garage consumer unit

[Pump Tech]

Dear All,
we are due to install a new pump station and found the property has many DB's, the one we are looking at is wired direct to DNO supply via a RCd then Henly block. (DB2)

The garage has a supply out of the property(lets say garage 1) which is linked through the sockets. i want to take a line from this supply (garage 1) and split it to take the new pump station. so i will need to install a mini CU. i believe this will be under Part P, but not so sure as this would have already been checked.

I would like to know what other would classify it as? also would i take the ZE from DB2? and if the RCD trips on high, should i take a reading via Zs

 

[telectrix]

sounds like a right bodge up already there.more info required to advise on a way forward.

 

[Pete999]

You need to get an electrician involved Mate

 

[HandySparks]

Dear All,
we are due to install a new pump station and found the property has many DB's, the one we are looking at is wired direct to DNO supply via a RCd then Henly block. (DB2)

The garage has a supply out of the property(lets say garage 1) which is linked through the sockets. i want to take a line from this supply (garage 1) and split it to take the new pump station. so i will need to install a mini CU. i believe this will be under Part P, but not so sure as this would have already been checked.

I would like to know what other would classify it as? also would i take the ZE from DB2? and if the RCD trips on high, should i take a reading via Zs

If this is a residential property, all new electrical work has to comply with Part P of the building regs and, in practice, with BS 7671. If you are going to install a new final circuit for a pump, then the work will require notification to the local authority in accordance with Part P.

Sounds like you need to employ the services of a competent electrician.

 

[Pump Tech]

sounds like a right bodge up already there.more info required to advise on a way forward.

its a little tricky, but the DB2 is not running through the main consumer unit. it is protected by a 100a switch. The consumer unit DB2 runs an annex and the garden lights run off the main ring circuit. We just want to take power from this circuit to the small pump. I was wondering if, such this is under the Part P or as already there would have been checked and signed off under Part P as it already exits the building. We need to split the lights from the pump using a small garage unit.

My other question was, as DB2 is directly wired to the henly block and the tails from this goes through the Main RCD, and not via any other CU, where will the Ze come from? Will it need to be taken from DB2 as this is linked direct to the DNO supply.

It is an usual one, I do the Part P, but It's normally straight forward for us. We don't do major electrics like you Pro's do, and definitely not Changing CU's or rewires etc. We purely do just the Radial Circuits when needed.

I appreciate any help on this one.

 

[Deleted member 9648]

The only place Ze can be measured is at the origin of the installation.

 

[LeeH]

No point in taking any measurements when you cannot decipher them

Get a spark in.

 

[Pump Tech]

The only place Ze can be measured is at the origin of the installation.

That what I thought, but if a Ze was to be taken from a Cu, as normal, and the Db2 is wired direct to the Dno supply, then can this be deemed as the origin. To me I believe this would be, as the Main Cu for the rest of the house also runs off the Henley block and neither supply each other.

 

[Wilko]

Hi Pump Tech - to simplify, all electrical work anywhere on a block of land that's got a house on it must comply with Part P as well as BS7671.

 

[Des 56]

Ze is earth loop impedance external to installation
Its therefore only possible to be obtained at the origin,no where else,its where the external earth path originates and thats at the incomer

 

[123]

Hi Pump Tech - to simplify, all electrical work anywhere on a block of land that's got a house on it must comply with Part P as well as BS7671.

Only if that house and block of land are in England and/or Wales

 

[Octopus]

"I do the Part P"

Are you sure?

 

[Wilko]

Only if that house and block of land are in England and/or Wales

Oops - my mistake !

 

[HandySparks]

its a little tricky...

No, it's not.

...the DB2 is not running through the main consumer unit. it is protected by a 100a switch.

A switch provides no protection. Just a means of isolation.

...the garden lights run off the main ring circuit. We just want to take power from this circuit to the small pump. I was wondering if, such this is under the Part P or as already there would have been checked and signed off under Part P as it already exits the building. We need to split the lights from the pump using a small garage unit.

What's the rating of the pump?

How is the lighting circuit currently protected?

Why are you proposing to use a 'garage unit' fed from the ring circuit?

 

[Pete999]

Get a Sparky involved please