ONE BUILDING 2 SUPPLIES

[sparkytim]

Hi PIR on Dental Practice 2 Houses knocked thru at various levels has original supply in each building and some circuits appears to cross over from one to the other.

Any specific reg that would code this? Or will 537.1.6 cover it?

Comments welcome

Thanks

 

[ianmacd]

There is one about shared Earths that may need the 2 MET's linked. Have no BRB in front of me to check atm.

 

[ianmacd]

There is one about shared Earths that may need the 2 MET's linked. Have no BRB in front of me to check atm.

Kinda right. 542.1.8. Could be satisfied with linking the 2 METs with a suitably sized Earthing Connector.

 

[binky]

What about 415V volt shock risk. Items on different supplies that are within touching distance should be labelled as potential 415 risk - what code that would be I'm not sure, but think I would go with code 2, although better solution might be to label which CU/circuit the accessory is being supplied from with dyno tape or some other permanent marking method.

 

[ianmacd]

What about 415V volt shock risk. Items on different supplies that are within touching distance should be labelled as potential 415 risk - what code that would be I'm not sure, but think I would go with code 2, although better solution might be to label which CU/circuit the accessory is being supplied from with dyno tape or some other permanent marking method.

Assuming they are not on the same phase.

 

[binky]

I think that's a fair assumption as I understand DNOs like to supply each house in a street on a different phase (in sequence of 3 obviously) to help balance their loads. But I'm sure there are exceptions to this.

 

[ianmacd]

I thought they preferred to put semi's on the same phase for the very reason in this thread. Also sure DNO were advised of the comunal installation (I hope so anyway) so would have objected if they were on different phases (or at least flagged it).

 

[Apache]

How could you test to see if they were on the same phase? Live to live of the two supplies (I mean across a meter)?

 

[sparkytim]

400 Volts L TO L if diff PHASE 0 Volts if same.

Thanks all, One supply is 3 phase and the other single, so already Phase location issue.

Only went to look at job to give quote for a PIR, but all such a mess don't know if I really want to get it.

A Company from Manchester IS down here in Lowestoft doing refurb of parts have flagged up problems, looks abit of a nightmare to be honest, how do you quote for a PIR on something like this?

8 DBs NO schedules, no circuit identification, looks like a Builders bodge going back for years.

 

[ianmacd]

T&M

 

[Sidewinder]

Do it on an hourly!

 

[Adrian]

if you are worried about what price to give for a pir how are you going to price the remedials. as a guild I would go

 

[sparkytim]

Thanks all

Have stuck in price for circuit identification and a Limited visual hoping not to get it and guess what?

Have orded a Martindale Fuse finder kit Elite 650 any one tried them out?

 

[ianmacd]

Thanks allHave stuck in price for circuit identification and a Limited visual hoping not to get it and guess what?

Have orded a Martindale Fuse finder kit Elite 650 any one tried them out?

Yep thats the one I have too. Seems to work better with mcb's than with rewireables. Useful piece of kit.

 

[sparkytim]

Had a busy weekend but got done, just a shame the Fuse finder didn't find ME.

Megger Marks crew let me down there, but managed with 2 of us + Radios, me pulling Fuses and me8 running around with Martidale and Loop tester.

Two PIRs (one for each supply) 10 DB Schedules, so spent a good while on the Report.

I spoke with DNO this morning and they have no issue with 2 supplies as it is existing arrangement.

I have recommended 16mm Bonding between the Two METs and changing one supply over to the Same Phase as the other (Only 1 Phase used of 3 Phase available on one side of Building) to remove 415 Volt hazard

Deliverd Paperwork to site this morning and fitted DB Schedules along with

Warning notices ( THIS BUILDING HAS 2 SUPPLIES.......)

I have put in quote for remedials and upgrade and await result of meeting with client tomorrow.