Watts CEN2000 User manual

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TAG-0104_A • 4/18/2023
Disclaimer
The information contained in this manual is subject to change without notice
from PVI Industries, LLC. PVI makes no warranty of any kind with respect to this
material, including, but not limited to, implied warranties of merchantability and
fitness for a particular application. PVI is not liable for errors appearing in this
manual, not for incidental or consequential damages occurring in connection
with the furnishing, performance, or use of these materials.
© 2023 PVI, a Watts Brand

Centurion Pre-Installation Electrical Power Guide
TAG-0104_A •4/18/2023 • [phone] • Mon-Fri, 8 am - 5 pm EST Page 2 of 6
1. GENERAL
Centurion natural gas fueled modulating and condensing water heaters are fully factory wired
packaged units which require simple external power wiring as part of the installation (Figure 2-
1). This technical guide is intended to help designers provide electrical power wiring (line
voltage) to Centurion units. Control wiring details are provided in other publications, depending
upon unit application. This document is intended only as a guide and therefore cannot include
all possible alternatives or unit applications. To comply with all codes and authorities having
jurisdiction, designers and installers must plan the electrical wiring carefully and execute the
installation completely. Emergency shutoffs, fusible fire switches, break glass stations, and
other electrical requirements should be considered and installed whenever necessary.
2. HEATER ELECTRICAL REQUIREMENTS
Centurion water heaters are available with the following power options:
Model
Voltage
Phase
MOCP
Amperage
CEN2000
208 V
3/ 60 Hz
20
460 V
3/ 60 Hz
15
Voltages lower than those specified in the table above will result in increased wear and
premature failure of the blower motor. Wire size and type should be made per the National
Electrical Code based on length and load.
The power box for field wiring connections is located in the upper right corner behind the unit
front panel. All copper wire must be connected to the power box.

Centurion Pre-Installation Electrical Power Guide
TAG-0104_A •4/18/2023 • [phone] • Mon-Fri, 8 am - 5 pm EST Page 3 of 6
Figure 2-1: Service Disconnect Switch Typical Location
Figure 2-2: Electrical Power Panel Internal Components
Service Disconnect
Switch
24 VDC POWER
SUPPLY
12V POWER
SUPPLY
TRANSFORMER
POWER
BREAKER
FUSE BLOCKS
TERMINAL
BLOCKS

Centurion Pre-Installation Electrical Power Guide
TAG-0104_A •4/18/2023 • [phone] • Mon-Fri, 8 am - 5 pm EST Page 4 of 6
3. PROVISIONS FOR SERVICE
Designers must provide emergency shutoffs and other devices to satisfy electrical codes. It is
also recommended to provide an electrical shutoff disconnect switch of suitable load carrying
characteristics on or near each Centurion water heater.
•No electrical boxes or field components should be mounted to the surface of the unit or
where they might interfere with the removal of the side or top panels for maintenance.
•The service disconnect switch should be mounted near the unit (Figure 2-1).
•Wiring conduit, EMT, or other wiring paths should be supported externally, not secured
to the unit.
•Electricians should be instructed as to where the wiring conduit should be located, such
as away from the relief valve discharge, drains, etc.
•All electrical conduit and hardware should be installed so that it does not interfere with
the removal of any covers, inhibit service or maintenance, or prevent access between
the unit and walls or another unit.
4. WATER HEATER WIRING
A dedicated protected circuit should be provided from the power source to the water heater. No
other electrical devices should be permanently wired on the same circuit. The protected circuit
and circuit breaker switch must be sized for the amperage values below.
An emergency switch (electrical shutoff) must be wired in series with power to the unit.
Connecting an emergency shutoff switch (E-stop) to the main power terminals of the water
heater is the recommended and safest way to totally disable and un-power the unit. Use of the
remote interlock, located on the I/O board, is not recommended since it does not cutoff power
within the unit, it only disables it. Under no circumstance should the remote interlock of the
WHM Manager unit be used as an emergency switch for the plant.
Figure 4-1 –Water Heater Wiring Diagram
The following table lists the input power requirements for all Centurion water heaters, including
the diagram number of each model’s corresponding schematic diagram:
Diag.
Voltage/Phase/Frequency
MOCP
Wires
1
208V / 3/ 60 Hz
20 A
5
2
460V / 3/ 60 Hz
15 A
4

Centurion Pre-Installation Electrical Power Guide
TAG-0104_A •4/18/2023 • [phone] • Mon-Fri, 8 am - 5 pm EST Page 5 of 6
For applicable wiring connections, refer to the schematic diagrams below.
Figure 4-2 –CEN2000: 208 V / 3/ 60 Hz - 5 Wire
Figure 4-3 - CEN2000: 460 V / 3
 / 60 Hz - 4 Wire –DOMESTIC
5. MULTIPLE UNIT WIRING
Whenever multiple units are installed within the same mechanical spaces, electrical code
requirements call for a single electrical shutoff for emergency use. It is the responsibility of the
electrical designer to comply with local codes and regulations affecting an individual installation.
208 V / 3/ 60 Hz
460 V / 3/ 60 Hz

Centurion Pre-Installation Electrical Power Guide
TAG-0104_A •4/18/2023 • [phone] • Mon-Fri, 8 am - 5 pm EST Page 6 of 6
Change Log
Date
Description
Changed by
4/18/23
Initial Release
DW Barron
© Watts Heating and Hot Water Solutions, LLC, 2023