OMM-0153_E
• 5/11/2023 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 80 of 124
CENTURION Installation, Operation & Maintenance Manual
SECTION 8: WATER HEATER MANAGEMENT
Figure 8-10: Operating Controls: Lead/Lag Control Screen
8.7 WHM Hardware Installation & Set-Up Instructions
The following sections provide the basic installation and set-up instructions for implementing a
Water Heater Management System (WHM) to control up to 16 Centurion Water Heaters.
8.7.1 Installation Notes
Multi-unit configurations require a sequencing valve. Building automation system is available on-
board via Modbus TCP, BACnet MSTP and BACnet IP (go to
Main Menu
→
Advanced Setup
→
Comm & Network
→
BAS
).
If using ProtoNode SSD then you
must
adhere to the procedure below. Failure to complete
these steps can result in the failure of the WHM system.
a) Do
NOT
install the ProtoNode Device at the outset of the installation. If already installed,
you must physically disconnect it from the Modbus network in I/O board.
b) Make sure that the Modbus load and bias resistors are properly configured for the system
to operate without the ProtoNode installed.
c) Temporarily set the WHM system for Constant Setpoint mode of operation (see below).
d) Turn on and completely test the installation to verify that it is operating proper.
e) Once the installation is working properly as a WHM system, install the ProtoNode Device.
f) Make sure that the Modbus load and bias resistors are properly configured for the system
to operate with the ProtoNode installed.
g) Set the WHM system for desired mode of operation (Setpoint mode).
h) Test the system completely with the ProtoNode installed.
8.7.2 Hardware Installation
All Centurion Water Heaters that will be controlled by a WHM Manager must be equipped with
an actuator-controlled Sequencing Isolation Valve. If this valve is not already installed at the
outlet, complete the instructions in Section 2.13.
8.7.3 WHM Modbus Network Wiring
As previously mentioned, all units being controlled by the WHM will be connected to a RS485
Modbus Network. All Modbus networks are wired in a daisy-chain configuration using a
Manager/Client scenario as shown below.
