Can I straight swap 45A for 32A in consumer unit?

[Kyrie]

Please can someone help?

I had a new double oven/ceramic hob freestanding cooker delivered this morning. Belling FSE60DO.

Paid in advance for this to be installed on delivery.

Man came, looked at the consumer unit and said "oh can't install it, needs a 32A and you have a 45A. Goodbye.

Can I straight swap the 45A trip thing in the consumer unit for a 32A one, or is there more to consider?

He didn't open the little box behind where the old (gas) cooker was, so how did he know that the wires leading to the cooker switch were the right size?

Do I get the 10mm cable to go from cooker to wall, or do I have to use whatever size has been used to wire the box where the cooker goes to the cooker switch?

The cooker switch also has a normal plug (so I can plug my kettle in for example), do i have to consider this when it comes to the size of the fuse thing in the CU?

I moved in 6 months ago and recently divorced... Money is precious and I really can't afford an electrician!

Thanks anyone

 

[AndyPRK]

Do you really have that the correct way round ?

If you do yes you could. You could also just not bother. (but against manufactures instructions I assume).

What you can't do is remove a 32A and fit a 45A without being sure the cable/switches are upto the job.

 

[Taylortwocities]

Hiya

The first thing is for you to realise what the trip thing in the fuse box is for. It is there to protect the cable that runs from the fusebox to the cooker/oven.

So, we need to know what size the cable is. That is not the dimension of the cable, it is the CROSS SECTIONAL AREA of the copper conductor in the cable. You'll need a digital micrometer and some knowledge of mathematics to work this one out.

It is possible to guess at it if you give us the width and depth of the cable in mm.

So, that's the first thing.
Next thing is changing the trip thingy. This is not a trivial thing to do if you have a modern type consumer unit. Can you take a photo and post it on here?

Hmm, why do I keep getting the whiff of a troll.....

 

[EFLImpudence]

Not many lorry drivers do electrical work.

If it was delivered by belling then they should have sent someone competant.
They obviously owe you a refund which you can use to employ an electrician.

 

[Kyrie]

Hiya!

I can tell you that the diameter of the green/red/black wires that run into/out of the cooker switch are approx 150mm diameter.. If that is any use at all... I can't get to the grey cable to measure it (sorry) they are quite chunky wires (compared to a normal 13A plug)


I can't get a photo onto the PC (lost cable and I don't have bluetooth) but I can tell you it is approx 10 years since the house was re-wired (allegedly) and that the CU is MK Sentry and that the number on the cooker trip thingy is LN5945 (45A) and I can also tell you that there are 7 trip thingys and looks like another one could be added, but it is blanked off. They don't have individual trip buttons on them incase that helps

Many many thank yous (I need an electrician don't I?!)

 

[Kyrie]

Oops... I mean 15mm Doh

 

[Kyrie]

Hmmmm... I guess not many lorry drivers are electricians!

BUT the sales guy at Currys was a builder !!

 

[echoes]

"The appliance must be installed by a
competent electrician using a double
pole control unit of 32 ampere minimum
capacity with 3mm minimum contact
separation at all poles."

EDIT:
"Electrical supply/load
220 - 240V ~ 50Hz
8960 - 10665W"

If the cable was undersized for 45A then fair enough, but there is nothing wrong with connecting that cooker to a 45A circuit.

 

[chivers67]

I just looked at the Belling site to see the spec on the cooker and it appears it requires 32amps, so Taylortwocities advice in this instance is spot on and the lorry drive/installer bloke is infact an idle idiot or was in some kind of rush to get home early so blew the install out.

 

[ban-all-sheds]

The lorry drive/installer bloke is probably only trained to check for a 32A supply and to know which is L, N & E.

He won't actually understand what he does, and the fault there is not his, it is 110% Curry's.

If you can manoeuvre the cooker and use wirestrippers and a screwdriver you can connect it yourself.

 

[Kyrie]

Thanks for all your help.

Can I just ask one more thing: When I go to the shop for the cable to connect the cooker to the wall, does it matter if I get 6mm or 10mm?

thanks again... You've been more helpful than than the Currys installer!

 

[john2509]

Hi Kyrie

First of all, I'd say that it is highy likley your cooker switch is wired in 6mm t&e cable as in all my years I've never known a cooker to be wired in anything above 6mm. If this is the case then then MCB (tripy thingy) in your consumer unit needs replacing with a 32 amp one because 6mm cable is not rated at 45 amps and if left has the potential to set on fire. If by some chance it is wired in 10mm t&e then putting a 32amp mcb in place will not affect it in any way and they cost under a fiver for your peace of mind.
To change the mcb, just simply switch the mains off, via the big red switch on the consumer unit and undo the screws from the bottom of all the mcb's and the terminal on the main switch which has the busbar connected to it, this should result in the copper bar falling out. Underneath the mcb is a small black clip, just put a screwdriver into the slot and put down slightly and the mcb should then lift off the rail. Just do the whole process in reverse fitting the new 32 amp mcb.
Once this is done, buy yourself a short piece of 6mm t&e to go from your cooker switch or connection box behind the cooker and connect to the back of the cooker.

Hope this helps

John

 

[ricicle]

If this is the case then then MCB (tripy thingy) in your consumer unit needs replacing with a 32 amp one because 6mm cable is not rated at 45 amps and if left has the potential to set on fire.

6mm² is rated at 47A clipped direct.

 

[echoes]

If your cooker circuit is 6mm², clipped direct, less than 18m of cable, TN-S earth (29m for TN-C-S) and Ze is within the nominal limits, then a 45A type B MCB should be adequate.

 

[ajrobb]

From OSG Appendix 8.4: "A 30 or 32 A circuit is usually appropriate for household or similar cookers of rating up to 15 kW."

Circuits up to 32A have to be protected* with a 30mA RCD but larger circuits can have different RCD ratings, so there might be another change. Work on a CU is notifiable to Local Authority Building Control under Part P of Building Regulations so is better done by an electrician who is a member of a competent persons scheme.

It is rare for an existing circuit to have concentric earth protection etc. and not need RCD protection.