Columbia CT Series, Installation, Operation And Maintenance Manual

Page: 38 / 72

FM-148 COLUMBIA BOILER COMPANY, REV 6-06
- 35 -
Danfoss Operating Pressure Control
Testing While in Operation.
1. Start the burner and allow the boiler pressure to rise to the main set point. The
burner should shut off.
2. Open the steam valve and relieve pressure until the pressure is below the lower
set point. the burner should now start. The lower set point is determined by tak-
ing the differential from the main set point.
Testing while not in operation.
1. To test operation of pressuretrols while unit is not in operation requires the use
of an external source of pressure such as an air compressor.
2. Close all valves and connect the pressure source to the boiler.
3. Increase the pressure in the boiler until the pressure is higher than the setting on
the controller. The mercury switch should rock over such that continuity is now
broken.
4. Decrease the pressure in the boiler until the differential is satisfied. The mercury
switch should rock back to a position that causes continuity to be made across
the switch.
Danfoss Safety Limit Pressure Control
Testing while in operation.
1. Adjust the safety limit set point below the main set point.
2. Start the burner and allow the boiler pressure to rise to the safety limit pressure
level.
3. The burner should shut off and not restart until the manual reset lever is
depressed.
Testing while not in operation.
1. To test operation of pressuretrols while unit is not in operation requires the use
of an external source of pressure such as an air compressor.
2. Close all valves and connect the pressure source to the boiler.