ChrisW
|
posted on 29/3/17 at 01:16 PM |
|
|
Wiring (mains type)
I know we have a few electricians here so hopefully someone will give some advice.
I need to fit a meter to a fuse board. The meter needs a low current mains supply of it's own.
To save wasting a 'way' on the board (and so that the tenant can't easily switch the meter off) I was intending to install a fuse
holder inside the board to feed the meter.
The fuse will be 2A (or whatever the smallest is that I can get) but will be fed from a 63A incomer.
Does the wire feeding the fuse need to be rated at the full 63A or will >2A suffice?
My thinking is that if >2A is pulled the fuse will go and protect both the wire feeding it and the downstream wire to the meter. On the other hand
there could be a situation where the wire feeding the fuse could be shorted and in that case it needs to pass enough current to blow the upstream
fuse.
Any advice please?
Chris
[Edited on 29/3/2017 by ChrisW]
My gaff my rules
|
|
|
MikeR
|
posted on 29/3/17 at 04:17 PM |
|
|
Not an electrician but the fuse needs to be smaller than the cable can cope with - so if using a 2amp fuse use a 5amp cable therefore the fuse will
always blow before the cable fails.
|
|
daviep
|
posted on 29/3/17 at 04:45 PM |
|
|
Sorry not an electrician either but logic says that upstream of the fuse should be rated higher than the 63A incomer fuse in case as you say there is
a short in the cable before the 2A fuse.
Cheers
Davie
“A truly great library contains something in it to offend everyone.”
|
|
coozer
|
posted on 29/3/17 at 06:49 PM |
|
|
I would run 10mm cooker cable from the 63 to the 2....
1972 V8 Jago
1980 Z750
|
|
ChrisW
|
posted on 31/3/17 at 03:17 PM |
|
|
Thanks guys. I had concluded that the feed to the fuse should be >63A but was hoping someone would tell me otherwise.
Chris
My gaff my rules
|
|