Blodgett CB-G SERIES - Manual (Page 19)

19
6.0 ADJUSTMENTS
TO CALIBRATE PRESSURE SWITCHES
Pressure switch range is from 1 to 15 psi.
Adjust all settings to maximum on high signal adjustment screw on pressure switches.
Adjust in the following sequence:
- High limit pressure switch.
- Override pressure switch.
- Operating pressure switch.
- Turning screw clockwise to increase, counterclockwise to decrease pressure.
- Use relief valve to release pressure from boiler for setting adjustments.
1. HIGH LIMIT PRESSURE SWITCHES
Allow pressure to build until unit shuts off. This should occur at 15 psi. Set the high
signal to switch at 14.5 psi on the gauge and the low signal to 13.0 psi.
2. OVERRIDE PRESSURE SWITCHES
Allow pressure to increase to 13 psi. Set the high signal to switch at 13 psi on the
gauge and the low signal to 11 psi.
3. OPERATING PRESSURE SWITCHES
Set the high signal to switch at 11 psi on the gauge and the low signal to 9 psi.
4 Release pressure in boiler to below 9 psi. Burner will come on. Once pressure has
reached 11 psi, burners will shut off. Repeat this process several times to make sure
burners come on at 9 psi and shut off at 11 psi.
Once completed, pressure switches have been calibrated.
Should your unit not have the High Limit pressure switch, start procedure at Override
pressure switch.
SERVICE
Contact your local authorized service office for any repairs or adjustments needed.
WARNING: At least twice a year have an authorized service person clean and
adjust the unit for maximum performance.
NOTE: Pressure switches are factory set. Calibration is only required if pressure
switches are replaced or if adjustment is required.