Part number 550-142-085/0712
WM97+
gas
-
fired
water
boiler
—
Boiler Manual
– 64 –
Figure 72
WM97+
low voltage
input and output
connections (24 VAC)
Thermostats
—
DO NOT
supply 24-volt
power to the thermostat circuits (H, J and
K in Figure 72) or attempt to supply 24 volts
for any other application.
DO NOT
connect any device to ZONE1 if
using
CWH
unit. This circuit is dedicated
to the water heater.
For thermostats that require a continuous
24-volt power source, connect the ther-
mostat power input to the “R-C 24 VAC”
terminal of the lower voltage terminal strip.
Zone valves
— If using 3-wire zone valves,
use relays to provide dry contacts to the
WM97+ control thermostat connections.
The zone valve end switches of 3-wire valves
carry 24 VAC from the valve.
Thermostat anticipator setting
—
0.1 amps.
WM97+ control factory default settings:
DHW heating is configured for direct pip-
ing to the bottom of the boiler. The DHW
circulator is powered from Zone 1 on a
call from the DHW aquastat (connected to
Zone 1 input). With this set-up, the boiler
circulator is NOT activated during DHW
heating. Zone 2 and Zone 3 are also NOT
activated during domestic priority heating
on Zone 1.
The factory default for space heating is de-
signed for finned-tube baseboard, and set
up to activate Zone 2 and Zone 3 on a call
for heat from the zone thermostats.
See instructions on the following pages
to adjust the WM97+ control settings to
match installation requirements.
Field wiring
(continued)
Low voltage wiring (24 VAC)
Make the following low-voltage connections, some of which depend
on your system and how the WM97+ control will be programmed.
The callouts below refer to Figure 72.
H
Zone 1 call for heat (space heating or DHW circuit)
1. The WM97+ control provides inputs 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. If operating on space heating only, the
Zone 1 output can be used as described for Zone 2.
2. Control options require that DHW tanks be controlled from Zone 1
if domestic water priority is required.
3. ALWAYS connect DHW aquastat to Zone 1 input 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 the system.
J
Zone 2 call for heat (space heating)
1. Use the Zone 2 input to:
a. Connect the thermostat for a space heating zone.
b. Connect end switch wire(s) (must be ISOLATED contacts) to
start boiler on a call for space heating.
c. Connect system control input for space heating call for heat
(ISOLATED contact only).
2. The WM97+ control will activate the 120-VAC Zone 2 output if
the Zone 2 thermostat or input device calls for heat, after DHW
heating is satisfied.
K
Zone 3 call for heat (space heating)
1. Same as Zone 2. Zone 3 is not used for zone valve systems.
M
Outdoor temperature sensor (for outdoor reset)
1. The WM97+ control provides programmable options if using an
outdoor temperature sensor. This sensor is supplied with the boiler.
The outdoor sensor must be installed unless specifically
exempted in the Energy Act statement on page 129.
2. Mount the outdoor sensor on an exterior wall, shielded from direct
sunlight or flow of heat or cooling from other sources. The wire out-
let on the sensor must be oriented DOWN to prevent water entry.
3. Connect the sensor leads to the ODT TEMP terminals, as shown
in the wiring diagrams. Thermostat wire can be used to connect
the sensor.
N
External limits (will cause manual reset when opened)
1. Connect isolated contacts of external limits across the MAN LIMIT
terminals to cause the WM97+ control to lock out (requiring
manual reset) if the limit opens. The limit must close and the con-
trol must be re-started using the procedure given in this manual.
P
External limits (will cause automatic reset if opened)
1. Connect isolated contacts of external limits across the AUTO LIM-
IT terminals to cause the WM97+ control to shut down the boiler
on limit opening, then automatically restart after the limit closes.
R
Alarm terminals
1. The alarm contacts will close if the WM97+ control enters lockout.
Contacts will remain closed until the WM97+ control is reset.
2. Alarm contacts are isolated and are rated 1 amp at 24 VAC.
Содержание WM97+110
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