Frequent failure of 3 phase monitoring relay

Hello Colleagues,

We have a 3phase monitoring relay(ABB CM-PAS) is being failing very frequently. The auto reset function is not working and I have to raise the Asymm settings up to 20% to reset the alarm and return it back to the desirable value. This issue was repeated in more than 6 relays in different locations.

Did anybody face similar issue before? Is there a recommended reliable type to be used instead on the above mentioned type? Is the digital monitoring relay is better to be used that the analogue ones?

Regards,
Mahmoud Diaa
 
I got this problem as well,
Mine relay was schneider electric and it never worked for me, I thought maybe the neutral flaoting causing this, measure your phase current and try go balance the neutral to zero apms
 
Those of Schneider were used in our Spanish factory because in that factory they were more or less "married" to Telemechanique.....
In the controlpanels we moved from other factories to Spain were the Eberles, they didn't break down, but the Schneiders did: unneccesary switch a 1MW kiln off with 20.000 Guilders of product inside.
Lateron also the Schneiders were replaced with the Eberles and they never had the unneccesary switch offs again.
 
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