AERCO BMK 1.5 LN July 2011 - Manual (Page 52)

CHAPTER 4: INITIAL START-UP
Page 52 of 152 PR2: 05/09/12
Benchmark 1.5LN Low NOx Boiler
Operation and Maintenance Manual
OMM-0041_0D
GF-120
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
2. Disconnect AC power from the unit.
3. Shut off the gas supply to the unit.
4. Remove the manometer and barbed fittings and reinstall the NPT plug using a suitable
pipe thread compound.
5. Remove the combustion analyzer probe from the vent hole. Replace the NPT plug in
the vent hole using a suitable pipe joint compound.
6. Replace the unit’s side panels and front door.
4.6 OVER-TEMPERATURE LIMIT SWITCHES
The unit contains both automatic and manual reset over-temperature limit switches. These
switches are mounted on a plate as shown in Figure 4-6. The switches can be accessed by
opening the front panel door of the unit. The manual reset switch is not adjustable and is
permanently fixed at 200°F. This switch will shut down and lock out the boiler if the water
temperature exceeds 200°F. Following an over-temperature condition, it must be manually reset
by pressing the RESET button before the boiler can be restarted. The automatic reset over-
temperature switch is adjustable and allows the boiler to restart, once the temperature drops
below its temperature setting. Set the automatic over-temperature switch to the desired setting.
FRONT VIEW
ADJUSTABLE
TEMPERATURE
LIMIT SWITCH
RESET BUTTON
FOR MANUAL
TEMPERATURE
LIMIT SWITCH
SEE
DETAIL “A”
DETAIL “A”
Figure 4-6 Over-Temperature Limit Switch Locations