Industrial EICR

[Aevo69]

I know this is not a domestic question but thought I'd give you guys a go, recently been doing a 1940's built large factory with wiring from all decades. There is roughly 130 D.Bs and C.Us mostly carrying bs3036 fuses spread over five transformers. The problem I am having is that through out the factory there is a lot of three phase ccts feeding isolator which from this point is split in to single phase lighting ccts. from a report point of view what code would you give to this if any? would you deem this has unsatisfactory?

for me I would say that this does not comply with reg (314.4).
what do you think guys.

 

[ricicle]

The final circuits are connected to a distribution board it's just that they pass through an isolator !
I can't see a problem as long as all other factors are ok (correct neutral orientation, cable sizing/fusing etc)

The only issue is if someone turns the isolator off by mistake how much lighting do you lose and what is the risk due to the factory processes ? Is there sufficient emergency lighting ?

 

[Aevo69]

The final circuits are connected to a distribution board it's just that they pass through an isolator !
I can't see a problem as long as all other factors are ok (correct neutral orientation, cable sizing/fusing etc)

The only issue is if someone turns the isolator off by mistake how much lighting do you lose and what is the risk due to the factory processes ? Is there sufficient emergency lighting ?

I see your point, but lets say someone needs to add a light to a row, pulls the 3036 fuse which in turn leaves two phases live, there would still be a back feed at the neutral once disconnected, with it been a shared neutral.

 

[ricicle]

Ah - you didn't mention one neutral. As there are 3 seperate fuses then there should be 3 neutrals. It could be argued that anyone working on one circuit should isolate using the 3 pole iso. but that could not be relied upon to happen.

 

[Aevo69]

Ah - you didn't mention one neutral. As there are 3 seperate fuses then there should be 3 neutrals. It could be argued that anyone working on one circuit should isolate using the 3 pole iso. but that could not be relied upon to happen.

Sorry, yeah thats my problem with how they have done it I could except it if they had put some kind of lighting panel in fed that with a three phase supply and then had control gear for each circuit. looks like a lot of code 2's to me.

 

[Spark123]

As long as warning labels, diagrams etc are in place I don't see a major issue. Are the neutrals split at the isolator or is there just one neutral from the isolators up to the lights?

What are the fault levels like at the boards? In factories with their own substation transformers I tend to see BS88 fuses more than rewirable fuses.

 

[Adam_151]

Also bear in mind a lot of the 3ph 3036 boards in use, MEM, bill, etc had asbestos flash pads behind the fuses

As to the lighting circuits, you have to decide whether it is one three phase circuit serving many fittings across all three phases with one neutral (acceptable as long as there is an isolator to cut all three phses simutaniously). One would hope that from the board labeling that it is clear that it is a three phase circuit, however

Or whether it is simply a group of single phase circuits with a shared neutral (which is not acceptable)

 

[Aevo69]

Also bear in mind a lot of the 3ph 3036 boards in use, MEM, bill, etc had asbestos flash pads behind the fuses

As to the lighting circuits, you have to decide whether it is one three phase circuit serving many fittings across all three phases with one neutral (acceptable as long as there is an isolator to cut all three phses simutaniously). One would hope that from the board labeling that it is clear that it is a three phase circuit, however

Or whether it is simply a group of single phase circuits with a shared neutral (which is not acceptable)

Sounds like we're both on the same track ere, when I ring the NIC all I get when they don't know the answer is "it's to your own discretion". They are asbestos lined and have issued a code 3 for that stating a modern equivalent is needed to replace the out dated d.b visual inspection only due to asbestos.

I think if it had a 3 phase mcb where all phases would be disconnected I would turn a blind eye to it, like you said as long as it was labelled up to the eyeballs. But unfortunately at the moment I can not trust any person to remove all three fuses regardless to how many warning signs and labels I install and or locate the isolator. Code 2 would you say. Ps thanks for replying.

 

[SaladFingers]

Also bear in mind a lot of the 3ph 3036 boards in use, MEM, bill, etc had asbestos flash pads behind the fuses

Are you sure they're 3036 not BS88s? I'm familiar with your situation.

 

[Adam_151]

How would you consider a three phase submain running from such a board? would you consider that ok?