Bussbar Flash Testing

[dodge26]

We have had to get a specialist company who repair bussbars, it is rising main bussbar 1200amp, they do alot of work for the rails, but do not carry out any flash testing, as it would be carried out on site. Can anyone advise what sort of flash test is needed, and better still anyone know someone who can provide this service, based in South London, but would happily come across with the piece within a couple of hours from here.

 

[AndyOz]

In my opinion there is no need to carry out a flash test on site. It is likely to cause more problems than it will solve. A 100V IR is quite sufficient. A further low ohm ducter test will highlight any high resistance joints.

 

[Darkwood]

I assume your 100v is a misprint

 

[AndyOz]

Well spotted ..... Should be 1000V

 

[Knobhead]

On an isolated section I would test at 2500V between phases and 1000V to earth for one minutes. Any joints in the section need to be tested with a micro ohm meter (Ductor). The figures for the Ductor tests are available on the web if you know the CSA of the bars. A HiPot flash test results in damage if it fails.

 

[dodge26]

Thanks for the information. Anyone know anyone who does this in the South East??

 

[Knobhead]

Hire a 5KV Megger and do it yourself. Simple as.

 

[Engineer54]

What tests did this specialist contractor perform on the renovated rising bus bar installation?? I can't believe they left the site without performing any testing of their work!! If the manufacturer of this bus bar system is a well known manufacturer, and still in business, you should be able to get all the associated test requirements and data from them, which makes life just a little easier all round!! lol!!

What type of construction is this rising bus bar system??

Any tests that you perform, ensure that any electronic protection devices (including modules within OCPD for example) are out of circuit. The main areas to be concerned with are, the bus bar joint connections and Tee off connections at each of the floors. As Tony said, test with a 4 contact micro-ohm Ductor tester that can deliver a minimum of 10A (preferably more) into the test area. A 5KV IR tester should be more than capable of finding any insulation problems. Always use the instruments guard lead, to ensure your seeing the accurate values of the tests your performing...

 

[Knobhead]

To be honest, I shouldn't have suggested hiring a 5KV Megger. Yes they can be hired, but can the operator use it safely? Very doubtful. E54 mentioned the guard lead, that got me thinking about the safety and competence for testing.