Do railroadstill use glass-encased relays?

[Robert Gift]

Was told thathey need to be tested every month.
On little vibration-absorbing springs, they are impressive to see, but have they been replaced by morefficient, non mechanical solid-state relays?
Thank you.

 

[roee]

Railroads have hundreds of thousands of glass relays still in service. They do not need to be tested every month, that would be crazy. Relays are tested every 2 or 4 years depending on the type. Searchlight signals (which is a glass relay) is rocked every 6 months to ensure that it still works properly, but they are on a 2 year test schedule.

 

[NM_RailNut]

The only real advantage to solid-state relays would be reduced power usage and wear and tear; those aren't really issues in this application as the equipment controlled by the relays doesn't use a tremendous amount of current (and neither do the relays themselves) nor does it operate continuously. Glass-encased relays work just fine.

 

[roee]

The only real advantage to solid-state relays would be reduced power usage and wear and tear; those aren't really issues in this application as the equipment controlled by the relays doesn't use a tremendous amount of current (and neither do the relays themselves) nor does it operate continuously. Glass-encased relays work just fine.

The real advantage of getting away from relays is 1)reduced testing, and 2) better reliability. Relays are mechanical devices and they fail. And for the testing, relays need to be tested every 2 or 4 years, and in a large interlocking with 100 relays, that takes lots of time, and if it's a busy area, even longer trying to get track authority to do the testing. That is not required of solid state equipment.

 

[railsnw]

Relays

Most relays are now of the plug in style so you don't have to hook up wires as you do on a glass case relay.

Richard

 

[roee]

Most relays are now of the plug in style so you don't have to hook up wires as you do on a glass case relay.

Richard

I think he means just relays in general. Even the shelf mount relays aren't glass anymore. But shelf mount or plug in, they all need to be tested every 2 or 4 years depending on the type of relay.

 

[NM_RailNut]

The real advantage of getting away from relays is 1)reduced testing, and 2) better reliability. Relays are mechanical devices and they fail. And for the testing, relays need to be tested every 2 or 4 years, and in a large interlocking with 100 relays, that takes lots of time, and if it's a busy area, even longer trying to get track authority to do the testing. That is not required of solid state equipment.

All true, and I wasn't even thinking about the testing issue (which is rather stupid of me, given my own background). In a situation like that solid state is the only way to go.