multilinnoob
Electrical
- Nov 27, 2015
- 4
Hello Everyone!
I am looking to upgrade my Multilin 269+ motor protection relay with the newer Multilin 369 relay. While analyzing the drawings, I observed that presently, the 269+ is wired up such that the normally closed contacts 30 and 31 feed the motor main contactor (M).
I am unsure if this is programmed to be a fail safe (FS) or a non fail safe (NFS), so I do not know what will happen on loss of control power. However, I do know that if there is an undervoltage condition, the relay will trip out.
I am not certain what I should assign as my relay trip contacts in 369. From the user manual, I understand that a FS contact changes state when power is lost to the relay, while a NFS contact does not.
So, how do I choose my trip relay contacts? NO or NC, which ones should be FS or NFS?
Also, if say I assign the NC trip contact as FS, then will it change state when powered up?
I am looking to upgrade my Multilin 269+ motor protection relay with the newer Multilin 369 relay. While analyzing the drawings, I observed that presently, the 269+ is wired up such that the normally closed contacts 30 and 31 feed the motor main contactor (M).
I am unsure if this is programmed to be a fail safe (FS) or a non fail safe (NFS), so I do not know what will happen on loss of control power. However, I do know that if there is an undervoltage condition, the relay will trip out.
I am not certain what I should assign as my relay trip contacts in 369. From the user manual, I understand that a FS contact changes state when power is lost to the relay, while a NFS contact does not.
So, how do I choose my trip relay contacts? NO or NC, which ones should be FS or NFS?
Also, if say I assign the NC trip contact as FS, then will it change state when powered up?