Vacuum problems?

[Thugfarmer]

I just ran my first blast of shatter, while purging the chamber is at full vac and closed from the pump, but it seem to be working better opened and on. Can it stay closed and do its job? I just don't want to burn up my pump. Thanks for some advise?

 

[Jack og]

Purge is on 24/hrs min, 2 (stage) speed 3.5 cfm Units can run hours or days without burning out.