information on vacuum medium voltage contactors

[Pafi]

I'm looking for information regarding reliability of the medium voltage vacuum contactors type JCZ5 produced by
GUOGUANG ELECTRIC CO., LTD. CHENGDU,from China.
They are really cheap, I just don't know how reliable they are, especially because I intend to use them in back to back automated capacitors banks. If someone has this information, or has other information regarding reliable medium voltage contactors - and if they are also cheaper - please contact me.
Lucian - elness@xnet.ro

 

[melone]

Did you talk to the manufacturer?

 

[Pafi]

Yes, I talked to the manufacturer. I didn't obtain all the data I needed to make the calculation, just his advice will work with capacitors. Because the manufacturer is not a name and the medium voltage contactors are still expensive, I wanted a second opinion, he said he exported in US, Australia and Taiwan.
Thank you for the answer.

 

[jraef]

Our company is currently testing them out for motor control use. We have set up an automated cycle tester and a load bank, testing them at low voltage, rated current, high duty cycle. So far so good, but it has not been long, maybe 2 weeks. Check back in this thread and I'll post our findings. I can't attest to their use in capacitor switching, but I will be curious to here as well.

Quando Omni Flunkus Moritati

 

[Pafi]

Thank you jraef!
I understood you have checked the low voltage vacuum contactors (or the medium voltage?). I'm waiting the test results from you. If I decide to buy and use them, I shall share the information with you as well. To be onest, I'm affraid to take that chance, in capacitors switching the conditions are rough for contactors.

 

[1x1x1x]

Pafi,
The capacitor switching is a very harsh mode for any mechanical device. The pre-strike and the re-strike phenomena are well known in the industry and the device shall be capable to cope with it. My recommendation is to ask any vacuum contactor manufacturer to provide a certified test reports that their vacuum contactor or breaker is capable to switch capacitors without problems. You should also ask what the capacitor bank configuration was during the test (i.e. D or Y configuration etc.), and make sure your application is a similar.
The price is not only the point when one selects a contactor for capacitor switching.