Option 7 Remote Setpoint: Modbus Header Sensor & 4-20Ma Setpoint Drive - Watts Aerco Benchmark Series Operation And Service Manual

Benchmark Platinum-Edge: Operation-Service Manual
SECTION 7 – BOILER SEQUENCING TECHNOLOGY
7.3.7 Option 7 Remote Setpoint: Modbus Header Sensor & 4-20ma
Setpoint Drive
OPTION 7 Instructions: Remote Setpoint, Modbus Header Sensor & 4-20ma Setpoint Drive
NOTE:
Both Header Sensor and 4-20ma Direct Drive must be wired. See the Edge Controller
Manual (OMM-0139, GF-213) for more information.
Step 1: HEADER SENSOR WIRING – ANY BOILER
MODBUS
1. Connect the Modbus Transmitter (P/N 65169) terminal Pin B to the I/O Board strip J3,
terminal 13 (BST RS485+) and Pin A to terminal 15 (BST RS485–) on any of the Boiler
units using Shielded pair 18 - 22 AWG cable.
2. Connect the shield to any Shield terminal, such as terminal 3 or 8 on strip J3.
2. Connect the Header Temperature Sensor (P/N 24410) to pins 2 and 3 of the Modbus
Transmitter units using Shielded pair 18 - 22 AWG cable.
3. Install a jumper wire between pins 1 and 2 of the Modbus Transmitter.
NOTES:
•
Polarity must be observed for the RS485 connections.
•
Ground the shield to any Shield terminal on the I/O Board (such as Terminal 3).
•
The Header 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.
•
There is no polarity to be observed. The ground for the shield is at the power supply
ground. The sensor end of the shield must be left free and ungrounded.
HEADER TEMP SENSOR
(P/N 24410)
Step 2: DIRECT WIRED 0-20mA OR 4-20mA WIRING – MANAGER
3. Connect the 4-20mA or 0-20mA terminals from the Direct Drive source to the I/O Board
strip J3, terminal 6 (Remote Analog In +) and terminal 7 (Remote Analog In –) on the
Manager.
4. Connect the shield to any Shield terminal on the I/O Board, such as terminal 3 or 8.
NOTES:
•
Shielded pair 18 - 22 AWG cable is recommended for this connection. Polarity must be
observed.
•
The ground for the shield is at the driver signal source.
Remote Signal +
Remote Signal –
OMM-0137_D • GF-211 • 7/16/2019
MODBUS TRANSMITTER
6 Remote Analog In +
7 Remote Analog In –
8 Shield
I/O BOARD STRIP J3
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
3 Shield
13 BST RS485+
15 BST RS485–
I/O BOARD STRIP J3
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