Moving this away from a thread

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Then it would be against their instructions.
I didn't see the bit where they specified any particular make or for that matter anything other than double pole switched fused spur outlet with a 16A fuse.
Let's be fair and state that something of this ilk: https://www.cef.co.uk/catalogue/products/1538496-3x100a-3x125a-tp-n-switch-fuse-ip65 will satisfythe instructions. I haven't checked to see if 16A fuses are available to fit this so please not comments on that point.
 
What?

Why are you not just arguing that the 16 is a misprint?

To say that the MIs must be followed and then stating this may be achieved by doing something other than what they say is ludicrous.
 
The old Wilex fuse box, the fuses came with different diameter so you could not fit a 32A fuse in a 16A slot, but today although you can get fuse holders to fit in a consumer unit the fuse size tends to be up to 32A and there is nothing to stop one fitting a larger fuse even if as installed it had a 5A fuse in it.

I do see the whole idea of not allowing re-wireable fuses for use by ordinary person was to stop errors like 30 amp fuse wire on a 5 amp carrier, and any FCU which needs less than 13A it is very easy for wrong fuse to be fitted, every time I did PAT testing I would start with a pocket full of 3A fuses and finish with pocket full of 13A fuses.

Even the clock connection units now have BS1361 fuses in them, the fuse found in shaver adaptors seems to be rare now, and since 1A not 3A no real help, so the boiler must be fitted by a professional to comply with gas safe or Part P etc, but the user can swap the fuse for wrong size, so using a FCU one can't be sure correct size, but of course same goes for fuse inside a boiler.

To me the problem is, an electrician provides a electric supply, then the plumber fits the boiler, and gas safe guy does the commissioning, so the electrician can be fitting a FCU without ever seeing the instructions that come with the boiler, and I have looked for a type A RCD as part of a FCU and can't find the type even stated on the advert, I looked at the paperwork that came with my RCBO and again it says type B but that is tripping curve not the RCD type, so your looking for
Type-A.jpg
rather than
Type-AC.jpg
on the device, the 10 mA MK socket did have the
Type-A.jpg
sign on it, but needed two pair of glasses to read it, but I have never been asked to fit a type A RCD by anyone asking for a boiler supply, didn't even know Worcester Bosch asked for it until @stem pointed it out.

As to even checking the fuse size in a FCU when doing an EICR I would have passed it with any BS1361 fuse, I have not considered it as part of my remit to read the boilers installation instructions and astatine what protection it required. Only if it had a sticker saying 3A would I consider 13A as wrong. I have bought boxes of plugs and FCU's with 3A fuses fitted, but would not think I could get one in B&Q.

As I have said my boiler does have a 3A fuse, not a clue if boiler asks for 3A, but Nest does it says 3A resistive and 1A inductive 100 - 240 volt 50/60 Hz even though the model sold in USA is completely different. But the Nest Gen 3 is Europe version not UK only, however there is very little chance that a boiler, motorised valve or pump will without some one messing with it, draw more than 3A but less than 16A. The Nest Gen 3 I have would need a 1A fuse it seems, as the motorised valve is inductive, and the fan/oil pump and ignition module in boiler also inductive, but the fuse limits the fault current, not running current, so if the motorised valve uses 6 watt, contacts rated 2.2A, at 26 mA load it is hardly going to blow even a 1A fuse before it is damaged, and how you can get a 2.2A fuse don't know. The boiler is 155W (674 mA) so total load is around 750 mA so yes should all run on a 1A fuse.

But point is the electrician provides the FCU for the guy fitting boiler, and rarely even sees the spec for boiler, he may never even see what boiler is being fitted, so in the main it is down to the guy fitting boiler to check fuse size and RCD type. Electrician is rarely on site at same time, even if he arrives after to fit the FCU he is rarely given the boiler instructions, he assumes 3A, but he often does not know.
 
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What?

Why are you not just arguing that the 16 is a misprint?

To say that the MIs must be followed and then stating this may be achieved by doing something other than what they say is ludicrous.
I assume this is aimed at me.
I am not suggesting anything contradictory to the MI, I have simply come up with a fused switch to satisfy the MI, albeit one that is much larger than required [first hit on Google for 'fused switch'].
I assume the 16A in the instructions is an error but without seeing the rest of the MI I'm not in a position to know.
AFAIC a 16A MCB in the CU with a 20A DP switch at the equipment would be adequate to satisfy the essence of the instructions, but as mentioned by myself previously that would create a 'get out' when something goes wrong.

I had a new boiler fitted which didn't work. An engineer was sent out with a form to complete. Not exact words quoted.
1) Check bonding at meter.
2) Check fuse size.
3) Appliance details.
4) Installation manual completed by installer details.
5) Service history details.
6) Bypass valve fitted
7)...

And yes he went through the order on the form, actually getting to the boiler itself was halfway down the page [other than 3) appliance details] and he didn't resolve the issue so the following day a similar form was completed by a second engineer.
 
But point is the electrician provides the FCU for the guy fitting boiler, and rarely even sees the spec for boiler, he may never even see what boiler is being fitted, so in the main it is down to the guy fitting boiler to check fuse size and RCD type. Electrician is rarely on site at same time, even if he arrives after to fit the FCU he is rarely given the boiler instructions, he assumes 3A, but he often does not know.
I agree wholeheartedly with your post, Half the time he doesn't even know it's for a boiler and probably wouldn't 3A in it even if he did know.
 
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As a result of this thread, I looked at my consumer unit, all the RCBO's at type AC
Type-AC.jpg
so looked at other RCD's I have knocking around, only one with a type A is a 10 mA MK RCD socket hard to read but is a type A
Type-A.jpg
the only RCBO I can get for the CU which is type A is 6 amp, no others are made to fit it, so at first glance it would seem fitting the RCD socket would result in having the right type of RCD.

But if it asks for type A will fitting a RCD socket really help? The socket may trip as it should do, but would having a item needing a type A on the circuit stop the RCBO type AC from working when the fault was not due to item needing a type A?

If I could buy a RCBO type A RCD and type B tripping curve then swapping would not be a problem, they were only around £10 each so not a big issue, but how many electricians drive around with a selection of RCBO's on the van just in case? If I had a new boiler and it needed a type A RCD then likely the guy would have to drive 20 miles to Welshpool and back and if not in stock in Welshpool an extra 15 miles to Newtown, I wanted a load capacitor for LED lights to stop them flashing, thought it would be stocked everywhere, only CEF had them.

Since the type of the RCBO is not shown on the web adverts, in the main some one has to open the packet and check what type, not tried phoning a supplier and asking for a type A RCBO but I will guess if I want one it will need ordering, OK if for me and fitted by me, but for a customer it means two visits instead of one. And the MK metal clad RCD 10 mA socket is not cheap, think around £70 and as said not sure if OK to have a type A fed from a type AC?
 
The photograph clearly shows a standard UK FCU and asks for a 16a fuse in it. The switch fuse Sunray suggested is not the same and would not be following MI. As to 16a being a misprint I don’t think so as it is a 16a oven.
 
The photograph clearly shows a standard UK FCU and asks for a 16a fuse in it. The switch fuse Sunray suggested is not the same and would not be following MI.
I agree. Sunray cannot have it both ways.

As to 16a being a misprint I don’t think so as it is a 16a oven.
If it is not a misprint then it must be a mistake.

If it truly is a 16A oven then it should not be connected to a 13A FCU.
If it could be fitted to a 13A FCU with a 13A fuse then it should come with a plug.


Is there an online copy of the instructions?
 
If it truly is a 16A oven then it should not be connected to a 13A FCU.
What is a "16A oven"?

If you mean an oven which has a maximum load of 16A then, as I don't need to tell you, a cooking appliance with that maximum current represents only an 11.8A load after diversity.

I don't really see any conceptual difference between a cooking appliance with a maximum, load of, say, 50A connected to a 32A MCB (which I presume you would think was fine) and one with a maximum load of 16A being connected to a 13A fuse, do you?

Kind Regards, John
 
What is a "16A oven"?

If you mean an oven which has a maximum load of 16A then, as I don't need to tell you, a cooking appliance with that maximum current represents only an 11.8A load after diversity.

I don't really see any conceptual difference between a cooking appliance with a maximum, load of, say, 50A connected to a 32A MCB (which I presume you would think was fine) and one with a maximum load of 16A being connected to a 13A fuse, do you?

Kind Regards, John
Ah that depends entirely on what the appliance is.
For a Cooker with a selection of heating elements [10 is not uncommon these days] it is very unlikely that all elements will be in use at one time. However an appliance with a single load of 16A, incuding fan & light which will always represent a single load, then surely, that load must be fully catered for regardless of whether it's a cooking appliance or not. I'd consider it bad practice to place a known 16A load on a 13A fuse.
 
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I agree. Sunray cannot have it both ways.


If it is not a misprint then it must be a mistake
I'm not trying to have it both ways. The MI asks for a 16A FCU, all I've done is googled for 'fused switch' and the very first hit happened to be the one I quoted and it happened to be rated in excess of 16A and therefore would not create a safety issue.
I don't see why it has to be a misprint or a mistake.
If it truly is a 16A oven then it should not be connected to a 13A FCU.
If it could be fitted to a 13A FCU with a 13A fuse then it should come with a plug.
Agreed in principle.
 
I seem to remember my oven can draw something like 20A, you can select back fan, sides, top, there is a 12 position switch, and the oven very like the old solid fuel oven with dampers, can be set to heat in different ways according to food being cooked, however it seems some one has re-written Mrs Beeton's as it no longer tells how to set dampers, and it has gas mark settings, and gas had not been rolled out at time she wrote the book.

But one reason for stand alone cooker, the oven warms up faster.

As to fuse size required, depends on insulation and oven size, with a range cooker it uses power for an extended time, with my cooker 5 minutes and the thermostat is switching off/on, I have seen many times a shower on a MCB technically too small, and I would guess a 16 amp oven would run on a 13A fuse, however I would not say that is the way it should be done, diversity is size of largest device then percentage of others, so if one set of heating elements is 3.5 kW then in theory should not be on 13A fuse.

But the manufacturer of my cooker says full load 65A but still says supply from 32A MCB/RCBO.
 

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