hospitality trailer

[singingfraggle]

Hello guys can anybody confirm my thoughts or is there something I am missing .The company I work for have just bought a hospitality trailer the trailer is about ten years old no electrical certs with it only pat test certs. I been asked to give it eicr on checking the dis board the whole board is protected by a 100a 300ma rcd no rcbo,s after that . now I thought that the supply cable could be protected by that and all circuits should be protected by 30ma . now as this has been in use for many years am I missing something or was this just bought from a pr hire company who never bothered checking many thanks Paul

 

[chrish_1977]

It may be classed as a TT system as the ze will change wherever the thing is "plugged" in, all you can do testing wise is dead tests, as all the live testing results will change depending on how the trailer is fed

 

[davethsparky]

I can't follow how you make the assumption it is going to be supplied by a TT system? If it's going to outdoor events supplied by generators it will almost certainly be supplied from a TNS system.

As far as testing goes your best bet is to view it as a very big and complex appliance and test it accordingly. You will have to make it live to test the RCD(s)

I would be looking to bring the installation in the unit to meet the current regulations as you never know what the quality of the supply will be at any event site. If it turns up at an event where I am doing the power distribution it will get put on its own 30mA or possibly 10mA RCD supply if i'm not 100% certain that it has the necessary protection in it.
And if there is any doubt about it's electrical safety it won't get any supply at all.

 

[Brightspark2]

Add 30mA protection to the circuits that need it. As said if it's mobile then the supply will change on each site and will need to be tested on each set up...

 

[Dizzy_Maskell]

I think if it is plugged in then so long as it has a valid PAT sticker it will be fine

 

[Guitarist]

I think if it is plugged in then so long as it has a valid PAT sticker it will be fine

Best answer on the forum for ages... :clap:

 

[davethsparky]

HAHAHA, I hope you are joking.

If one of these trailers turns up with just a little green sticker as the only proof of safety on one of my events they'll have more luck rubbing two sticks together to get heat than they will of getting any power from our supply!

 

[tazz]

HAHAHA, I hope you are joking.

If one of these trailers turns up with just a little green sticker as the only proof of safety on one of my events they'll have more luck rubbing two sticks together to get heat than they will of getting any power from our supply!

Dont worry....they have 3ft x 3ft green pass stickers just for trailers

 

[davethsparky]

I'm not worried, i've got a big green landrover for removing said trailer, big green sticker and all!

 

[chrish_1977]

I can't follow how you make the assumption it is going to be supplied by a TT system? If it's going to outdoor events supplied by generators it will almost certainly be supplied from a TNS system.

As far as testing goes your best bet is to view it as a very big and complex appliance and test it accordingly. You will have to make it live to test the RCD(s)

I would be looking to bring the installation in the unit to meet the current regulations as you never know what the quality of the supply will be at any event site. If it turns up at an event where I am doing the power distribution it will get put on its own 30mA or possibly 10mA RCD supply if i'm not 100% certain that it has the necessary protection in it.
And if there is any doubt about it's electrical safety it won't get any supply at all.

The last event I went too, the majority of generators attached to said trailers all had an earth stake, hence the comment about it being TT,that's just my opinion as the op hasn't mentioned what will be supplying the trailer

 

[davethsparky]

The last event I went too, the majority of generators attached to said trailers all had an earth stake, hence the comment about it being TT,that's just my opinion as the op hasn't mentioned what will be supplying the trailer

That's not a TT system, a normal set-up with the generator spiked to earth is TNS

 

[chrish_1977]

Even the spike at the unit?

 

[davethsparky]

Spike at which unit?

The generator has the neutral and earth linked and referenced to earth via an earth rod, this forms the source of the supply. The first two letters refer to the source so we get TN for the first part.
You then distribute 3 phases, neutral and a Seperate earth from there around the site, this gives you the S part therefore the supply is TN-S.

For it to be a TT system you would have to omit the distributed earth and use an earth electrode at the trailer to give an earth return path through the earth.

TT = earth electrode BUT earth electrode does not have to = TT

 

[Engineer54]

So what would you call a generator that has what is known as a ''Floating Earth''??
In fact, most portable generators under 10 KW will have this earthing arrangement!! Such rated gen-set's will also be without an AVR to stabilize output voltage!!

So let's not forget, that all generators are Not Equal!! lol!!

 

[davethsparky]

Personally I call them noisy and a pain in the arse when they turn up on my events.

We are talking specifically about generators for events here, and so we are in the realms of bs7909 which requires anything over 6KVA to be referenced to earth. And realistically any event where hospitality trailers are turning up is going to be fed from something more than 6KVA