I would like an opinion on two things I am concerned about.

[Davisonp]

Hi,
I would like an opinion on two things I am concerned about.

Background.
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I have done some work for a church that has bought a derelict farm. They demolished some of the derelict buildings and put up wood structures on the same footprint in 2012. The builders produced no test cert's and appear to have used the flash bang method of initial testing.
At the meter for the site, there is currently a single phase 100A fuse to feed the whole site (although there is a 3 phase cable buried and in place for when the church want to utilise it). This 100A supply is split by a Henley block and supplies 3 boards (Via Switched Fuses) in 3 buildings. The sub board I have concerns about is in a 2 room Church/Barn in the centre of the complex (the big room can seat 80 people but was outgrown in a couple of years).

My concerns.
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1) The board is a 100A plastic RCBO board, and circuits run from this board supply power for 4, 9A space heaters for two tent, 3, 8A urns, an out house with an 8A washer/dryer, 40A supply to a large park home caravan and a supply to a smaller park home caravan as well as lighting to the barn, smaller room and two tents. The caravans have log burners for heat but showers and cookers are all electric. I suspect the 100A Main Switch may be overloaded on occasions for short lengths of time.
If I had done an EICR, I would have coded this as a "C3" and my recommendation to the church when I was working on the farm was to replace the existing CU with a 3 phase metal CU. Even as an adapted single phase supply, the three 100A main switches would never be overloaded. The circuits can be organised so if the 3 phase supply is installed at a later date it is just a change to the intake nothing else needs to change.

2) There is a SWA incoming to the consumer unit, and 5 SWA outputs. The only SWA cable with any support is the incoming cable where there is one attempt to hold the cable in place but it has slipped and several of the SWA cables are pulling on the plastic casing and distorting the casing. This distortion I would code as a "C2". In my opinion, it may be OK and could last many years, or something could give next week as the strain is clear and constant. I have raised this with the church and made them aware few years ago and recommended the 3 phase metal consumer unit more appropriate for SWA terminating.

Reason for this Post.
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Now, I have moved on and taken a full time job for a housing association, and the church have found an "Old Boy" electrician close to retirement who has looked at the consumer unit and unsupported SWA cables and told them "It's fine, don't worry about it", and don't worry about EICR's.

I would like opinions so I can forward a link to the church site manager and show what the experienced electricians here think.

 

[Ian1981]

Can I ask , Are you coding the fact that there is a plastic CU in place as a C3?

 

[telectrix]

that is a right mess.

 

[Davisonp]

Can I ask , Are you coding the fact that there is a plastic CU in place as a C3?

Can I ask , Are you coding the fact that there is a plastic CU in place as a C3?

No, as space heater and water heaters get turned on together in the morning, I suspect the 100A switch will be overloaded for a while when the tents are in use. There is a very heavy power draw first thing.

 

[barninks]

ooooohhh that is a mess
i'm not a fan of unsupported SWA if i'm honest
But instead of spending time and effort sorting everything out i would go down the route of trying to get a nice 3ph board in with a bit of containment and support.
If that fails, at least get some cleats on the SWA
If you had a clamp meter you could try and get a reading on the incoming when it is at max draw. would be interesting

 

[davesparks]

No, as space heater and water heaters get turned on together in the morning, I suspect the 100A switch will be overloaded for a while when the tents are in use. There is a very heavy power draw first thing.

In an existing installation the best thing to do would be a load study carried out over a couple of weeks. Then you have proof of what is going on rather than just suspicions.

 

[Davisonp]

In an existing installation the best thing to do would be a load study carried out over a couple of weeks. Then you have proof of what is going on rather than just suspicions.

Thank you,
It is the unsupported SWA distorting the enclosure I am most concerned with, and the fact they have been told it is OK.

 

[davesparks]

Thank you,
It is the unsupported SWA distorting the enclosure I am most concerned with, and the fact they have been told it is OK.

Yes it's distorting the enclosure but I doubt that will go anywhere, obviously it's wrong.
As far as the SWA goes I'd be concerned about the incorrect connection to the banjo's, what code did you give that?

 

[Davisonp]

Yes it's distorting the enclosure but I doubt that will go anywhere, obviously it's wrong.

Thank you,
It appears I am over reacting to that.

With the banjos not being earthed, I had not noticed.
I have not done an EICR as the church will not pay for it, but I had seen what I believed was a danger and was trying to get them to make it safe.
If I were doing an EICR I would need to do a bit more research and check the other end, but I think it would be code C2. The cables are buried.

 

[davesparks]

Thank you,
It appears I am over reacting to that.

With the banjos not being earthed, I had not noticed.
I have not done an EICR as the church will not pay for it, but I had seen what I believed was a danger and was trying to get them to make it safe.
If I were doing an EICR I would need to do a bit more research and check the other end, but I think it would be code C2. The cables are buried.

I was referring to the incorrect connection to the banjo's which are earthed. The banjo is trapped between the gland and the plastic enclosure and the bolt passes through the plastic enclosure.
Plastic is soft and moves over time when compressed, the banjo should be trapped between two locknuts on the inside of the enclosure and the lug bolted to the banjo directly.

 

[Davisonp]

I was referring to the incorrect connection to the banjo's which are earthed. The banjo is trapped between the gland and the plastic enclosure and the bolt passes through the plastic enclosure.
Plastic is soft and moves over time when compressed, the banjo should be trapped between two locknuts on the inside of the enclosure and the lug bolted to the banjo directly.

The issue had not registered with me.
I have always earthed SWA as you describe, but I have also seen many examples of banjos connected through earthed metal Consumer Units using the enclosure to provide the earth, but, in this case, I missed the fact that plastic can compress and it has not been done properly.