9013: What is the difference between M1 and M4 options?

FA172956

18/03/2020

Issue:
 M1 and M4 differences

Product Line:
9013 Pressure switch

Environment:
North America

Resolution:
The M4 form is for a Low pressure cut off, the contacts will open at 10 psi below the set cut in pressure. This is used to protect pipe from low pressure collapse in boost pump applications, and pumps running dry in low flow conditions. The  M1 form is  for a  Maintained manual cut-out lever, the switch will stay off when lever is manually set in the off position. The lever will then need to be reset manually to start the operation again.  It is primarily used during extended shutdowns.