Watts AERCO Benchmark BMK750 Operation And Service Manual page 114

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 7 – BOILER SEQUENCING TECHNOLOGY
OPTION 4 Instructions: Outdoor Reset, Modbus Header Temp Sensor & Modbus Outdoor
Temp Sensor
OUTDOOR TEMP SENSOR
NOTES:
•
Polarity must be observed for the RS485 connections.
•
Ground the shield at any SHLD terminal in the I/O the Board.
•
When mounting the Outdoor sensor, it must be located on the North side of the building
where an average outside air temperature is expected. The sensor must be shielded
from direct sunlight as well as impingement by the elements. The outdoor sensor may
be wired up to 200 feet (61m) from the boiler.
•
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 3 – OPTION 4 CONFIGURATION
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.
On All Boiler:
Main Menu → Advanced Setup → BST Cascade → Cascade
1. Go to:
•
Set the Unit Mode parameter to BST Client.
Main Menu → Advanced Setup → BST Cascade → Application
2. Go to:
•
Set the Unit Address parameter to the communication address of the unit.
On the BST Manager only:
Main Menu → Advanced Setup → BST
1. Go to
in each menu in the table below.
Menu/Screen Name
Cascade
Configuration
Application
Configuration
OMM-0145_A99 • GF-218 •
MODBUS TRANSMITTER
Parameters
Auto Manager Transfer
Auto failover Type
Backup Manager Address
Unit Mode
Hdr Temp Sensor
Sensor Comm Address
Hdr Temp Point
Application
SH Operating Mode
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
9/18/2019
Cascade, set the Parameters to the Values
Values
Enabled (This is available on the Manger unit
only)
C-More
Enter the designated backup unit address
BST Manager
Network
240
14
Space Heating
Outdoor Reset
I/O BOARD
Configuration:
Configuration:
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