Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 7
– BOILER SEQUENCING TECHNOLOGY
OMM-0145_A99
• GF-218 • 9/18/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page
120
of
157
7.3.7
Option 7 Remote Setpoint: Modbus Header Temp Sensor & 4-20ma
Setpoint Drive
OPTION 7
Instructions: Remote Setpoint, Modbus Header Temp Sensor & 4-20ma Setpoint
Drive
NOTE:
Both
Header Temp Sensor
and
4-20ma Direct Drive
must be wired. See the
Edge [i]
Controller Manual
(OMM-0141, GF-213-B) for more information.
Step 1:
MODBUS
HEADER TEMP SENSOR WIRING
– ANY BOILER
1. Connect the
Modbus Transmitter
terminal
Pin B
to the
RS485+
terminal, and
Pin A
to
the
RS485-
terminal on the I/O Board of any Boiler unit, using shielded pair 18 - 22 AWG
cable.
2. Connect the shield to any
SHLD
terminal on the I/O Board.
2. Connect the
Header Temp Sensor
to pins
2
and
3
of the
Modbus Transmitter
units using
Shielded pair 18 - 22 AWG cable.
3. On the
Modbus Transmitter
, install a jumper wire between pins 1 and 2.
NOTES:
•
Polarity must be observed for the RS485 connections.
•
Connect the shield to any
SHLD
terminal on the I/O Board.
•
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.
•
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.
Step 2: DIRECT WIRED 0-20mA or 4-20mA WIRING
– BST MANAGER
1. Connect the
4-20mA
or
0-20mA
terminals from the Direct Drive source to the
Ain+
and
Ain-
terminals on the BST Manager.
2. Connect the shield to any
SHLD
terminal on the I/O Board.
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.
MODBUS TRANSMITTER
HEADER TEMP SENSOR
I/O BOARD
I/O BOARD