Option 3 Outdoor Reset: Direct Wired Header Temp Sensor & Direct Wired Outdoor Sensor - Watts Aerco Benchmark BMK750 Operation And Service Manual

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 7 – BOILER SEQUENCING TECHNOLOGY
Option 3 Outdoor Reset: Direct Wired Header Temp Sensor & Direct Wired
7.3.3
Outdoor Sensor
OPTION 3 Instructions: Outdoor Reset, Direct Wired Header Temp Sensor & Outdoor Sensor
NOTE:
Both Header Temp Sensor and Outdoor Sensor must be wired. See the Edge [i] Controller
Manual (OMM-0141, GF-213-B) for more information.
OPTION 3 Step 1: DIRECT WIRED HEADER TEMP SENSOR WIRING – BST MANAGER Unit
1. On the BST Manager unit, connect the Header Temp Sensor to the Feed Forward (FFWD)
terminals on the P-1 Harness via the terminal block labeled Header Temp sensor on the
I/O Board.
2. Ground the shield to any SHLD terminal on the I/O Board.
NOTES:
•
The Header Temp Sensor must be installed between 2 and 10 feet (0.61 and 3.1m)
downstream of the last boiler in the plant's supply water header.
•
Shielded pair 18 - 22 AWG cable is recommended for Header Temp Sensor wiring.
There is no polarity to be observed. Ground the shield to the Shield terminal on the I/O
Board. The sensor end of the shield must be left free and ungrounded.
HEADER TEMP SENSOR
OPTION 3 Step 2: DIRECT WIRED OUTDOOR SENSOR WIRING – BST MANAGER Unit
1. On the BST Manager Unit, connect the Outdoor Temp Sensor to the OUT and COM
terminals on the I/O Board.
2. Connect the shield to any SHLD terminal on the I/O Board.
NOTES:
•
Twisted shielded pair 18 - 22 AWG cable is recommended for Header Temp Sensor
wiring. There is no polarity to be observed. 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.
OUTDOOR TEMP SENSOR
OMM-0145_D • GF-218 •
11/2/2020
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