planned by the bosses, timing and planning not up to the electrician.

Advice to next shift on at 8am to test critical systems given. Client happy to wait a further 4 hours. They neither tested nor re-energised. Left no power for 2 days.

When it was tested... and re-energised... no bang.

Has caused a bit of a thing at work. Just wondering which way to go.

 

[westward10]

I wouldn't be worrying about it as it is probably no more dangerous than prior to the board change so provided going forward it is tested I see no big issues.

 

[BrianM]

That was my thinking, system had periodic inspections and the initial verification...

...Has caused a bit of a thing at work. Just wondering which way to go.

The reason given for not doing anything was there was a C3 fault. The board installed was smaller than the original so conduit no longer fitted. (Not installers choice) it was planned to be boxed in. This was predicted and reported to management. Knockouts were given grommet strip edging.

Tbh... I'd have tested it, powered it up and said get the joiner in ASAP. (I think the 2nd shift are just bullying the original electrician)

 

[littlespark]

The C3 where conduits no longer line up with knockout holes…. Is there a gap now with basic insulation showing between the conduit and the DB?

Could have been solved with a bit of trunking?

 

[Dustydazzler]

The C3 where conduits no longer line up with knockout holes…. Is there a gap now with basic insulation showing between the conduit and the DB?

Could have been solved with a bit of trunking?

Yes we used to run some galv trunking horizontal butted up to the board and take the conduits into the trunking which means no gaps or mis-aligned old conduits in the new DB

 

[snowhead]

To explain the situation... it's 4am, The electrician has been working since 8am.

So the Electrician has been working continuously for 20hrs and is then starting or completing a C.U change?

Powering up untested because it's inconvenient / potentially a H&S issue is not a valid reason.
It could be a bigger H&S issue if there was a fault that caused injury or worse.
Just because it had had previous inspections doesn't mean at the end of the CU swop that it doesn't have any faults, especially given how long the Electrician had been working.

There's already a serious H&S issue with the electrican working 20hrs.

 

[BrianM]

The C3 where conduits no longer line up with knockout holes…. Is there a gap now with basic insulation showing between the conduit and the DB?

Could have been solved with a bit of trunking?

Agree. Conduits line up perfectly. There's about a 9-10mm gap. It's boxed in with no stress or strain & no access. Essentially the conduit is rendered null & void?

 

[BrianM]

So the Electrician has been working continuously for 20hrs and is then starting or completing a C.U change?

Powering up untested because it's inconvenient / potentially a H&S issue is not a valid reason.
It could be a bigger H&S issue if there was a fault that caused injury or worse.
Just because it had had previous inspections doesn't mean at the end of the CU swop that it doesn't have any faults, especially given how long the Electrician had been working.

There's already a serious H&S issue with the electrican working 20hrs.

Ok... maximum security prison. Various high risk prisoners topping themselves and stabbing each other... yes planning should have been way way better... but loss of power was a real H&S risk. Refusing to test it or put it back on for 2 days over a C3 fault? The more I think about it the more I think they should have had the guys back and sorted something out.

 

[DPG]

I still don't get how the job ended up going the way it did. Was it badly planned? Were there too few staff doing the job?

What if it had gone wrong due to lack of time/testing?

Edit: I realise it's easy for me to criticise while I'm sat here drinking Old Peculier!

 

[BrianM]

I still don't get how the job ended up going the way it did. Was it badly planned? Were there too few staff doing the job?

What if it had gone wrong due to lack of time/testing?

As far as I can tell mistakes on both sides. Electrician thought 6-8 hours to install and test. Had to put in extra metal conduit for fire alarm because board had to be moved further left to align the conduit. Board supplied had incomer on wrong side and most CPD's supplied were wrong too. True nightmare job. The bosses son organised it and was assisting (office admin/wannabe apprentice) apparently he just sat down and did next to nothing. Didn't even pass tools.