Use of shunt trip coil Vs UV release in ACB/MCCB:

Are the UV release and the shunt trip ultimately breaking the load on the same set of contacts?  If not you may wish to consider wish you want to wear out by breaking under potential fault conditions. If the  undervoltatge release is just going to fire the same shunt trip anyway, then that is not a consideration, but it allows you to 'test' the UV release when protection fires, however maybe you'd rather not have un-necessary steps in the fault ADS sequence. Also it may make a re-start more sequence specific - clearly the undervoltage lock off cannot be reset until upstream power is on Depending on the nature of the load that may be good or bad - it rather depends why there is a UV lock out at all.

Personally unless there is compelling reason I'd tend to keep things separate, cascaded ADS mechanisms can be a so- and- so to fix when they misbehave because the symptoms may not match the true cause, and you increse the number of points in the chain that may fail, at the very moment when it matters.

Mike

Are the UV release and the shunt trip ultimately breaking the load on the same set of contacts?  If not you may wish to consider wish you want to wear out by breaking under potential fault conditions. If the  undervoltatge release is just going to fire the same shunt trip anyway, then that is not a consideration, but it allows you to 'test' the UV release when protection fires, however maybe you'd rather not have un-necessary steps in the fault ADS sequence. Also it may make a re-start more sequence specific - clearly the undervoltage lock off cannot be reset until upstream power is on Depending on the nature of the load that may be good or bad - it rather depends why there is a UV lock out at all.

Personally unless there is compelling reason I'd tend to keep things separate, cascaded ADS mechanisms can be a so- and- so to fix when they misbehave because the symptoms may not match the true cause, and you increse the number of points in the chain that may fail, at the very moment when it matters.

Mike