FCU

[steve_the_joiner]

Hi,

Our resident sparky doesn't distinguish between load and supply terminals when he wires in fcu's.

My understanding is that the supply terminals will be rated 2 at least 32A 2 accomodate the ring whereas the load terminals only have 2 be manufactured to comply with a load of around 13A

OK in a spur situation if he uses load for supply and vice versa

If it's wired into the ring like that, I'm a bit concerned the load terminals can't cope with full ring current.

Answers appreciated

Steve

 

[andy]

Hi,

Our resident sparky doesn't distinguish between load and supply terminals when he wires in fcu's.

My understanding is that the supply terminals will be rated 2 at least 32A 2 accomodate the ring whereas the load terminals only have 2 be manufactured to comply with a load of around 13A

OK in a spur situation if he uses load for supply and vice versa

If it's wired into the ring like that, I'm a bit concerned the load terminals can't cope with full ring current.

Answers appreciated

Steve

max current in will be the same as out. which is 13A. only time it really matters is when there is a neon (wrong way round the neon will be permantly lit)

 

[steve_the_joiner]

Thanks Andy.

However, I think my post might be a bit ambiguous. He has the fcu connected as an integral part of the ring, same as a socket would be wired.

He hasn't taken a feed from the ring to supply it as a spur.

I'd have thought that the terminals used for the ring connection should be rated to full ring current and not just load current as essentially these are acting as a simple connection terminal for both sides of the ring.

I apologise if my wording was misleading, or if I've still got the wrong end of the stick

Steve

 

[Adam_151]

I understand what you are saying, and while I would consider it bad practice to do what your sparky is doing, in reality, I don't really think there is any difference in the construction of the terminals. Can't see why he just doesn't connect it up the right way, and if he is doing it 'slap dash' I'd wonder what other things he is not taking proper care with, is he makeing sure to get phase and neutral the right way around?

EDIT: and if in future someone spurs off the 'load' side, they might be unwittingly creating an unfused spur, and if someone tries to do said task by cutting the power by withdrawing the fuse and doesn't test that the terminals they are connecting into are dead...

Just far easier to to it properly...

 

[BSBS]

It is bad practice to wire the FCU as you say he has this is beacuase the fuse will always be live.. for example when done correctly the current flow should go as follows..

Input Terminals - Switch - Fuse - Load

When wired correctly when you turn the FCU off at the switch you cut the voltage to the fuse and can safley remove the fuse. However if you wire them incorrectly (backwards)

Load terminals - Fuse - Switch - Input terminals

Then when you turn the switch off you are not actually switching if the voltage to the Fuse and on some older FCU's it is possible to acces the live terminals of the fuse holder when the carrier is removed which is not a good situation to be in.

Hope that makes sense

 

[steve_the_joiner]

Thanks lads for the replies.

Regarding the terminals, the current ones we use are same rating for supply/load, however I've seen a few older ones that have smaller terminals for the load that don't look up to carrying a full ring current.

At the end of the day, I'm a joiner so it's not really my problem, however I do have to connect appliances such as cooker hoods, fires etc into his fcu's after I've completed my own work.

Each time I've come across this I've rewired the fcu just so I'm happy it's as it should be.

I don't know why he wires them like this, and as you say it does make you wonder if he's got any other shoddy practises.

Steve