MCS non-conformity

[blades1898]

We had our MCS inspection last week and recieved one non com for our a.c isolator next to the fuse board. We used an all in one wylex unit that incorporates a double pole switch, a rcbo, and then the meter. We previously worked for a large company and thats all they ever used and have done 100s of installs using this unit.The gaffer at the large company had checked to see if this could be used and was given the green light(not sure who told him wether it be wylex,wholesalers or mcs).The Wylex unit is lockable and comes with the sticker "main a.c isolator" we tried to argue the point with the assessor but to no avail, he tried to get the dti guide up on our p.c but it wasnt available.We have since looked and i havnt checked the b.s number yet apart from that the only other thing that could go against this unit is that, in the dti guide it says lockable with a standard padlock.We have contacted our wholesaler about this to have a word with the wylex rep as they could be mis selling this unit or maybe they think its acceptable.We have since fitted a rotatory isolator above the wylex one and sent evidence off, we were about 5 mins from passing first time.Cant see us using this unit now it did save time but theres no point fitting it if you need a rotatory one next to it.
Anyone using these units? Is the inspector right?

 

[moggy1968]

I have had reservations about these isolators since they came in. I don't think a toggle type switch does the job as it requires a special type of lock rather than just a padlock. We thought about using them but decided against it.
Unfortunately the country is full of installs done by companies who 'have done hundreds' who read the book and think that means they know it all when they have little or no knowledge of the electrical business. I know, I've worked for a few!!

 

[MorganPVI]

Your assesor and moggy1968 is dead right, the toggles need a propriety lock, it does say in the DTI guide a "non propriety" lock must be used. i.e padlock.

 

[BruceB]

What I do not think you have said above is whether you do have a standard lockable ac isolator by the inverter? Have not checked, but my recollection from last time I looked is that provided you have an accessible lockable isolator somewhere, then the wylex or equivalent unit elsewhere was compliant.

 

[blades1898]

Reading the dti guide it does says standard padlock so really we have accepted it and moved on. Interesting point that bruce we have fitted a ac isolator next to the inverter.

 

[BruceB]

I have re-read the DTI guide, particularly 2.3.2. In my opinion a single ac isolator compliant with the relevant BS, properly labelled, that can be secured by a normal padlock is fine provided it is accessible. So in a utility room or cellar probably fine, but in a loft where you have to get a ladder out is probably stretching the meaning of accessible.

But if it is your first assessment just bite the bullet and move on as you say.

Edited to add I have also looked at the latest versions I have of DTI Guide V3 and G83/2, neither of which are formally issued yet as far as I know. The wording in both on this point is arguably less clear that in the current DTI Guide so we will have to wait and see where they finally go on this point.