Bst Implementation Instruction; Option 1 Constant Setpoint: Direct Wired Header Temp Sensor - Watts Aerco Benchmark BMK750 Operation And Service Manual

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 7 – BOILER SEQUENCING TECHNOLOGY

7.3 BST IMPLEMENTATION INSTRUCTION

There are 8 BST implementation options, described below. The instructions for each refer to I/O
board connections described in Section 2.11 in the Benchmark 750-6000 with Edge [i]: Install-
Startup Manual (OMM-0144, GF-217).
All instructions in the sections below refer to one or more of the following components:
•
Modbus Transmitter:
o P/N 24444-1 includes PT1000 Header Temp Sensor P/N 61058, box and power supply.
o P/N 24444-3 includes PT1000 Header Temp Sensor P/N 61058.
•
Header Temp Sensor, either:
o P/N 61040 (BALCO) if connecting directly to I/O board.
o P/N 61058 (PT1000) dual bead, if connecting to Modbus Transmitter
•
Outdoor Sensor, either:
o P/N 61047 (BALCO) if connecting directly to I/O board.
o P/N 61060 (PT1000) if connecting to Modbus Transmitter.

Option 1 Constant Setpoint: Direct Wired Header Temp Sensor

7.3.1
OPTION 1 Instructions: Constant Setpoint with Direct Wired Header Temp Sensor
HEADER TEMP SENSOR WIRING – BST MANAGER Unit
Step 1:
OPTION 1
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 in the I/O
Box.
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.
•
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.
OPTION 1 Step 2: CONNECT BOILERS IN DAISY CHAIN
1. Connect the boilers in a daisy chain, as shown below.
OMM-0145_D • GF-218 •
11/2/2020
HEADER TEMP SENSOR
Continued on next page
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