Benchmark 2500 - 3000 Boilers
CHAPTER 9. BOILER SEQUENCING TECHNOLOGY
Page
126
of
207
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0094_0F
09/30/2015
Ph.: 800-526-0288
GF-137
9.3.3 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 (P/N
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 (0.61 and 3.1m) 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.
Step 2 - Direct Wired Outdoor Sensor
1. On the MASTER Unit, Connect the Outdoor Temperature Sensor (P/N
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 (61m) from the
boiler.
Temp Sensor PN 123525
Temp Sensor PN 61040
Header Temp Sensor
I/O Box
