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Topic Title: overehead busbar system
Topic Summary: which certificate
Created On: 09 May 2013 08:08 PM
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 09 May 2013 08:08 PM
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tillie

Posts: 754
Joined: 03 May 2006

Hi , I am doing a job in a big printing works at the moment.

All new supplies for the machines are being taken from the 125 amp 3 phase overhead busbar system ( Zuchini ).

I am using fused tap off units that disengage the supply out when you unscrew the cover.

I am uncertain of what certificate to supply for each tap off unit .

Should it be a minor works or an installation certificate.

When I use the underfloor Electrak system I normally only record the highest readings when I tap off and use a minor works certificate but this is normally for multiple floorboxes.

The supplies I am taking off the overhead busbar are for guilotines , laminators and folding machines etc as well as a few sockets.

Could I use a minor works and use the busbar tap off point as my Zdb.

Advice needed.

Regards
 09 May 2013 08:16 PM
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Avatar for OMS.
OMS

Posts: 18930
Joined: 23 March 2004

I'd ask for an EIC and a schedule to cover the supply to the bus bar (as existing) and then treat the bus bar as a big DB and list each tap off as if it was a circuit from that bus bar DB - that way you can capture the tap off outgoing circuit details, cable size tap off protection, R2 Zs etc etc

Regards

OMS

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Failure is always an option
 09 May 2013 08:31 PM
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tillie

Posts: 754
Joined: 03 May 2006

Thank you OMS , then that is what I will do.

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 09 May 2013 08:38 PM
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OMS

Posts: 18930
Joined: 23 March 2004

OK - there may well be other views but as a consultant, that's how I'd be expecting it

It has to be an EIC as it's new circuits (as you have fused bus bar tap offs) - a standard EIC with the bus bar acting as a DB so you can cover it one one schedule would be reasonable.

Note that you didn't install the bus bar under the description - your work is from the client supplied tap offs downstream only

Regards

OMS

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Failure is always an option
 09 May 2013 08:45 PM
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jcm256

Posts: 1794
Joined: 01 April 2006

Almost certain you will be dropping in flexible cable either five core or three core. Will your flexible cable containment be conduit or uinstrut or something attached to the machines? Surely with your experience not a dangle. Does your contract end with the fixed wiring i.e. the bus-bar system or at the machine isolator. Guillotines almost certainly will be subjected to statutory regulations and inspections by competent persons, so I would only give an installation certificate for fixed wiring. Usually fixed wiring would be one contract, the connection of machinery plus machinery earthing, testing of isolators and stop buttons would be a separate contract. As regards your direct question, do not know.
 11 May 2013 06:22 AM
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zeeper

Posts: 1378
Joined: 11 July 2008

so I would only give an installation certificate for fixed wiring.


The best way to think about an overhead Bus-Bar system is to imagine that each tap off box is a way of a distribution board. They have just been stretched out in a long line. And then each tap off box contains the protective device for the Radial final circuit

Normally I would expect a cable from the tap off box to drop down to a local isolator.

I also think with larger cables using ho7 type cables put the bus-bar system under less mechanical stress.
 11 May 2013 08:00 AM
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dickllewellyn

Posts: 1132
Joined: 19 March 2010

I usually find with one particular factory that the next time I visit the machines have all been moved, things unplugged and plugged in somewhere else, and none of my previous certificates makes any sense.... I dread the directors son getting his tool box out! Still. It's their H+S policy that's a at stake!

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Richard (Dick)

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