Watts AERCO Benchmark OMM-0136 - Page 96

Benchmark Platinum-Edge [II]: Operation-Service Manual
SECTION 7 – BOILER SEQUENCING TECHNOLOGY
OMM-0137_E • GF-211 • 12/13/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 96 of 153
OPTION 4 Instructions: Outdoor Reset, Modbus Header Temp Sensor & Modbus Outdoor
Temp Sensor
NOTES:
• Polarity must be observed for the RS485 connections. The ground for the shield is at
the Shield terminal on the I/O the board.
• The Outdoor Temp Sensor must be mounted 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 Temp 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
On All Boiler:
1. Go to: Main Menu → Advanced Setup → BST Cascade → Cascade Configuration:
• Set the Unit Mode parameter to BST Client.
2. Go to: Main Menu → Advanced Setup → BST Cascade → Cascade Communication:
• Set the Unit Address parameter to the communication address of the unit.
On the BST Manager only:
1. Go to Main Menu → Advanced Setup → BST Cascade, set the Parameters to the Values
in each menu in the table below.
Menu/Screen Name
Parameters
Values
Cascade
Configuration
Unit Mode
BST Manager
Hdr Temp Sensor
Network
Sensor Comm Address
240
Hdr Temp Point
14
Application
Configuration
Application
Space Heating
SH Operating Mode
Outdoor Reset
Outdoor Temp Sensor
Outdoor Sensor
Sensor Comm Address
240
Outdoor Temp Point
15
Plant Setpoint
Header temperature required for the cascade
Cascade
Communication
Min Address
The minimum unit address in the cascade
Max Address
The maximum unit address in the cascade
Cascade Baud Rate
The baud rate for the cascade.
15 BST RS485–
13 BST RS485+
3 Shield
MODBUS TRANSMITTER
OUTDOOR TEMP SENSOR
(P/N 61048)
I/O BOARD STRIP J3