24
UNIT
HIGH VOLTAGE
WIRING
UNIT PUMP
HIGH VOLTAGE
WIRING
Fig. 27: Wiring Locations
Wiring the Enable/Disable
Connect the Enable/Disable (terminals 11, 12) wir-
ing to the field wiring terminals (shown in Fig. 29).
Alternately, any dry contact closure (including a
remote thermostat) across these terminals will enable
the XTherm unit to run. Caution should be used to
ensure neither of the terminals becomes connected
to ground.
Wiring the System Sensor
The System Sensor (S3) is required for all selectable
modes unless the units firing rate will be controlled by
an external source, such as our TempTracker MOD+
Hybrid sequencer. Proper placement and method of
installation are critical for proper operation of the sys-
tem. See Section “Applications & Modes.”
1. There is no connection required if using an exter-
nal sequencer for firing rate control.
Field Wiring Connection
CAUTION:
Label all wires prior to disconnection
when servicing controls. Wiring errors can cause
im-proper and dangerous operation. Verify proper
operation after servicing.
DANGER: SHOCK HAZARD
Make sure electrical power to the heater is dis-
con-nected to avoid potential serious injury or damage
to components.
2. If using an Outdoor Sensor (option B-32), con-
nect the sensor wires to the terminals marked
OUTDOOR SENSOR (see Fig. 29). Caution
should be used to ensure neither of these termi-
nals becomes connected to ground.
3. Use a minimum 18 AWG wire for runs of up to 150
feet.
4. Mount the outdoor sensor on an exterior surface
of the building, preferably on the north side in an
area that will not be affected by direct sunlight and
that will be exposed to varying weather conditions.
Fig. 28: Locator Dimples for Low Voltage Wiring
2. Where using a System Sensor (S3), connect the
sensor wires to the terminals marked SYSTEM
SENSOR (See Fig. 29).
3. Use a minimum of 18 AWG wire for runs up to 150
feet.
4. Install the system sensor in a drywell (option
B-31) within 5 feet downstream of the de-coupler
(hydronic system), OR into the volume of the buf-
fer tank when used (hydronic system), OR into the
volume of the water storage tank (domestic hot
water system).
Wiring the Outdoor Sensor
1. There is no connection required if an outdoor sen-
sor is not used in this installation.