Another pricing question

[Couleddie]

Been to have a look at a job today. First big one for me and a promise of more similar jobs to come.

3 bed 1970s terrace. Been totally gutted so nice and easy to work in. Bloke who owns it is a builder so no making good.

Complete rewire including bonding.

Lounge: 4 x sso, 1 x TV, 1 x pendant drop

Hall: 1 x sso, 2 way switching to 2 x pendant drop, 2way switching to landing

Kitchen: 10 x sso, FCU x 2 for washer, drier. 2 x lights. Cooker circuit. Radial for freezer. Light in store cupboard

Rear utility/Toilet: 2 x pendant drop, outside light, 1 x sso, Xpelair.

Bedroom 1: 3 x sso, 1 x pendant drop, Light in store cupboard

Bedroom 2: 2 x sso, 1 x pendant drop

Bedroom 3: 4 x sso, 1 x pendant drop

Landing: 1 x sso, 1 x pendant drop

Bathroom: 2 x SELV downlights, 9.5Kw shower

Loft: 2 x lights

Smoke alarms

I'm looking at the following as far as circuits go:

Up Ring 32

Down Ring 32

Kitchen Ring 32

Utility radial 20

Freezer radial 20

Cooker 32

Shower 40

Up lights 6

Down lights 6

All lights are going in existing locations as are most switches. Access to loft easy. Wooden floorboards up and down. Kitchen floor concrete.

May have missed something obvious so gentle reminders welcome.

Doing this myself - 2 weeks work. Worked out materials at under

 

[Dane]

For such a large job, would make ure life a lot easier to get some one in with you.

 

[Badger]

Been to have a look at a job today. First big one for me and a promise of more similar jobs to come. 3 bed 1970s terrace. Been totally gutted so nice and easy to work in. Bloke who owns it is a builder so no making good.

Complete rewire including bonding.

Lounge: 4 x sso, 1 x TV, 1 x pendant drop

Hall: 1 x sso, 2 way switching to 2 x pendant drop, 2way switching to landing

Kitchen: 10 x sso, FCU x 2 for washer, drier. 2 x lights. Cooker circuit. Radial for freezer. Light in store cupboard

Rear utility/Toilet: 2 x pendant drop, outside light, 1 x sso, Xpelair.

Bedroom 1: 3 x sso, 1 x pendant drop, Light in store cupboard

Bedroom 2: 2 x sso, 1 x pendant drop

Bedroom 3: 4 x sso, 1 x pendant drop

Landing: 1 x sso, 1 x pendant drop

Bathroom: 2 x SELV downlights, 9.5Kw shower

Loft: 2 x lights

Smoke alarms

I'm looking at the following as far as circuits go:

Up Ring 32

Down Ring 32

Kitchen Ring 32

Utility radial 20

Freezer radial 20

Cooker 32

Shower 40

Up lights 6

Down lights 6

All lights are going in existing locations as are most switches. Access to loft easy. Wooden floorboards up and down. Kitchen floor concrete.

May have missed something obvious so gentle reminders welcome.

Doing this myself - 2 weeks work. Worked out materials at under

 

[Bez]

I tend to put lights up on one RCD, lights down on another, and stair lights on their own RCBO, not required I know it's just a little added safety measure. You'll need a high integrity board anyway for the smokes, so why not make good use of it.

 

[Northern Electric]

The 9.5 KW shower will need to be wired in 10mm T&E via a 50A breaker

 

[binky]

The 9.5 KW shower will need to be wired in 10mm T&E via a 50A breaker

Why??? 6mm and 40A MCB works fine and has done for years, assuming clipped direct of course.

 

[Adrian]

tv points in bedrooms

bt points

roomstat /boiler point or immersion

bathroom fan

2k seems cheap you say no vat its not zero rated unless you are not vat reg

 

[Andy™]

tv points in bedroomsbt points

roomstat /boiler point or immersion

bathroom fan

2k seems cheap you say no vat its not zero rated unless you are not vat reg

VAT would still have been paid on materials

 

[Bez]

The 9.5 KW shower will need to be wired in 10mm T&E via a 50A breaker

Only if reference method C is used otherwise breaker is too big

 

[Northern Electric]

Why??? 6mm and 40A MCB works fine and has done for years, assuming clipped direct of course.

Belts and braces, just my opinion, obviously. I like to wire shower circuits in 10mm so it is always ready to take any shower that is available. Some showers are rated up to 11KW.

In tha case of a 9.5, voltage can vary in certain areas, 230V in some areas. 9500/230= 41.3A too high for a 40A mcb.

 

[Andy™]

Belts and braces, just my opinion, obviously. I like to wire shower circuits in 10mm so it is always ready to take any shower that is available. Some showers are rated up to 11KW. In tha case of a 9.5, voltage can vary in certain areas, 230V in some areas. 9500/230= 41.3A too high for a 40A mcb.

on paper its 230v.... in reality, its mostly still 240 or higher

 

[Bez]

9500/230= 41.3A too high for a 40A mcb.

Should carry it no probs for short duration of shower. Isn't there a given percentage over the rating that the device will carry? Maybe I've dreampt that one up.

 

[Andy™]

Should carry it no probs for short duration of shower. Isn't there a given percentage over the rating that the device will carry? Maybe I've dreampt that one up.

use the time/current graphs. for 41A on 40A MCB, i doubt it would ever trip

 

[Northern Electric]

It may well never trip, but I don't agree with installing an mcb which is rated less than the demand current. Ib In Iz.

 

[Bez]

[quote name='Andy

 

[Andy™]

It may well never trip, but I don't agree with installing an mcb which is rated less than the demand current. Ib In Iz.

neither do i, but for something like that, it unlikely to case a major problem. if it was in a commercial place where it was expect to be used many hours in a day, then it would be a bit different

 

[Bez]

It may well never trip, but I don't agree with installing an mcb which is rated less than the demand current. Ib In Iz.

Not ideal but protecting the cable a lot more, you could argue that we do it all the time in a kitchen ring if all appliances are on the go. You know what these women are like

 

[Northern Electric]

I do see what you are saying on the mcb front. It would be unlikely to trip unless you like an hour or 2 in the shower, it has been known!

On the cable front, I like to wire new shower circuits in 10mm to be future proof, I know it's a pain to terminate, but so is pulling a new circuit into an occupied house, might as well do it while it's empty.

 

[Andy™]

ideally, i would wire a new shower circuit in 10, but if changing the shower, we dont always have that luxury!

 

[Northern Electric]

I know Andy, but he said it was a total renovation with no making good, therefore chuck the 10mm in. He may well have decided to do that anyway, I was picking up on the MCB originally, but if many of you have installed 9.5KW showers via a 40A MCB with no problems, then fair enough. I usually fit 10.8 Mira sports these days, most people love them. I have one, damn good showers.