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
113
of
157
7.3.4
Option 4 Outdoor Reset: Modbus Header Temp Sensor & Modbus Outdoor
Temp Sensor
OPTION 4
Instructions: Outdoor Reset, Modbus Header Temp Sensor & Modbus Outdoor
Temp 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.
St
ep 1: HEADER TEMP SENSOR WIRING
– ANY BOILER
Using the Modbus Transmitter provides gives the plant the ability to use the Backup
manager feature. This allows the any of the client units to become a Backup manager if
the manager unit is not communicating.
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
Header Temp Sensor
(P/N
61040
) to pins
2
and
3
of the
Modbus
Transmitter
, 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
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: 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