TZ-4 TOTALZONEĀ® ZONE CONTROL PANEL
5 68-0259-1
Wiring Diagrams (Fig. 3 and 4)

Conventional Thermostats

Conventional (RWYG) thermostats can be used to control
conventional, multi-stage, and heat pump equipment. If the
thermostat has a common terminal, it is wired to C on the
panel, see Fig. 3. A multi-stage thermostat is wired with the
second and third stage of heat to W2 and W3 on the panel
thermostat connections, and with the second stage of cooling
to Y2. Leave the zone O/B thermostat jumper on the TZ-4
disconnected. See Single and Multi-Stage Operation in the
Operation section for instructions on staging the TZ-4.
The PC8900 with the W8900A or W8900C can be used as a
zone thermostat. See Fig. 4 for hookup. This thermostat can
be used to control up to 2 heat and 2 cool stages of
conventional equipment. When used to control heat pump
equipment, the W8900A is recommended.
Connect a jumper on the W8900 from Rc to Rh as shown in
Fig. 4. Wire terminals R and C to a transformer. If the system
current draw is within specifications, the R and C on the
W8900 could alternately be connected to R and C on the
TZ-4. The PC8900/W8900 draws 5 VA.
Fig. 3. Typical single-stage thermostat wiring.
M20509B
G
C
R
Y
W
COMMON (C) TERMINAL IS USED ONLY BY THERMOSTATS
THAT REQUIRE A COMMON WIRE.
MULI-STAGE THERMOSTATS ARE WIRED SIMILARLY BUT WITH
Y2 AND W2 USED FOR SECOND STAGE COOL AND HEAT.
THIRD STAGE OF HEAT (W3) CAN BE WIRED TO W3/AUX.
LEAVE O/B JUMPER ON TZ-4 DISCONNECTED.
TZ-4 THERMOSTAT
CONNECTORS
TYPICAL SINGLE STAGE
THERMOSTAT WIRING
1
2
3
1
3
2