AERCO BMS II BOILER - Manual (Page 18)

INSTALLATION
2-6
PROBE DEPTH MUST
EXTEND AT LEAST 2"
INTO PIPE WELDED 1/2"
COUPLING OR
4"x4*x1/2"
T - FITTING
HEADER SENSOR
WITH THERMOWELL
INSTALLED
Figure 2-3. Header Sensor Installation Details
Outdoor Air Sensor
The Outdoor Air Temperature Sensor (part no. GP-122662) is required when operating in the BMS II in
the Outdoor Reset Mode (paragraph 4.2). An Outdoor Air Sensor Kit (part no. GM-122781) is also
available. This kit contains the Sensor (GP-122662) and a Mounting Bracket for wall mounting. The
Outdoor Air Sensor should be mounted on the North side of the building, shielded from direct sunlight,
and away from air intakes or outlets from the building. Shielded pair 18 AWG cable (Belden # 8760 or
equiv.) is recommended for sensor wiring. The Outdoor Air Sensor can be mounted up to 600 feet from
the BMS II.
NOTE
The Outdoor Air Sensor is a thermistor type sensor. The Resistance vs.
Temperature Chart for this type of sensor is provided in Appendix E. The
length of the Header Sensor wire leads should not exceed 600 feet.
1. Refer to Figure 2-4 for a typical Outdoor Air Sensor installation.
2. Attach the sensor to the mounting bracket and secure the bracket in a suitable location on the North
side of the building.
3. Using shielded pair cable (Belden #8760 or equiv.), connect the two Sensor leads to terminals 1 and
2 on the BMS II. There is no polarity to observe when connecting the sensor.