Benchmark 2500 - 3000 Boilers
CHAPTER 6 – SAFETY DEVICE TESTING
Page
76
of
204
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0094_0E
03/20/2014
Ph.: 800-526-0288
GF-137
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 6-3.
Water Temperature Fault Test
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 6-3: Temperature Limit Switch Location
ADJUSTABLE
TEMPERATURE
LIMIT SWITCH
MANUAL
SWITCH
RESET
BUTTON
OVER
TEMPERATURE
LIMIT DIGITAL
CONTROLLER
MANUAL
TEMPERATURE
LIMIT SWITCH