New Comer requires a little advice on an unusual Mains Supply to the local pub.. HELP

[Red Spot]

Hi, I m very new to this so please go easy...

Got called out to the local pub yesterday to a supply fault, the Landlord has informed me that every now again (usually a Saturday night when they are busy) the pub will loose all power. The Supplier is called out and usually replace the Fuse next to the Transformer (the pub is out in the sticks, transformer probably about 50m away) The supply cable itself has burned out and been replaced twice already, Supplier says they are drawing too much current.

Clamp tested the incoming and found at the time it was drawing around 135Amps, now the fun bit! The incoming cable goes into the 100Amp main fuse, then has a split from the supply side into another 100Amp main fuse (2 x 100Amp main fuses being fed from one supply, single phase)

One Fuse then supplies one meter and the other a second Smart meter, both meters then go down to feed a Square D 3 pole 125Amp Main Switch, the third pole is linked to the first pole on the switch as its a three phase board (single phase supply)

All the circuits fed from this DB appear fine and are drawing as a total around 20Amps (lighting, sockets, Fire alarm etc) There is however a Three Pole Square D KQ 10C363 63Amp MCB feeding a five core 16mm SWA which supplies DB2 in the kitchen, this is drawing around 95AMps (split between the three poles, other two cores are Neutral and earth)

Checked the regs for a start and the 16mm multi-core SWA is rated (clipped direct which it is not) @ 77Amps (it is fed through the wall and i would guess through the ceiling void ground floor.

I m guessing the supply is only 100Amps as it keeps melting the supply cable to the pub and taking the supplies fuse by the transformer, so why on earth does it feed 2 x 100Amp main fuses, each would then require a current of over 100Amps to blow, therefore they are providing no protection to the building supply.

I v got some pictures but cant upload them yet, any advice on the above would be greatly appreciated.

Cheers

Chris

 

[DurhamSparky]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

you would need to ask the DNO why they fitted the arrangement like that!!

my first bit of advice would be to get the PUB/DNO to sort out this arrangement and possibly go for a 3phase install and uprate the cable... not a cheap option but one day the DNO will not reinstate supply until load reduction is achieved in the PUB...! or a increase in supply is arranged

 

[telectrix]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

pub kitchens are a nightmare. i have a customer ( pub) who has had to have a supply upgrade as he was drawing 130+ amps. when the kitchen was running. unfortunately his neares 3 phase supply is 3 miles away, so all he could upgrade to was a 160A single phase supply. in your situ. i would advise client to try and get a 3 phase supply in. bit of luck, the brewery might pay. either that, or convert some of the kitchen to gas.

 

[plugsandsparks]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

Wow thats a hell of a work around. I would double check the client side of the install for heat damage and generally how hot the DBs and cables are getting whilst pulling that load. Also find out what in the kitchen is pulling that amount of current, e.g. fryers, hot plates etc. In the short term you may be able to advise the client which appliances can be used together and which in sequence to stop the supply popping. If its in the sticks the DNO may have to upgrade quite a bit, hence this work around. Looks like its crying out for a TP supply mind.
Oh and get a bacon sandwich and shandy whilst there !! LOL

 

[Guest55]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

I find it highly unlikely that the DNO would replace the cable at their expense knowing that if the pub loading remains the same , the cable will get damaged again.
As mentioned by others 3 phase is probably needed and it wont be cheap.
Down to the landlord to sort out ultimately.

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

Cheers for the replies, as i said the pub is way out in the sticks, Supplier has quoted around £30k for 3Phase install (so i m told) I v never got involved with 3Phase first question is the current setup with the supply to the kitchen, the MCB is rated at 63Amps i assume that this is per pole, otherwise it would have been tripping with the 95Amps loading, also the cable is rated at 77Amps This is the total loading of the cable not per core, i know stupid question but its just bugging me that someone would actually install that.

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

This is the 125Amp Main Switch

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

This is the Main Fuse Split

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

This is the 63Amp supply to DB2

 

[Engineer54]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

What is the supplying transformer single phase or 3 phase?? Are there 3 lines on the overhead pole system??

If the transformer is 3 phase and only supplying the Pub and maybe one or two houses, then there shouldn't be too much of problem of suppling the Pub with a 3 phase supply. ...Certainly not 30k worth of trouble anyway...lol!!

 

[telectrix]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

now i.m confused. the supply to DB2 is 3 phase according to your pic.

 

[plugsandsparks]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

Strange use of colours for single phase, anyway. I would check the neutral, looks like its three into one.....LOL.
The cable is rated at 70 odd amps but it looks like you are spreading the load over the phase cores (well L1 anyway) and returning the lot over one neutral.

Is there anyway you can disappear on holiday for a while without actually touching anything.....Looks like they are going to keep hammering it until something really bad happens. If the DNO put in a slightly higher fuse next time, it could be the next weak link in the pub that goes.
I would check the connection tightness in the Dbs as well this will give you some idea of how hot its been getting.

 

[Des 56]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

now i.m confused. the supply to DB2 is 3 phase according to your pic.

What he appears to have is a 3 phase isolator supplied by 2 single supplies
)
One metered supply for 2 poles (there is a link across the poles) then the other metered supplies the third pole

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

There are two lines on the pole supplying the Transformer, it supplies the Pub, the 5 or six external bedrooms which the pub use as Bed and Breakfast and at least three houses that i can see.
There are only two mains supply cables into the pub, Phase and Neutral, there is no 3Phase supply, the spark that has done the orgional install has fitted what i would class as a three phase DB with 3Pole Main Switch and 2 x 3Pole MCB's (one of these which is doing nothing) I agree that 3Phase is a must or reduce the loading, but 30K investment for a small Freehold pub is pretty expensive.
Can anyone suggest reasons why the Supplier has fitted the two meters and split the incomer like they have? I will put up another pic. of the other meter.

Cheers

Chris

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

This is the Smart Meter

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

Strange use of colours for single phase, anyway. I would check the neutral, looks like its three into one.....LOL.
The cable is rated at 70 odd amps but it looks like you are spreading the load over the phase cores (well L1 anyway) and returning the lot over one neutral.

Is there anyway you can disappear on holiday for a while without actually touching anything.....Looks like they are going to keep hammering it until something really bad happens. If the DNO put in a slightly higher fuse next time, it could be the next weak link in the pub that goes.
I would check the connection tightness in the Dbs as well this will give you some idea of how hot its been getting.

Ye thats exactly what it is, the three poles from the 63Amp MCB all supply DB2 (again into a Three Pole MCB) all returning down one neutral (16mm) This cant be good practise?

Cheers

 

[Red Spot]

Re: New Comer requires a little advice on an unusual Mains Supply to the local pub..

While trying to sort out a resolution to the main loading issue i would look at doing the below in the mean time for safety reasons; (comments welcome please)

Ask the Supplier to come and remove the incoming split link or change the main fuses to 50Amp (if possible) then at least if the pub draws too much these should go before the fuse by the trasformer or worse the supply cable burns out again. At least then they stand a chance of getting the power back on quickly or only losing power to some of the pub as its split.

But i m not sure if i need to do anything with the supply cable to the kitchen, obviously i will need to let the client know what he can and cant use consecutively.

Any other points to look out for?

Cheers

Chris