Replacing fuses with MCBs in Wylex unit

[flameport]

The MCBs also make it much easier and safer to isolate individual circuits than pulling the fuse. Which is pretty handy when doing DIY electrical work.

Only of use if the work is right next to the fusebox, so that you can still see the MCB.
If not, then relying on the switch only is dangerous, as it could be turned on again by anyone.

 

[Paul_C]

Although with the Wylex Standard Range plug-in breakers, you still have the option of quickly removing the breaker, just as with a fuse. And just as with a fuse, it doesn't somebody who is so inclined from replacing it with one from another position, or with a spare!

 

[mfarrow]

The argument goes that it's a new circuit?

Unfortunately I can't disagree with you there, although I would be amazed if this was ever picked up by BC officers or home buyers.

 

[Paul_C]

I would be amazed if this was ever picked up by BC officers or home buyers.

As they would have no idea of what was there before, how would they even know?

And seriously, anyone who is going to throw away £100-plus just to tell the local authority that he's going to replace BS3036 rewireable fuses with plug-in breakers in an old Wylex board must have far more money than common sense.

 

[Stoday]

The law says you don't have to notify if the work comprises:

“(a) replacing any fixed electrical equipment which does not include the provision of—
(i) any new fixed cabling; or
(ii) a consumer unit;”

As you are only proposing to replace the fuses (with MCBs) and are retaining the existing consumer unit, you don't need to notify.

 

[radweld]

The MCBs also make it much easier and safer to isolate individual circuits than pulling the fuse. Which is pretty handy when doing DIY electrical work.

I think it is safer to pull a fuse and put it in your pocket then you have more control. I can't imagine a diyer having locking dollys.

Although I can rely on the lock on my front door....

 

[empip]

Its changing the overcurrent protection for the circuit, and therefore notifiable.

Notso-sure about that... making the swap notifiable.

Building regs say...

(c) re-fixing or replacing enclosures of existing installation components, where the circuit protective measures are unaffected;

Note 'of' not 'or' - isn't the MCB a component ?

(d) providing mechanical protection to an existing fixed installation, where the circuit protective measures and current carrying capacity of conductors are unaffected by the increased thermal insulation.

Surely referring to - enclosures and not devices ??

Enclosure :- 'A part providing protection of equipment against certain external influences and in any direction providing basic protection.'

From The IET
...An enclosure is defined as a part providing protection of equipment against certain external influences and protection against contact.
This may be considered to include conduit, trunking, etc...

Basic Protection :- 'Protection against electric shock under fault free conditions. For low Voltage installations, systems and equipment, basic protection generally corresponds to protection against direct contact, that is "contact of persons or livestock with live parts".'

Other implications there may well be but I doubt swapping from rewireables to plug in MCB's is notifiable.

-0-

 

[Paul_C]

As you are only proposing to replace the fuses (with MCBs) and are retaining the existing consumer unit, you don't need to notify.

Good point. This is where the fact that revisions were applied to the rules so shortly after they were introduced gives rise to some confusion. The original wording for 1(a) in Schedule 2B was:

Work consisting of -

(a) replacing any socket-outlet, control switch or ceiling rose;

Clearly a fuse is none of those, so that exemption would not apply. The revised wording exempts a broader range of work though:

Work consisting of—

(a) replacing any fixed electrical equipment which does not include the provision of—

(i) any new fixed cabling; or
(ii) a consumer unit;

I know some people have argued that "replacing" in this context means (or was intended to mean) a like-for-like replacement, but as the regulations don't actually say that, I don't see that legally it can apply.

 

[ericmark]

Its changing the overcurrent protection for the circuit, and therefore notifiable.

Notso-sure about that... making the swap notifiable.

Building regs say...

(c) re-fixing or replacing enclosures of existing installation components, where the circuit protective measures are unaffected;

Note 'of' not 'or' - isn't the MCB a component ?

(d) providing mechanical protection to an existing fixed installation, where the circuit protective measures and current carrying capacity of conductors are unaffected by the increased thermal insulation.

Surely referring to - enclosures and not devices ??

Enclosure :- 'A part providing protection of equipment against certain external influences and in any direction providing basic protection.'

From The IET
...An enclosure is defined as a part providing protection of equipment against certain external influences and protection against contact.
This may be considered to include conduit, trunking, etc...

Basic Protection :- 'Protection against electric shock under fault free conditions. For low Voltage installations, systems and equipment, basic protection generally corresponds to protection against direct contact, that is "contact of persons or livestock with live parts".'

Other implications there may well be but I doubt swapping from rewireables to plug in MCB's is notifiable.

-0-

What if you planed to do it before 2004 and only just got around to it? Until a more realistic set of charges is introduced no one in their right mind is going to pay LABC £100+ to change a plug in unit. OK you do have to swap base so screw driver is required.
I have two fuse boxes of that type both feed from separate RCD's so I can isolate as required "Elsewhere" I have planed since 2000 to replace the three boxes with one box but not got around to it. However unless I use RCBO's there is no real advantage.

 

[Paul_C]

Until a more realistic set of charges is introduced no one in their right mind is going to pay LABC £100+ to change a plug in unit.

Or to do any one of dozens of other minor jobs.

 

[mfarrow]

I read approved document P, which states:

"Notifiable jobes include new circuits back to the consumer unit".

Isn't changing the characteristic of the protective device made it into a new circuit? Also, because of the way the graphs fall, the disconnection times may not meet the 5s rule for distribution circuits, therefore you cannot say the circuit protective measures are unaffected.

 

[Paul_C]

Isn't changing the characteristic of the protective device made it into a new circuit?

I'd say it's a modification to an existing circuit, not the provision of a new circuit.

Also, because of the way the graphs fall, the disconnection times may not meet the 5s rule for distribution circuits, therefore you cannot say the circuit protective measures are unaffected.

The clauses about "where circuit protective measures are unaffected" only apply in relation to specific jobs though. I can't see anything which would make swapping a fuse for an MCB fall into any of those categories.