Help Please - Lockable DP Isolatorfor Domestic Use

[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

 

[Darkwood]

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.

 

[Allan White]

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)

 

[HandySparks]

Any 3 pole fan isolator will fit a standard pattress. Here are a few courtesy of the Forum sponsor Meteor.

Meteor Electrical Wholesaler |Trade Electrical Supplies | Free Delivery UK and Ireland

How, exactly do these lock, please?

 

[Allan White]

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

 

[Allan White]

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?

 

[Allan White]

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...

 

[Plonker 3]

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

 

[Allan 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

 

[HandySparks]

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

Ah! OK, thanks. Do you happen to know which other makes, apart from MK, can supply the special lock off device required?

 

[Darkwood]

Try this as an alternative.... worth a shot i think...




.http://www.neweysonline.co.uk/mk-el...th-neon/1000006635/ProductInformation.raction

 

[HandySparks]

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.

 

[Strima]

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.

 

[Richard Burns]

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.

 

[Allan White]

Try this as an alternative.... worth a shot i think...
.Buy MK Electric Metalclad Fused Connection Unit, Switched, DP, 13A, With Neon - K963KOALM

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...

 

[Allan White]

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