Ask an Electrician anything...

[Teddy Lop]

richatnort said:

Teddy Lop said:

What do the instructions on the oven ask for?

Some require say 16a protection whereas the circuit might be 32.

It states hardwired,16amp, total connected load 3.6kW

If the oven states 16a then it should be observed to satisfy both regs and manufacturers safe use & warranty conditions. You could replace the circuit breaker or provide 16a protection at the end eg by way of MCB or fuse carrier in a small enclosure.

[PurpleFox]

Rental property

EICR in date, carried out 14 months ago

Plastic consumer unit, full retire less than 10 years ago. C3 on the eicr for plastic consumer unit.

Fitted with 2x clip on blanks on the front.

I would like to change these to blanks that fit on the DIN rail so they cannot easily be removed. (As I understand they should already be this type)

Strictly speaking, do I need a qualified electrician to remove cover, fit blanks, refit cover?

There is an isolator between elec meter and CU.

Thanks

[Teddy Lop]

PurpleFox said:

Rental property

EICR in date, carried out 14 months ago

Plastic consumer unit, full retire less than 10 years ago. C3 on the eicr for plastic consumer unit.

Fitted with 2x clip on blanks on the front.

I would like to change these to blanks that fit on the DIN rail so they cannot easily be removed. (As I understand they should already be this type)

Strictly speaking, do I need a qualified electrician to remove cover, fit blanks, refit cover?

There is an isolator between elec meter and CU.

Thanks

Nah, easy fix, do it yourself. For easy compliance a squirt of gloo to prevent removal would be enough, also if the busbar is shielded it's not a concern. Also relazic CU, you can buy metal cu covers, if it's all RCD and doesnt otherwise warrant replacement

[PurpleFox]

Teddy Lop said:

PurpleFox said:

Rental property

EICR in date, carried out 14 months ago

Plastic consumer unit, full retire less than 10 years ago. C3 on the eicr for plastic consumer unit.

Fitted with 2x clip on blanks on the front.

I would like to change these to blanks that fit on the DIN rail so they cannot easily be removed. (As I understand they should already be this type)

Strictly speaking, do I need a qualified electrician to remove cover, fit blanks, refit cover?

There is an isolator between elec meter and CU.

Thanks

Nah, easy fix, do it yourself. For easy compliance a squirt of gloo to prevent removal would be enough, also if the busbar is shielded it's not a concern. Also relazic CU, you can buy metal cu covers, if it's all RCD and doesnt otherwise warrant replacement

Thanks for that and I will take a look at the metal covers. Good tip re the glue.

[Bainbridge]

Consumer unit question. It's mounted high up on a solid wall, just inside the front door, and the unit wobbles a bit whenever I switch one of the circuits off or on.

Presumably the screws holding the unit to the wall just need nipping up. I can see 2 large slotted screw heads on the front of the unit, but I'm unsure if they're just holding on the front bit or the whole unit.

Can I go ahead and try to tighten the 2 screws that I can see by using an insulated screwdriver while the consumer unit is on? Or do I need to take something off the front to get at the mounting screws?

My mate said just run a bead of filler around it to stop it wobbling, but in my mind that's just a temporary measure because the screws will probably loosen further.

I'm aware that power is going up into the unit from outside even with it switched off, so don't want to do anything stupid.

I'm pretty handy with simple sparky DIY jobs such as spurring from a ring main etc, but anything to do with the consumer unit I leave well alone.

Thanks.

[Jakg]

Bainbridge said:

Consumer unit question. It's mounted high up on a solid wall, just inside the front door, and the unit wobbles a bit whenever I switch one of the circuits off or on.

Presumably the screws holding the unit to the wall just need nipping up. I can see 2 large slotted screw heads on the front of the unit, but I'm unsure if they're just holding on the front bit or the whole unit.

Can I go ahead and try to tighten the 2 screws that I can see by using an insulated screwdriver while the consumer unit is on? Or do I need to take something off the front to get at the mounting screws?

My mate said just run a bead of filler around it to stop it wobbling, but in my mind that's just a temporary measure because the screws will probably loosen further.

I'm aware that power is going up into the unit from outside even with it switched off, so don't want to do anything stupid.

I'm pretty handy with simple sparky DIY jobs such as spurring from a ring main etc, but anything to do with the consumer unit I leave well alone.

Thanks.

(not an electrician)

The screws are for the cover. That comes off to expose everything inside, inc the fixing screws. Definitely don't touch any of that while live.

[Bainbridge]

Jakg said:

(not an electrician)

The screws are for the cover. That comes off to expose everything inside, inc the fixing screws. Definitely don't touch any of that while live.

Thanks for that info. So the only option is for the main fuse to be pulled outside in the meter box?

It's a bummer because we recently had a smart meter fitted and had I known it was loose I could have tightened it up while the sparky had the power to the house off.

[Actual]

Bainbridge said:

Thanks for that info. So the only option is for the main fuse to be pulled outside in the meter box?

It's a bummer because we recently had a smart meter fitted and had I known it was loose I could have tightened it up while the sparky had the power to the house off.

Check if you have an isolator between the meter and consumer unit.

If not request one from your electricity supplier. I had this done previously by SSE and more recently BG and both did it for free and within a few weeks.

Note that like having a smart meter installed it is the electricity supplier that you pay your electricity bill to who does the isolator even though you could switch supplier the next day. Amazingly the DNO Distribution Network Operator does not install meters or isolators.

Also some smart meters have an isolator that the customer can use and of course all smart meters have the government sponsored isolator so that The Man can turn you off remotely but that is another story.

[essayer]

Little tip, both times I’ve had a smart meter installed I’ve asked for an isolator to be added and they’ve freely obliged. Even a three phase one.

[Actual]

essayer said:

Little tip, both times I’ve had a smart meter installed I’ve asked for an isolator to be added and they’ve freely obliged. Even a three phase one.

I needed a smart meter to use an EV tariff but had to go on the BG waiting list so I ordered an isolator and sweet talked the excellent installer to fit a smart meter at the same time.

[Bainbridge]

Thanks everyone for replying. Looks like I'll need to get an isolator fitted.

[Bainbridge]

Duplicate post.

[Regbuser]

I'd suggest you get an electrician in first - he can remove the cover, then assess if the wall fastenings can be re tightened safely. If they can, then no need for intrusive work that'll cost a lot more.

[Teddy Lop]

Bainbridge said:

Consumer unit question. It's mounted high up on a solid wall, just inside the front door, and the unit wobbles a bit whenever I switch one of the circuits off or on.

Presumably the screws holding the unit to the wall just need nipping up. I can see 2 large slotted screw heads on the front of the unit, but I'm unsure if they're just holding on the front bit or the whole unit.

Can I go ahead and try to tighten the 2 screws that I can see by using an insulated screwdriver while the consumer unit is on? Or do I need to take something off the front to get at the mounting screws?

My mate said just run a bead of filler around it to stop it wobbling, but in my mind that's just a temporary measure because the screws will probably loosen further.

I'm aware that power is going up into the unit from outside even with it switched off, so don't want to do anything stupid.

I'm pretty handy with simple sparky DIY jobs such as spurring from a ring main etc, but anything to do with the consumer unit I leave well alone.

Thanks.

Is it the whole unit fixings or just the cover fixings ? Lots of the buggers have pathetic covers .

If whole unit it'd be prudent to run a check across all the terminals inside to make sure nothings loosened.

Check+refix isn't a big job for a sparky if it's more than you wish to take a poke at.

[CSK423]

Looking to swap out an existing mira sport 9kw shower for a new 9kw or 10.5kw shower as part of an ensuite refurb.

I have done my own calcs on this but ultimately won't be carrying out the work, therefore I'd like a bit of comfort that the current install doesn't need altered and joe bloggs sparky doesn't get the variation book out on day one.

Current set up 9kw 6mm T+E fed by 40A RCD & 40A MCB 2m rise in a cupboard surface clipped, surface clipped in loft on joists 4m, 2m drop surface clipped in cupboard. (8m surface clipped)

My calcs say a like for like 9kw (39.1A load) straight swap is fine based on the above, Cable size based on the above install is 6mm with a max load of 48.4A. (original install was in place when we purchased the house) Therefore Mr Sparky should not be stating it needs increase to 10mm, do we agree ?

A 10.5kw (45.7A load) is where it gets grey. Cable size based on the above install is 6mm with a max load of 48.4A.
RCD/MCB will need uprated to 50A either way (a 45A may not trip but is too close)
The 6mm will be "fine" according to the above but will I be met with resistance from Mr Sparky and should it really be moved to a 10mm if we install a 10.5kw.

[ruggedscotty]

CSK423 said:

Looking to swap out an existing mira sport 9kw shower for a new 9kw or 10.5kw shower as part of an ensuite refurb.

I have done my own calcs on this but ultimately won't be carrying out the work, therefore I'd like a bit of comfort that the current install doesn't need altered and joe bloggs sparky doesn't get the variation book out on day one.

Current set up 9kw 6mm T+E fed by 40A RCD & 40A MCB 2m rise in a cupboard surface clipped, surface clipped in loft on joists 4m, 2m drop surface clipped in cupboard. (8m surface clipped)

My calcs say a like for like 9kw (39.1A load) straight swap is fine based on the above, Cable size based on the above install is 6mm with a max load of 48.4A. (original install was in place when we purchased the house) Therefore Mr Sparky should not be stating it needs increase to 10mm, do we agree ?

A 10.5kw (45.7A load) is where it gets grey. Cable size based on the above install is 6mm with a max load of 48.4A.
RCD/MCB will need uprated to 50A either way (a 45A may not trip but is too close)
The 6mm will be "fine" according to the above but will I be met with resistance from Mr Sparky and should it really be moved to a 10mm if we install a 10.5kw.

needs to be 10mm for > 8.5Kw so id be getting that upgraded, or lower the shower Kw.

[119]

ruggedscotty said:

CSK423 said:

Looking to swap out an existing mira sport 9kw shower for a new 9kw or 10.5kw shower as part of an ensuite refurb.

I have done my own calcs on this but ultimately won't be carrying out the work, therefore I'd like a bit of comfort that the current install doesn't need altered and joe bloggs sparky doesn't get the variation book out on day one.

Current set up 9kw 6mm T+E fed by 40A RCD & 40A MCB 2m rise in a cupboard surface clipped, surface clipped in loft on joists 4m, 2m drop surface clipped in cupboard. (8m surface clipped)

My calcs say a like for like 9kw (39.1A load) straight swap is fine based on the above, Cable size based on the above install is 6mm with a max load of 48.4A. (original install was in place when we purchased the house) Therefore Mr Sparky should not be stating it needs increase to 10mm, do we agree ?

A 10.5kw (45.7A load) is where it gets grey. Cable size based on the above install is 6mm with a max load of 48.4A.
RCD/MCB will need uprated to 50A either way (a 45A may not trip but is too close)
The 6mm will be "fine" according to the above but will I be met with resistance from Mr Sparky and should it really be moved to a 10mm if we install a 10.5kw.

needs to be 10mm for > 8.5Kw so id be getting that upgraded, or lower the shower Kw.

How come? The 6 seems to be within its rating?

[Teddy Lop]

CSK423 said:

Looking to swap out an existing mira sport 9kw shower for a new 9kw or 10.5kw shower as part of an ensuite refurb.

I have done my own calcs on this but ultimately won't be carrying out the work, therefore I'd like a bit of comfort that the current install doesn't need altered and joe bloggs sparky doesn't get the variation book out on day one.

Current set up 9kw 6mm T+E fed by 40A RCD & 40A MCB 2m rise in a cupboard surface clipped, surface clipped in loft on joists 4m, 2m drop surface clipped in cupboard. (8m surface clipped)

My calcs say a like for like 9kw (39.1A load) straight swap is fine based on the above, Cable size based on the above install is 6mm with a max load of 48.4A. (original install was in place when we purchased the house) Therefore Mr Sparky should not be stating it needs increase to 10mm, do we agree ?

A 10.5kw (45.7A load) is where it gets grey. Cable size based on the above install is 6mm with a max load of 48.4A.
RCD/MCB will need uprated to 50A either way (a 45A may not trip but is too close)
The 6mm will be "fine" according to the above but will I be met with resistance from Mr Sparky and should it really be moved to a 10mm if we install a 10.5kw.

Problem you have is a 230v/9kW shower might be rated at 39.1 amps at 230v but with the 240-245v it's more likey to see 41-42 amps is what you're looking at and tripping the breaker is sometimes an issue. many a plumbers downfall when they think theyre replacing like for like but the old shower was a 240v rated unit. Safe is stick to 8.5.

As for the 10.5 again real current draw could be 48-49 amps.

as for 6mm ratings, clipped direct might be sufficient but a good spark should ask himself if being covered with rockwall by some ignoranious - which changes the rating dramatically - is a foreseeable risk.

[BigBen]

Teddy Lop said:

Problem you have is a 230v/9kW shower might be rated at 39.1 amps at 230v but with the 240-245v it's more likey to see 41-42 amps is what you're looking at and tripping the breaker is sometimes an issue. many a plumbers downfall when they think theyre replacing like for like but the old shower was a 240v rated unit. Safe is stick to 8.5.

As for the 10.5 again real current draw could be 48-49 amps.

as for 6mm ratings, clipped direct might be sufficient but a good spark should ask himself if being covered with rockwall by some ignoranious - which changes the rating dramatically - is a foreseeable risk.

Won't the current decrease with higher Voltage so 37.5A at 240V?

[ruggedscotty]

BigBen said:

Teddy Lop said:

Problem you have is a 230v/9kW shower might be rated at 39.1 amps at 230v but with the 240-245v it's more likey to see 41-42 amps is what you're looking at and tripping the breaker is sometimes an issue. many a plumbers downfall when they think theyre replacing like for like but the old shower was a 240v rated unit. Safe is stick to 8.5.

As for the 10.5 again real current draw could be 48-49 amps.

as for 6mm ratings, clipped direct might be sufficient but a good spark should ask himself if being covered with rockwall by some ignoranious - which changes the rating dramatically - is a foreseeable risk.

Won't the current decrease with higher Voltage so 37.5A at 240V?

No current goes up - shower resistive load

amps is voltage divided by resistance... resistance stays the same. volts goes up then so does amps.