AERCO Control System (ACS) - Manual (Page 19)

MC2: 04/23/13 Page 19 of 144
GF-131
AERCO Control System (ACS)
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288
Installation, Operation, and Maintenance Manual
OMM-0081_0D
2.5.1 Header Sensor Installation
A Header Sensor Kit, (part no. 122790) is provided with the ACS. This Kit contains the Header
Sensor (64038), a Thermowell (122758) and some heat conductive grease which MUST be
used with the Sensor. When installing the Sensor, use a 1/2 inch NPT tapped coupling or a 4 x
4 x 1/2 inch Tee fitting. Shielded pair, 18 AWG cable (Belden # 8760 or equiv.) is recommended
for Header Sensor wiring. The Header Sensor must be installed between 2 and 10 feet
downstream of the LAST boiler in the boiler plant’s supply water header. Install the Header
Sensor as shown below:
NOTE
The Header Sensor is a thermistor type sensor. The Resistance vs.
Temperature Chart for this sensor is provided in Appendix D. Length of
Header Sensor wire leads should not exceed 600 feet.
2.5.2 Return Sensor Installation
The Return Sensor is required to activate the Plant Delta Temperature function, as described in
section 3.9.14, on page 54.
As mentioned in paragraph 2.5, the Return Sensor is identical to the Header Sensor.
Therefore, if a Return Sensor is being installed, another Header Sensor Kit (part no. 122790) is
required. The Return Sensor should be installed in the boiler water return line within 3 feet of the
first boiler in the boiler plant’s return water line. The installation details shown in Figure 2-3 for
the Header Sensor also apply to the Return Sensor. If used, install the Return Sensor as shown
below:
Header Sensor Installation
1. Refer to Figure 2-3 for the Header Sensor installation details.
2. Install the Header Sensor and Thermowell into the 1/2 inch NPT tapped coupling or a 4 x
4 x 1/2 inch Tee fitting using heat-conductive grease provided. This will aid in its
response.
3. For proper response, ensure that the Header Sensor probe is inserted at least 2 inches
into the water flow.
4. Using shielded pair cable (Belden #8760 or equiv.) connect the Header Sensor leads to
HDR SEN terminals 4 and 5 on the ACS. There is no polarity to observe when making
these connections.
5. Terminate the cable shield at SHLD terminal 3 of the ACS. DO NOT terminate the shield
at the Sensor end of the cable.
Return Sensor Installation
1. Refer to Figure 2-3 and install the Return Sensor and Thermowell into the 1/2 inch
tapped coupling or or Tee fitting using heat conductive grease.
2. Using shielded pair cable (Belden #8760 or equiv.), connect Return Sensor leads to
terminals 6 and 5 on the ACS. There is no polarity to observe when making these
connections.
3. Terminate the cable shield at SHLD terminal 3 of the ACS. DO NOT terminate the
shield at the Sensor end of the cable.