AERCO BMK 1000 - Manual (Page 81)

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 6 – SAFETY DEVICE TESTING
OMM-0082_0J AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 81 of 192
GF-130
Ph.: 800-526-0288 05/21/2014
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.
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 6-2: Temperature Limit Switch Location and Setting
See Detail ‘A’
below
Front view with Panel removed
Digital Over-
Temperature
Limit Controller
Reset button
for Manual
Temperature
Limit Switch
Manual
Temperature
Limit Switch
Adjustable
Temperature
Limit Switch
(auto-rest)