Over-Temperature Limit Switches; Adjusting The Automatic Reset Limit Switch Temperature - Watts AERCO Benchmark OMM-0136 Operation And Service Manual

Benchmark Platinum-Edge [II]: Operation-Service Manual
SECTION 4 – INITIAL START-UP

4.7 OVER-TEMPERATURE LIMIT SWITCHES

The unit contains two configurable over-temperature limit controls, positioned behind the unit's
front panel, under the Edge Controller:
•
Automatic Reset: If the unit's operating temperature exceeds the limit set on the switch,
the unit goes into an alarm mode and shuts the unit down. When the temperature falls
10 degrees below the limit, the unit automatically resumes operation without operator
intervention. The limit range is manually adjustable from 32°F to 200°F (0°C to 93°C).
The default value is 190°F (88°C).
•
Manual Reset: If the unit's operating temperature exceeds the limit set on the switch,
the switch goes into an alarm mode and shuts the unit down. The unit cannot be
restarted until the switch is reset manually. The limit is preset to 210°F (98.9°C) and
should not be changed.
Note the following points:
•
Both switches display the temperature to which the switch is set (the temperature limit),
not the actual temperature it is reading.
•
Both switches can display temperatures in Fahrenheit or Celsius.
•
The Auto-Reset switch is preset to 190ºF (88°C) but can be adjusted as needed to suite
local conditions, as described below.
AUTO-RESET
SWITCH
Figure 4-11: Over-Temperature Limit Switches

4.7.1 Adjusting the Automatic Reset Limit Switch Temperature

Perform the following steps to adjust the Automatic Reset Limit Switch temperature setting.
Temperature Adjustment Instructions
1. Power the unit ON and remove the front panel to expose the Over-Temperature Limit
switches.
2. Press the Automatic Reset Limit Switch's SET button: SP appears in the display.
3. Press the SET button again. The current setting stored in memory is displayed.
4. Press the ▲ or ▼ arrow buttons to change the display to the desired temperature setting.
5. When the desired temperature is displayed, press the SET button
6. Press both the SET and ▼ arrow buttons together at the same time. This step stores the
setting in memory; note that OUT1 appears in the upper-left corner of the display as
confirmation.
OMM-0137_E • GF-211 •
12/13/2019
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
MANUAL RESET
SWITCH
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