Watts Benchmark Aerco OMM-0122 - 4.7.1 Digital Alarm Switch Checks and Adjustments

Benchmark 750-3000 Boiler Installation & Startup Manual
SECTION 4 – INITIAL START-UP
OMM-0121_D • GF-205 • 5/9/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 75 of 122
4.7.1 Digital Alarm Switch Checks and Adjustments
The Over-Temperature Alarm switch settings can be checked or adjusted using the controls
and display on the front panel of the switch illustrated and described in Figure 4-7 and
Table 4-9.
F
Alarm
RST
SET
Limit Control
Figure 4-7: Digital Over-Temperature Alarm Switch Front Panel
TABLE 4-9: Over-Temperature Alarm Switch Controls and Display
CONTROL/DISPLAY
MEANING
FUNCTION
LED Display
TEMP status
Displays current water temperature or setpoint.
RST
RESET Button
Resets the unit after an alarm condition.
UP Button
Increases the displayed temperature.
DOWN Button
Decreases the displayed temperature.
SET
SET Button
Used to access and store parameters in the unit.
Perform the following steps to check or adjust the Over-Temperature Alarm switch settings:
Over-Temp Alarm Switch Check and Adjustment Instructions
1. Set the ON/OFF switch to the ON position.
2. Press the SET button on the Over-Temperature Alarm switch. SP
will appear in the
display.
3. Press the SET button again. The current over-temperature limit value stored in memory will
be displayed. (Default = 210°F, 98.9°C).
4. If the display does not show the required over-temperature alarm setting, press the ▲ or ▼
arrow button to change the display to the desired temperature setting.
5. Once the desired over-temperature alarm setting (210ºF) is displayed, press the SET
button to store the setting in memory.
6. To calibrate the offset (P1), press and hold the SET button on the Over-Temperature Alarm
switch for 8 seconds. Access code value 0 should appear in the display. The switch comes
from the factory with the code set at 0. AERCO recommends that you do not change this
code.
7. Press the SET button again to enter the code. The first parameter label, SP, will appear in
the display.
8. Using the ▲ and ▼ arrow keys, select parameter P1.
9. Press SET to view the value stored in memory.
10. If the desired value is not displayed, modify the setting using the ▲ and ▼ arrow keys. The
value can be changed from -10° to +10° (-5.5°C to + 5.5°C) offset. Press SET to enter the
value and exit to the text parameter.
11. To exit the programming mode, press the SET and ▼ buttons simultaneously or simply
wait one minute and the display will automatically exit the programming mode.
12.
Once the programming mode has been exited, the display will show the current outlet
water temperature of the boiler.