Replace Type 1MCB with Type C ?
 

Short Version.

Does anyone know if you can replace MEM type 1 M6 5A 51QEB circuit breaker
with a 6A type C. Will it fit the DIN rail and not foul the cover?

Long Version.

The consumer unit is manufactured by MEM and fitted with rail mounted type 1
breakers.

The lighting circuit has now become subject to nuisance tripping when a
light bulb blows. So I want to try replacing the breaker. However being an
old type its causing problems.

If this were a more modern unit with a 6A B breaker It would be easy to
first try changing it for a 6A C breaker (about £5)

However the type 1 are difficult to source and piece more expensive (£17.64
Newey and Eyre)

Thanks

BillP

Replace Type 1MCB with Type C ?
 

In article ,
"BillP" writes:
Short Version.

Does anyone know if you can replace MEM type 1 M6 5A 51QEB circuit breaker
with a 6A type C. Will it fit the DIN rail and not foul the cover?

They're obsolete (part of the old British Standard range), and
Type 1 breakers were too sensitive for most uses, and there is
no equivalent rating in the new EN range. Type B is (roughly)
Type 2, and Type C is (roughly) Type 3. I always use Type C
breakers for domestic lighting circuits, but even they can
trip when a lamp arcs across internally when it dies, depending
on cable lengths and how near you are to the supply. If you
really want to prevent this, a 5A BS1361 cartidge fuse carrier
would be a better prospect.

I can't comment on the ability to fit breakers into older CU's,
which is a separate matter. You would need to say what model
CU you have, and someone may then know. MEM have changed their
ranges over the years.

--
Andrew Gabriel

Replace Type 1MCB with Type C ?
 

"Andrew Gabriel" wrote in message
.. .
In article ,
"BillP" writes:
Short Version.

Does anyone know if you can replace MEM type 1 M6 5A 51QEB circuit
breaker
with a 6A type C. Will it fit the DIN rail and not foul the cover?

They're obsolete (part of the old British Standard range), and
Type 1 breakers were too sensitive for most uses, and there is
no equivalent rating in the new EN range. Type B is (roughly)
Type 2, and Type C is (roughly) Type 3. I always use Type C
breakers for domestic lighting circuits, but even they can
trip when a lamp arcs across internally when it dies, depending
on cable lengths and how near you are to the supply. If you
really want to prevent this, a 5A BS1361 cartidge fuse carrier
would be a better prospect.

I can't comment on the ability to fit breakers into older CU's,
which is a separate matter. You would need to say what model
CU you have, and someone may then know. MEM have changed their
ranges over the years.

--
Andrew Gabriel

I'll get hold of a 6A mcb and offer it up and see.

Thanks Andrew