Hi pot adaptors

[australiantroubleman]

[I] am wondering if any Australian power companies have tried using hipot adaptors on phasing gear on Hazemeyer or similiar equipment with easy primary access.

The american elbow type installations are completely different , I am wondering if those UG fault finding techniques have been trailed or used on English / european distrubution systems using discrete switchgear not elbows.

Also interested in how long it takes to charge up a long or cable of high capacitance via one of these diode type testers.

Any experiences would be appreciated.


Thanks

[lewy]

We don't just use them on elbows, but also on switches.
They charge up the cables pretty much right away.
I find they work better on the higher voltages.

[australiantroubleman]

Thanks Lewy ..

Does it matter if the cables are multicore or single conductor , cables belted or screened ?

Are there any cable or termination styles that cannot be Hipotted?


Thanks Again?

[topgroove]

I'tl work on all cables... If you have URD lightning arrerstors on the system It will give you problems though.

[Lineman North Florida]

I'tl work on all cables... If you have URD lightning arrerstors on the system It will give you problems though.

Yeah it'll show a fault everytime until you pull the elbow arrestors or untap the other variety of URD arrestors, does the same thing when cable is left on transformer instead of isolated on parking stand or feed thru.

[jozmo]

Be sure to discharge the cable after your test.

[australiantroubleman]

So La,s or lightning arrestors can cause problems , no transformer primaries to be in circuit ( we use delta connections only so im not sure if this still causes problems ).

And discharge each phase before testing the next phase ,I assume this minimises voltage extremes existing on adjacent phases charged to peak voltage .

To discharge the cable you remove the hipot adaptor and discharge the cable through the phasing sticks? Or apply grounds or park the elbow onto a ground.

On our system we dont use elbows ,all cables are terminated onto switchgear , some switchgear types allow easy primary access we would have to build suitable adaptors to allow safe hipot injection to be utilsed. And methods to allow quick and effective grounding of each phase during tests.

These ideas make good sense and im trying to get my company to adopt Hi pot testing instead of the "try back till you find it " dinosaur methods being adopted at the moment .

Thanks again for your experiences as I need all the information to convince managers and engineers these methods can be adapted ..

[duckhunter]

You anger the members by testing with a fuse and you break down the conductor. I like overtime once in a while, but I hate finding the faults on UG. Especially this time of year. Once you find the bas spot, you have to plow snow to dig up the failure, and if it's near the road, or in a gravel road or driveway you have to deal with 3 feet of frost.

Are you using thumpers or radar for finding the faults in Australia?

[Trojan]

Quote:
Originally Posted by topgroove
I'tl work on all cables... If you have URD lightning arrerstors on the system It will give you problems though.
You might get bad readings on multiple conductor cable (3 conductors under same sheath).