Watts AERCO Benchmark 2.0, User Manual

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INSTALLATION
2-6
GND
NEU
L2
L1
220 VAC, 1 PHASE
220 VAC, 1 Phase
GND
NEU
L2
L3
L1
208 VAC, 3 PHASE
208 VAC, 3 Phase
GND
L2
L3
L1
460 VAC, 3 PHASE
460 VAC, 3 Phase
Figure 2.7
AC Terminal Block Configurations
2.6 MODE OF OPERATION and FIELD
CONTROL WIRING
The Benchmark Boiler is available in several
different modes of operation. While each unit is
factory configured and wired for a particular
mode, some field wiring may be required to
complete the installation. This wiring is typically
run to the Input/Output (I/O) Box located on the
front of the unit behind the removable front door
(see Fig. 2.8). A brief description of each mode
of operation, and their requirements, is de-
scribed in the following paragraphs. Additional
information concerning field wiring is provided in
paragraphs 2.7.1 through 2.7.9. For additional
information on modes of operation, refer to
Chapter 5.
LOWER RIGHT CORNER OF
FRONT PANEL
TERMINAL STRIPS
Figure 2.8
I/O Box Terminal Location
2.6.1 CONSTANT SETPOINT MODE
The Constant Setpoint Mode is used when it is
desired to have a fixed setpoint that does not
deviate. No wiring connections other than
electrical supply connections are required for
this mode. However, if desired, fault monitoring
or enable/disable interlock wiring can be utilized
(see paragraphs 2.7.9.1 and 2.7.10).
2.6.2 INDOOR/OUTDOOR RESET MODE
This mode of operation increases supply water
temperature as outdoor temperatures decrease.
An outside air temperature sensor (AERCO PN
GM-122791) is required. The sensor MUST BE
wired to the I/O Box wiring terminals (see Fig.
2.9). For more information concerning the
outside air sensor installation, refer to paragraph
2.7.1