Nuiance tripping of MICROLIGIC 5.0 P 1

[suriae]

We're building 8 vessels and using MASTERPACT NW ACB with STR58U trip system for our generators. After the delivery of vessel no.2, the Maker of ACB informed us to install MICROLOGIC 5.0P because STR58U is out of production,which we agreed,however we have this nuiance tripping "AP" indication (vessels 4,5 and 6) which we never experienced before. Anybody out there having similar problem with MICROLOGIC 5.0P?

 

[DanDel]

Per the manufacturer's manual:

"Ap self-protection/advanced-protection indicator
light lights when the advanced protection
features cause a trip to occur, the trip unit
overheats, the instantaneous override value is
exceeded or a trip unit power supply failure
occurs."

The Advanced Protection functions on this unit consist of many elements, including current or voltage imbalance, reverse power, load shedding, phase rotation, etc.

You should probably check which of these settings are being used and determine if they are necessary and/or if the settings are correct.

The link to the manufacturer's manual is:

http://ecatalog.squared.com/pubs/Ci...nits/Micrologic Trip Units/P/48049-137-04.pdf

 

[suriae]

Thanks DanDel, in addition to your advice, I received info from the Maker that they acknowledged MICROLOGIC 5.0P has inherent problem regarding EMC. Trip unit built after week 50 of 2005 is verified to have full or reliable electro Magnetic compatibility by adding capacitor. We will conduct full test on the ACB soon the Main Switchboard is ready.If it is true that Maker corrected the problem we will ask them to differentiate which MICROLOGIC is built after week 50.