Can I still buy mechanical relays?

[ukgraduate]

Hi I am after a single phase,self powered overcurrent relay, preferably with definate time.

I want to use this to measure the current on the earth connection of a 13.8kV zigzag transformer. It is in a remote area and dont have (or dont want) to have auxilary power.

The self powered relays I have seen seem to be powered by via the CT (hence current needs to be on all the time to be powered). However in this instance there should be no current except when there is a fault


Does anyone know either a relay sutiable or where in the US I can buy old mechanical style?

 

[davidbeach]

I believe that GE and ABB will still gladly sell you an IAC or CO relay.

 

[davidbeach]

But, what will you use to trip the transformer if you don't have any station power?

 

[waross]

What are you trying to accomplish? The old over current relays were mostly instantaneous or inverse time. The basic overload relay would respond to an over current by providing a normally closed contact opening. Many models also gave a contact closure.
The old mechanical breakers used a heating element that was heated by the passage of the current. The heat may act on a bi-metal strip or on a low temperature melting alloy. There are also other types of mechanism.
Do you want to provide an alarm signal, do you want to trip a breaker. Do you want automatic reset after a trip?
If you want to give us a complete description of your problem you will probably get a complete answer.
If you give out information in bits and pieces, you can expect a fragmented answer, and some of the more knowledgeable members may loose interest an not bother responding.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[stevenal]

Basler makes a self powered single phase overcurrent relay (BE1-50/51) designed to replace electro-mechanical relays. Check with Basler (or davidbeach?), but I believe it is similar to an electro-mechanical relay in that it does not need to be powered continuously to function. I tried to verify on the Basler site, but I guess my account expired.

 

[krisys]

The old legacy electromechanical protection relays may be available. But at what cost and to achieve what. Now the legacy relays would be charged higher than the popular digital relays for the comparable protections. So think over before going for the legacy relays.

 

[ScottyUK]

I'm fairly sure that Areva are still making copies of the old GEC designs at their factory in India. Possibly not the full range.

 

[tinfoil]

Ask your local power utility.

I know that we are scrapping those things on a regular basis.

 

[Zogzog]

http://www.cbstore.com/Catalog/ByType/ProtectiveRelays

 

[JG2828]

ABB still sells many Electromechanical relays.
You could also search EBay if you want to purchase a used relay. Just search ABB CO relay and lots of them come up.
If you dont mind an older relay you could search EBay for Westinghouse CO relay.