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Allan White

Hi all... I'm new here and already looking for help with an odd request :)

I'm looking for a lockable double pole switched fused spur suitable for domestic installation... does anyone here know if such a thing is available?

Even an hour with Mr Google doesn't turn anything up and I really don't want to fit an industrial red/yellow double pole 'rotary' isolator between the spur and a new CHP boiler (how many woman would have that in a kitchen???).

BTW the reason I'm asking is that I work in the micro CHP field and the upcoming G83 requirements will mean all micro CHP boilers will require a lockable double pole isolator to be fitted. Note this is subtly different from the current regs which require a securable dp isolator (eg a domestic switched fused spur).

Thanks in advance y'all

Allan
 
if it specifies a lockable isolator then a fused spur wont be required, a normal isolator will do and they are readily available.

OP states he wants a DP fuse spur, the circuit design may be such that it needs fusing down, he looking for a kitchen asthetically friendly one at that so it looks like a standard FSU, if you know of any readily available that meets the OP's requirements then pls forward a link as i have only come across surface mount padlockable metal clad versions.
 
If there is going to be a demand for them, manufacturers will start making them.
They may already have them under way.

Have you tried contacting Mk and the like directly?
 
If you can't find anything use a normal dp s/fcu and cut the arse out a lockable key box and mount that over it.

Edit: something like this.
 
Incidentally for those following this thread that might not be aware - conecting a micro chp to a ring circuit requires the ring fusing to be downrated to 25A...

If your connecting to a ring circuit your FSU would be your fusing down as would a plug top if directly plugged in, not all brands of DB have a 25amp fuse range so cant quite understand where this is coming from, you cant have a product demanding an alteration to existing circuit design (the ring in this case) that is fully compliant and fused at 32amp, if this is the case the manufacturers should be stating that its not to be connected to the ring main. Any contractor following and maybe doing work on or testing the ring will quite rightly state the 25amp although safe would benefit more with a 32amp fusing not aware that 1 product attached has created this situe.
 
Hang on this has gone from a fused spur 13a max to a 20amp switch rated at 25amp from the ring, sorry its friday and i must have missed something.
 
Could you not use a 3pole fan isoaltor as they are lockable?

Thanks Dillb. Good idea - I've not really searched for 3 pole switches. Do you have a make in mind and would it be suitable (and by that I mean aesthetically suitable) for domestic use? I don't recall seeing anything 3 pole that fits an existing patress...
 
Im with needasparks here.... you stated a sw/fused spur in your opening post that would fuse this circuit down anyway, you have been shown by myself and archy of the option of a standard household sw/f spur by MK that is lockable and although no disrespect to Dillb here but his method contradicts what you originally asked for, can you please enlighten us to exactly you are after Allen?

I'm looking for a lockable double pole switch fused spur!
 
Last edited by a moderator:
Mk do a padlockable 13amp FSU... ive seen the metal clad surface versions but they may do a standard white top version.

Hi Darkwood - thanks for the reply

Apologies for the edits - I'll get the hang of this forum soon!

I've looked at these and they are similar to their white versions. Yes they are indeed padlockable by pulling out the fuse carrier. Unfortunately the requirement is for a lockable double pole isolation and it is possible to switch these (and other makes) with the fuse out which means that it in effect only one pole that is 'locked' out. I've not seen one but I believe it is possible to get a bar which fits through the fuse carrier to stop switch operation but these only count as securable and not lockable (that subtle difference again...).
 
Thanks for the clear-up it was just getting a bit confusing to say the least although on another note when CHP boilers were introduced over 10yrs ago into the uk market they were not allowed to be connected to ring mains and required dedicated circuits.. im not aware of any change to this as if the case was such and derating necessary of a ring fuse then IMHO this should be within the 17th regs and not solely an instruction to derate a ring circuit fuse.... correct me if im wrong.

P.S. what is the make of CHP boiler, id like to read the electrical requirements myself.
 
Any 3 pole fan isolator will fit a standard pattress. Here are a few courtesy of the Forum sponsor Meteor.

<links removed>

Thanks Dilb - again the problem with these is that they are not 'lockable' (as far as I can see anyway) and I could just as easily use a double pole switch as a 3 pole in that case.

I do like the idea of the double pattress idea if there is a suitable lockable switch though as I can place a fuse adjacent to it if needed (ie for connection to a ring)
 
If there is going to be a demand for them, manufacturers will start making them.
They may already have them under way.

Have you tried contacting Mk and the like directly?

That's the plan for next week! Thought I'd ask here first. Will post if I find anything tho and thanks for the reply
 
Thanks for the clear-up it was just getting a bit confusing to say the least although on another note when CHP boilers were introduced over 10yrs ago into the uk market they were not allowed to be connected to ring mains and required dedicated circuits.. im not aware of any change to this as if the case was such and derating necessary of a ring fuse then IMHO this should be within the 17th regs and not solely an instruction to derate a ring circuit fuse.... correct me if im wrong.

P.S. what is the make of CHP boiler, id like to read the electrical requirements myself.

Hi again Darkwood. I'm not allowed to post the link as new member apparently but do a search for Genlec. It's who I work for, and even though the website kind of implies these units are for sale, in reality they are just starting field trials which is why I've been asked to look at on site connection.

The reason for the double pole isolator is rather strange. The current G83 requirements are for 'securable' isolation but the incoming requirements will state 'lockable' isolation. To claim the government feed in tarrif boilers have to be NAPIT inspected and it's NAPIT who have come up with the requirement for this lockable dp isolation ahead of the new regs and apparently have failed any instalation without them for the last 5 years (Basically all the Baxi eco gen units which have been fitted so far have had rotary isolators)) even though it's not a current G83 requirement! (Go figure...). I believe NAPIT are wrong but as it's going to be a requirement soon there's not much point in arguing. As units in field trials won't be claiming feed in I can get away with a securable switch for now!

I'll make a seperate post dealing with derating of the ring circuit as it may be of seperate interest to all - but I've not seen anything in the regs or guidance notes to prevent micro chp being connected to a ring?
 
In response to a comment by Darkwood I've posted this seperately as it may be of interest to others in it's own right...

The best guidance is from the Electrical Safety Council - and it's what MCS and NAPIT apparently follow

http://www.esc.org.uk/fileadmin/user_upload/documents/industry/best_practice/BPG3_11.pdf

Darkwood - in response to your comment about downrating of the ring circuit fuse/mcb have a look at the bottom of page 13 of the guide for the calcs I've had to do. 32A plus potentially 4A from the generator puts us over the rating for 2.5 wiring. The reason I've gone for 25A (it could actually be slightly more) is just that it's an available MCB size for most boards.

Interestingly there is nothing preventing micro chp being wired to an old rewirable fuse proving a double pole RCD is added to the final circuit!

Your comments are most welcome...
 
Thanks Dilb - again the problem with these is that they are not 'lockable' (as far as I can see anyway) and I could just as easily use a double pole switch as a 3 pole in that case.

I do like the idea of the double pattress idea if there is a suitable lockable switch though as I can place a fuse adjacent to it if needed (ie for connection to a ring)
How, exactly do these lock, please?

Some of them have a hole on either side of the isolator, which house a lock. Like the one in the following link.

3 Pole Fan Isolator Switch c/w Pad Lock - White
 
Some of them have a hole on either side of the isolator, which house a lock. Like the one in the following link.

3 Pole Fan Isolator Switch c/w Pad Lock - White

Excellent! That might just do the trick! Thanks for that Dillb - I might just get a gold star on Monday morning (though I very much doubt it! lol) No reason why 6A shouldn't be enough as far as I can tell but will have a think about it and post comments here
 
Hi again Darkwood. I'm not allowed to post the link as new member apparently but do a search for Genlec. It's who I work for, and even though the website kind of implies these units are for sale, in reality they are just starting field trials which is why I've been asked to look at on site connection.

Hi Allan. I've looked at the Genlec website before. Could you, or someone else from Genlec, give us an insider's overview of the CHP product and say how the trials are going (as far as you're allowed to). I'm sure members here would be interested.
 
I've fitted numerous MK iso's as Dillb has mentioned, seem solid enough and have had no problems with them so far. I also have a few lock offs lying around now as most customers don't want them.
 
You could always try putting a key switch in before the FCU if that would meet the requirements for locking off.
Probably more expensive than a fan isolator but worth a thought.
K4780WHi and K1040.jpg
 

Thanks Darkwood - good thought but not sure it would comply. Would have to take advice and/or look up regs as to suitability if the switch has to be easily operated by a consumer. Any idea?

Also did you get to see the guidance notes - do we agree about the connection via spur from ring cct now? I note that PV HAS to be on a radial but micro CHP? Ummm...
 
You could always try putting a key switch in before the FCU if that would meet the requirements for locking off.
Probably more expensive than a fan isolator but worth a thought.
View attachment 14102


Cost wouldn't be a consideration to most women if it meant they didn't have an ugly rotary isolator sat next to the boiler in the kitchen :) Thanks for the idea Richard - will take a look on Monday
 
Hi Allan. I've looked at the Genlec website before. Could you, or someone else from Genlec, give us an insider's overview of the CHP product and say how the trials are going (as far as you're allowed to). I'm sure members here would be interested.

Will have a word with my colleagues on Monday about how much I can say before putting my foot in it...

What I can say is that I've been with company for 4 1/2 years and I've seen the product go from concept to product. The units going on field trials are for telemetry/data gathering, controls operation and reliability tests in a real world environment - all I can say is that they work well in a 'lab' environment. We're all confident that this product can go on to make a big impact on the market (In fact most of us have bought shares in the company from our own pockets!!!) but I suggest you won't see them on kitchen walls for a little while yet.... Watch this space!

In the meantime if you have any specific questions message me and I'll do my best to answer.
 

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Help Please - Lockable DP Isolatorfor Domestic Use
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