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
118
of
157
7.3.6
Option 6 Remote Setpoint: Direct Wired Header Temp Sensor & Modbus
Setpoint Drive
OPTION 6
Instructions: Remote Setpoint, Direct Wired Header Temp Sensor, Modbus Setpoint
Drive
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.
Step 1: 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.
3. Connect the
Header Temp Sensor
to pins
2
and
3
of the
Modbus Transmitter
using
Shielded pair 18 - 22 AWG cable.
4. On the
Modbus Transmitter
, install a jumper wire between pins 1 and 2.
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 or 8).
•
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: OUTDOOR SENSOR WIRING
1. If you have not already done so, complete step 1 of the instructions above to connect the
Modbus Transmitter
to the I/O Board.
2. Connect the
Outdoor Temp Sensor
to
Pins 5
and
6
of the
Modbus Transmitter
using a
shielded pair 18 - 22 AWG cable.
3. On the
Modbus Transmitter
, install a jumper wire between
Pins 4
and
5
.
MODBUS TRANSMITTER
HEADER TEMP SENSOR
I/O BOARD
MODBUS TRANSMITTER
OUTDOOR TEMP SENSOR
I/O BOARD