Weil-McLain WM97+70 Manual page 63

WM97+ -
gas fired water boiler
Field wiring
Line voltage wiring (120 VAC)
Make the following line-voltage connections, some of which depend
on your system and how the WM97+ control will be programmed.
The callouts below refer to Figure 71.
A
120-VAC Power input
1. Provide and install a fused disconnect or service switch (15-ampere
rated recommended) as required by applicable codes.
2. Connect minimum
15-ampere, 120 VAC
boiler line voltage terminal strip as shown in Figure 71.
3. If possible, provide a surge suppressor in the supply power line.
This will reduce the possibilities of WM97+ control damage due
to line surges.
B
Ground wire connection terminal block
1. Ground wires must be terminated with
terminals.
2. Connect ground wires to the grounding block, item
C
Zone 1 output (CIRC1), 120 VAC (DHW circuit, if DHW
used)
1. The WM97+ control provides 120-VAC outputs for up to three
zones.
The WM97+ control default setting is for three space
heating zones. The control settings must be changed to
operate on DHW.
2. Control options require that DHW tanks be controlled from Zone 1
if domestic water priority is required.
3. ALWAYS connect the DHW circulator to Zone 1 if domestic prior-
ity is required. This can be done if the DHW tank is piped to the
DHW connections out the bottom of the WM97+ or if the DHW
tank is piped as a separate zone in a circulator-zoned system.
4. Zone 1 can be used to provide 120 VAC to a zone circulator if
DHW is not used.
D
Zone 2 output (CIRC2), 120 VAC
1. Use the Zone 2 output to:
a. Provide 120 VAC to a system circulator (such as on a zone valve
system with system circulator).
b. Provide 120 VAC to a zone circulator.
c. Provide 120 VAC to a relay coil, with the relay contact used to
enable/disable another device.
2. The WM97+ control will activate Zone 2 if the Zone 2 thermo-
stat or input device calls for heat, after DHW heating (if used) is
satisfied.
E
Zone 3 output (CIRC3), 120 VAC
1. Same as Zone 2. This output is not used for zone valve systems.
Activating system zoning controls
1. To activate system controls (zoning panels, building management
controls, etc.):
a. Use the output from Zone 1 to directly control the DHW
circulator. Connect the Zone 2 output to an isolation relay.
b. Use the relay contact to enable/disable the system space heat-
ing controls.
c. This allows the WM97+ control to provide domestic prior-
ity and outdoor reset control of supply water temperature to
maximize boiler efficiency.
Part number 550-142-085/0712
— Boiler Manual
(continued)
power wiring to WM97+
female spade
¼-inch
.
B
WM97+
Figure 71 line voltage
connections (120 VAC)
CWH applications, if installed
and ZONE1 circuits are dedicated to the
Weil-McLain Companion Water Heater
and cannot be used for other purposes.
See CWH manual for details
Output circuits are 120 VAC. If an out-
put is to operate a low voltage circuit,
use an isolation relay.
CIRCULATOR POWER
mum allowable current for each
circulator is 2.2 amps at 120 VAC
For circulators with higher amp rat-
ings, you must install a circulator relay
or starter to provide line voltage to the
circulator. For circulators rated over 2.2
amps, connect only the circulator relay
or starter coil to the WM97+ circulator
terminals.
WIRING INFORMATION
ure 70, page 62 for wiring connection
locations. See Figure 73, page 65 for the
complete schematic wiring diagram. See
Figure 74, page 66 for the complete ladder
wiring diagram.
input and output
— CIRC1
—
The maxi-
.
— See Fig-
– 63 –