Power to my garage

[bushynut]

I'm doing some work in garage and shed (Part-P I know), but I'm just trying to understand what these classes mean?

Is this right?


class 1 - Normal ceiling rose/ batten holder, knockout box/ Pattras?

class 2 - Double insulated fitting i.e. No earth required?

class 3 - I'm not sure

 

[Adam_151]

There isn't a class 3, there is a class 0 though, thats metal cased, no earth and not double insulated, its not allowed in this country as it only takes a single fault to make the case live, but is used in places like india

 

[Spark123]

I thought class 3 is equipment relying on protection from a SELV source.

 

[bushynut]

Ok, the socket outlet is going to be SELV socket BS EN 60309-2 25V

and I've decided that the lighting (2 bulkheads) will be to class 2.

Now I know the garage will be classed as Zone 2, but the inspection pit (thats what I'm going to dig) Me thinks should be classed as Zone 1.

That sound good?

The socket by the way is just for an inspection lamp

 

[ban-all-sheds]

Now I know the garage will be classed as Zone 2, but the inspection pit (thats what I'm going to dig) Me thinks should be classed as Zone 1.

 

[Qedelec]

So the pit is going to be filled with water and used to bathe in?

 

[Adam_151]

So the pit is going to be filled with water and used to bathe in?

That'd make it Zone 0, Qed the area area the pit would be zone 1 though , the OP should note that his garage now counts as a bathroom, and so requires suppplimentry bonding

 

[bushynut]

So what would the garage be classed as then?

The garage is going to have by the way a 6 way DB (TT) with 30mA RCD.

1 x 32A MCB for the Final ring circuit

1 x 6A mcb for the lighting

1 x 6A MCB for the lighting to the pit

1 x 32A MCB feeding a step down isolating transformer for the SELV socket in the pit

the circuits to the pit will be in heavy gauge screwed conduit (vapour proof) which will be screeded over

the two remaining spaces on the DB arefor outside lighting and electric garage doors in the future.

Now, if the garage/ inspection pit was flooded (I live in a high risk area!) the class II bulkheads would be ok. Is the classification for the pit being Zone 1 correct? and the rest of the garage zone 2?

Please, please, please don't take the P*ss out of me. I'm a relatively experienced DIYER I just wnat to make sure that the garage will pass an inspection.

 

[Spark123]

Imho I don't really think you need to be looking at this as a bathroom or a swimming pool, are you really going to be swimming/bathing in the pit when it is full? Nethertheless, you still need to design it to withstand its environment, if it is to be submerged, you need to make sure the electrical system is suitable for this purpose, i.e. the light fittings need to be IPX7 or IPX8. The cables, glands etc also need to be the correct type and suitable for submersion.

Is there any other way of stopping the pit from being submerged?
Although not ideal, it may be better to use portable lamps which can be removed from the pit when not in use, keeping the electrical system out of the pit.

32A @ 240v for a handlamp selv transformer??? 25v # 300A!!!

 

[bushynut]

I work away and my brother will be using the garage as a temporary place of work.

All I want to do is when the house isn't being occupied is that if there is any flooding in the area that it won't effect the lighting and socket outlet within the pit.

I will have a couple of gerry cans full of petrol in the garage stored, for commercial use (I live in the sticks), thats why I need the pit to be protected from the chance of 'Sparking', when my brother turns up to use the garage while I'm away.

What kind of transformer will I need for a SELV (BS 60309-2) 25v socket (violet in colour) outlet. Its just for an inspection lamp purely as the tools my brother will be using in the pit are air powered via a generator (gerrie cans).

p.s. Can I run in the same conduit the lighting circuit as well as the SELV circuit or will the SELV need to be seperated?

Please don't mock me I am a DIYER with a decent amount of experience in domestic wiring, its that this is a little new to me (garage/ SELV)

 

[Spark123]

Explosive location?
If what you are saying is correct, you now need to go intrinsically safe as well which is probably way OTT for you!!!
This is a prime example where it may be better to remove the risk rather than to try and control it, is it possible to remove the said cans of petrol to a safe isolated location?
SELV does not stop sparking, it is a form of protection against electric shock. Consideration should also be made to things tools i.e. grinders wether air powered or not.

 

[bushynut]

Both my cars are in the garage, a ford cortina and an old triumph aclaim, don't ask why. These cars as you can imagine are being done up, so leakages of liquid is in inevitible

In the inspection pit the bulkheads for the lighting are class II with the conduit (steel/ galvanised/ black enamel) will be vapour proof including glands, etc.

The garage has a small room which I use to grinders, drilling etc, in.
In the garage the petrol will have a constant presence, it can't be avoided.
what I need to know is can I use the conduit to run both circuits in, (lighting and the SELV socket outlet)

What type of transformer I'd need for the SELV socket outlet (25v), the MCB will be a 'B' type but what rating, or could I spur it off the lighting circuit (unlikely i know)

 

[andy]

what I need to know is can I use the conduit to run both circuits in, (lighting and the SELV socket outlet)

What type of transformer I'd need for the SELV socket outlet (25v), the MCB will be a 'B' type but what rating, or could I spur it off the lighting circuit (unlikely i know)

keep mains and SELV seperate.

see this for more info on SELV transformers

 

[bushynut]

Can the lighting circuit and socket circuit share the same conduit until the circuits reaches a 'T' box where they seperate. 'T' box to the transformer and the lighting circuit to the switch

Thanks in Advance

 

[andy]

Can the lighting circuit and socket circuit share the same conduit until the circuits reaches a 'T' box where they seperate. 'T' box to the transformer and the lighting circuit to the switch

Thanks in Advance

yes. just aslong as LV and SELV are together there shouldnt be a problem