Phase Disagreement Protection

[karalahana]

Hi,I saw in a specification booklet of a 154 kV circuit breaker a clause which calls for a" phase disagreement protection " in the 154 kV circuit breaker, first can there be an integral protection scheme or must be it a separate relay in the control box of this circuit breaker? ?f so there is needed to have current data from the contacts is it true? ?s this kinda protection inherent with all high circuit breakers?

 

[slavag]

Hi.
For my opinion it's very simple protection for the single-phase CB.
All three phases must be closed or opened.
Stadnard solution is :
3 NO contact in parallel in series with three NC contact in parallel and conected to timer, timer closed contact and send trip do trip coil 2.

Possible build such functionaliti in the any digital controller with current criteria.
Hope it help.
Best Regards.
Slva.

 

[karalahana]

is phase disagreement protection and phase discrepancy protection same?

 

[marks1080]

I would assume it is. I've never heard of it referred to as phase disagreement protection. If you had rolled a phase, other protections will pick it up!

 

[karalahana]

yes slavag,I looked up google guy, so I think some relays has featuring such a protection, if preferred it might be as easy as you told, but it could be achieved too by relays (I think this option wont be more reliable than what you advised...)

 

[marks1080]

You really don't have a choice but to use the pallets from the breakers for this. You can input that information into an IED relay, or just simply make a control circuit to trigger an alarm.

 

[karalahana]

yes it sounds goood...