Can you take 2 phases to a consumer unit?

[Gigsy]

Dual tariff board?

Not dual tariff

 

[davesparks]

T


There is nothing on the metal box which identifies it as being rated for anything, The switches are rated for 400v. But they are only subject to 230v each?
It is a normal domestic consumer unit?

That’s unusual, those contactum boards always used to have a label on the lid identifying the BS-EN standard they are built to, this standard will give the voltage and PSCC they are rated to. Maybe the sticker has fallen off?

 

[The Ghost]

Incoming neutral

Ah ok can see that now it makes sense.

 

[Gigsy]

That’s unusual, those contactum boards always used to have a label on the lid identifying the BS-EN standard they are built to, this standard will give the voltage and PSCC they are rated to. Maybe the sticker has fallen off?

I will take a look on the lid tomorrow, thank you.

 

[Gigsy]

That’s unusual, those contactum boards always used to have a label on the lid identifying the BS-EN standard they are built to, this standard will give the voltage and PSCC they are rated to. Maybe the sticker has fallen off?

I don't really understand this statement.

The metal box is just a metal box. The accessories inside the box ie. the switch, the RCD's and the MCB's are all marked with BS-EN numbers and breaking capacity numbers. Each accessory is only at a potential difference of 230v. I can do a PFC and PSCC test on the installation, but I know for a fact the tests will not exceed 6kA. Why do the accessories need to be rated at 25kA?

 

[Midwest]

I thought if you were going to use more than one phase, you used three to balance the load? So why would you use a domestic CU designed for a typical single phase domestic property, when you could use a properly designed three phase board, intended for that use?

 

[PEG]

I don't really understand this statement.

The metal box is just a metal box. The accessories inside the box ie. the switch, the RCD's and the MCB's are all marked with BS-EN numbers and breaking capacity numbers. Each accessory is only at a potential difference of 230v. I can do a PFC and PSCC test on the installation, but I know for a fact the tests will not exceed 6kA. Why do the accessories need to be rated at 25kA?

Not strictly true,as someone has had to assess,test,approve and certify that "box".

A test of this,is how many DB's with the equipment listed,have you seen,with a home made enclosure?

 

[Spoon]

I came across a consumer unit today,

I don't think he has wired this CU.

 

[Gigsy]

I thought if you were going to use more than one phase, you used three to balance the load? So why would you use a domestic CU designed for a typical single phase domestic property, when you could use a properly designed three phase board, intended for that use?

The 3rd phase (L1) goes to a consumer unit downstairs. I think they have balanced the load.

 

[Gigsy]

Not strictly true,as someone has had to assess,test,approve and certify that "box".

A test of this,is how many DB's with the equipment listed,have you seen,with a home made enclosure?

It is not a home made enclosure, It is made by contactum.
The box has a 400v sticker on it, so anybody who wishes to service it knows the potential voltage.

 

[Pete999]

Hi,

I am training to become and electrician, I have passed my C&G level 2 exams. I am working as an electrical improver.



I came across a consumer unit today, which has two main switches and two phases L2 and L3 supplying it.
I can see where you are coming from Gigsy, might seem a daft question but have you actually confirmed that the voltage between L2 and L3 is 4oo volts, I only ask because it seems an odd installation to me, probably barking up the wrong tree, but I thought I would ask just to be sure.



Does this board comply with regs?



Can you take 2 phases to a consumer unit?

View attachment 42245

 

[Wilko]

Hi Gigsy, been keeping busy I see !
These boards are intended by manufacturers to be used for single phase. For more than one phase a 3 phase board should be used, in my humble opinion. I would drop an email to manufacturer's tech dept for their view.

 

[Octopus]

I don't think he has wired this CU.

Are you SO sure?

He seems to be defending its use rather than learning the reasons its not really suitable.

I would have said that this "box" needs a 3P isolator, in it, or at the very least adjacent to it.

 

[telectrix]

not sure about regs. but I'd not be comfortable with it.(even if the wiring was not a rat's nest).

 

[Pete999]

Hi,

I am training to become and electrician, I have passed my C&G level 2 exams. I am working as an electrical improver.



I came across a consumer unit today, which has two main switches and two phases L2 and L3 supplying it.
I can see where you are coming from Gigsy, might seem a daft question but have you actually confirmed that the voltage between L2 and L3 is 4oo volts, I only ask because it seems an odd installation to me, probably barking up the wrong tree, but I thought I would ask just to be sure.



Does this board comply with regs?



Can you take 2 phases to a consumer unit?

View attachment 42245

 

[Spoon]

Are you SO sure?
He seems to be defending its use rather than learning the reasons its not really suitable.

No mate, I'm not sure. Just quoted what the OP stated in his first post. Lest ask...

I came across a consumer unit today

@Gigsy . Did you wire up this CU or do any changes to it?

 

[Pete999]

Don't know if my last post went anywhere Gigsy, may seem a daft question, and I'm only asking because I'm not sure what I'm looking at, but have you canfirmedthat there are 2 phases present, by testing the Voltage between L2 and L3

 

[Midwest]

The 3rd phase (L1) goes to a consumer unit downstairs. I think they have balanced the load.

Long time since I did any 3 phase stuff, but that doesn't appear to be a very good design. Either of those two DB's could be altered over time, and without in depth knowledge of the installation, one could be significantly altered in preference to the other. Unlikely to happen in a single dedicated 3P DB, IMO.

 

[Corbs]

Anyone else notice the screws arnt done up (top left and right) someone could lift it up and pull it off the wall

 

[westward10]

Anyone else notice the screws arnt done up (top left and right) someone could lift it up and pull it off the wall

Its a flexible board