Option 3 - Outdoor Reset With Direct Wired Header Sensor And Direct Wired Outdoor Sensor - Aerco BENCHMARK 2500DF User Manual

CHAPTER 10. BOILER SEQUENCING TECHNOLOGY
10.3.3 Option 3 - Outdoor Reset with DIRECT WIRED Header Sensor AND DIRECT
WIRED Outdoor Sensor
NOTE: Both Header Sensor AND Outdoor Sensor must be wired. See the C-More Controller User
Manual, OMM-0032, GF-112 and ProtoNode User Manual, OMM-0080, GF-129 for more information.
Step 1 - Direct Wired Header Sensor Wiring
1. On the MASTER Unit, connect the Header Temperature Sensor (AERCO PN 61040) to the Feed
Forward (FFWD) terminals on the P-1 Harness Via the terminal block labeled "Header Temp sensor"
in the I/O Box.
NOTES: The header sensor must be installed between 2 and 10 feet downstream of the LAST boiler in
the plant's supply water header. Shielded pair 18 - 22 AWG cable is recommended for header sensor
wiring. There is no polarity to be observed. The ground for the shield is at the "SHLD" terminal in the I/O
the Box. The sensor end of the shield must be left free and ungrounded.
Temp Sensor PN 61040
Step 2 - Direct Wired Outdoor Sensor
1. On the MASTER Unit, Connect the Outdoor Temperature Sensor (AERCO PN 123525) to the "OUT"
and "COM" terminals in the I/O Box.
NOTES:
• Twisted shielded pair 18 - 22 AWG cable is recommended for header sensor wiring. There is no
polarity to be observed. The ground for the shield is at the "SHLD" terminal in the I/O the Box. The
sensor end of the shield must be left free and ungrounded.
• When mounting the Outdoor sensor, it must be located on the North side of the building where an
average outside air temperature is expected. The sensor must be shielded from direct sunlight as well
as impingement by the elements. The outdoor sensor may be wired up to 200 feet from the boiler.
OMM-0099_0A
GF-145
Benchmark 2500DF-3000DF
Temp Sensor PN 123525
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
Page 129 of 234
PR1: 05/21/2014