Water Temperature Fault Test - Benchmark BMK 1500 User Manual

6.5 WATER TEMPERATURE FAULT TEST

A high water temperature fault is simulated by adjusting the automatic over-temperature switch.
This switch is accessible from the front of the unit as shown in Figure 6-2.
1. Start the unit in the normal operating mode. Allow the unit to stabilize at its setpoint.
2. Lower the adjustable over-temperature switch setting to match the displayed OUTLET
TEMPERATURE.
3. Once the adjustable over-temperature switch setting is approximately at, or just below,
the actual outlet water temperature, the unit should shut down. The FAULT indicator
should start flashing and a HIGH WATER TEMP SWITCH OPEN fault message should
be displayed. It should not be possible to restart the unit.
4. Reset the adjustable over-temperature switch to its original setting.
5. The unit should start once the adjustable temperature limit switch setting is above the
actual outlet water temperature.
6. Once the adjustable over-temperature switch setting is approximately at, or just below,
the actual outlet water temperature, the unit should shut down. The FAULT indicator
should start flashing and a HIGH WATER TEMP SWITCH OPEN fault message should
be displayed. It should not be possible to restart the unit.
7. Reset the adjustable over-temperature switch to its original setting.
8. The unit should start once the adjustable temperature limit switch setting is above the
actual outlet water temperature.
Figure 6-2: Temperature Limit Switch Location
OMM-0097_0C
GF-142
Benchmark 1500 - 2000 Boilers
CHAPTER 6 – SAFETY DEVICE TESTING
Water Temperature Fault Test
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
OVER
TEMPERATURE
LIMIT DIGITAL
CONTROLLER
ADJUSTABLE
TEMPERATURE
LIMIT SWITCH
MANUAL
SWITCH
RESET
BUTTON
MANUAL
TEMPERATURE
LIMIT SWITCH
Page 73 of 184