Can't confirm bonds in hotel complex - what should i do?

[Matt_M]

Good afternoon everybody,

I have recently installed an Electric Vehicle charging station at a hotel complex and couldn't verify earthing arrangements on the site.

The circuit I installed was a 32A radial with a Zs value of 0.24ohms, fed from a db with a Zsdb of 0.16ohms so nothing to worry about there.

The site has it's own 20,000V transformer to which I gained access, however the supply cut out was concealed in its own cabinet which has a padlock protecting the main switch and it looks as though the MET was contained inside it. In order to gain access to the MET I would have had to shut down power to the entire site (which was not going to happen). There were no obvious earth cables entering the supply kiosk (they must all run underground).

The site itself is huge and I have never been there before, the site maintenance man was useless so I couldn't find the sites incoming Gas or Water (or bonds).

How should i certify this?

Many thanks in advance.

Matt

 

[telectrix]

injform the hotel management that you can't issue a certificate until they grant you access. it's their problem if they need to kill the power.get 'em to do a fire drill, then when everone is out, switch off the supply. :smilielol5:

 

[Matt_M]

Thanks for the reply, unfortunately i have left site and it is 95 miles away .

Any other suggestions?

 

[telectrix]

you could run new bonds to as near as you can get to the intake of the service pipes. but, did you not say that you could not access the MET? i would make it clear on your cert that you were unable to access MET and therefore further investigation is required to ensure that the installation is safe.

 

[MDJ]

Can't see the problem myself actually in this case, you did your job right, the readings are fine and the circuit cabling and protection fine, what I would do is certify your works and staple a note to the certificate saying due to access you couldn't confirm bonding and you recommend they have this confirmed ASAP by an approved contractor to satisfy any problems which may relate to insurance claims should there be any incidents in the future. Your covered, they have the ownus on them, look, lets imagine then being asked by lets say london childrens hospital to install a double socket in a corridor for a cleaner, you have no access to any wards or areas due to security except the one where the socket is, now do you refuse to do the job unless you can confirm bonding to gas and water and structured steel and lightning conductor etc????, I think not, get the certificate out with the note and don't worry about it.

 

[i=p/u]

or say can you hoke out past test certificates or periodic inspection papers

 

[Matt_M]

Good answer MDJ !

Running new bonds would be a significant job due to the size of the incomer (50mm bonds!). I also believe incoming gas and water supplies are approximately 30m away from main incomer and would need to be run underground.

I'll go with MDJ's suggestion - Thanks

 

[DKS]

Can't see the problem myself actually in this case, you did your job right, the readings are fine and the circuit cabling and protection fine, what I would do is certify your works and staple a note to the certificate saying due to access you couldn't confirm bonding and you recommend they have this confirmed ASAP by an approved contractor to satisfy any problems which may relate to insurance claims should there be any incidents in the future. Your covered, they have the ownus on them, look, lets imagine then being asked by lets say london childrens hospital to install a double socket in a corridor for a cleaner, you have no access to any wards or areas due to security except the one where the socket is, now do you refuse to do the job unless you can confirm bonding to gas and water and structured steel and lightning conductor etc????, I think not, get the certificate out with the note and don't worry about it.

I would have to agree with Mike here; your reading are good so simply state the limitations and reccommendations regarding the MET and bonding issues (i.e. stating you could not gain access and confirm the ME bonding to services etc & Earthing at the MET... and advise that these are confirmed by an Approved Contractor ASAP). As long as you state what you HAVE done and HAVE NOT done on the certificate with reccomendations you are covered. Like Mike said, put the ownus on the client.

 

[telectrix]

agree with above. basically what i said in fewer words. your a spark, not a miracle worker. they get crucified. make sure you don't. put it all down on the cert.

 

[Engineer54]

Never seen a 20KV transformer in the UK before!! The MET will as you say be in the main switchboard, but i doubt if the bonding your talking about will be in that board, especially if the work you have been doing is remote from this transformer. Each building will have it's own DB/CU it's own EMT, and it's own bonding, so you only need to check the installation from which you gained your supply from!!

 

[johnboy6083]

If it has a dedicated transformer treat it as TNS.

 

[Matt_M]

@ Engineer 54 - I've never seen a 20KV transformer before either but there was a massive sign on it so it stuck in my memory.

 

[Engineer54]

There used to be a 22KV system in the UK, but i'm pretty sure they have all been converted to 33KV and 11KV. Maybe i'm wrong!! lol!!

 

[Guest55]

the OP doesnt actually need access to the kiosk MET , instead locate the incoming gas / water service locations , see if they're earthed and work back from there.

 

[jay sean]

3 letters come to mind LIM

 

[sparkymalarky]

I agree with Jay sean. Make every effort to inspect the incoming services if accessible, if not accessible LIM the heap!