Westinghouse Mark 75 HKL & HLM breakers 1

[wbd]

Hello,
I am working in a facility that has older bkrs, West HKL & HLM type. From what I have been able to determine these bkrs have trip units that hat be changed to change trip, for example a 400A Frame bkr can have a 400A trip or 225A trip. One can see what the trip unit is from a cutout on the breaker. What I can not locate is what the instantaneous setting is? It appears that it may be on the interchangeable trip unit which is only accessible by taking the breaker cover off.

does anyone have any experience with these breakers? I have also not been able to find a manual on the trip units themselves.

Thank you in advance.

 

[unclebob]

Sorry I don't have any official papers, but my guess would be, based on the newer C series, that 400 A frames have a fixed Instantaneous at 4000 A, independantly of the rating of the trip unit. Most West, C-H, Eaton frames of 400 A and below have a fixed instantaneous set at 10 times the frame rating.

Bob