TZ-3 TOTALZONE® ZONE CONTROL PANEL
68-0223-2
12
Rebooting Microprocessor
Certain conditions can hang up the microprocessor. To reset
it, press and release the Boot button. The system reboots and
enters the Purge mode.
Discharge Air Temperature Sensor
The Discharge Air Temperature Sensor (not included) is a
supply-duct-mounted temperature probe used to control
capacity and prevent over-heating or coil-icing. The sensor
attaches to the TL terminals on the panel.
Set the high limit temperature on the maximum temperature
dial on the panel, located left of the stage timer. See. Fig. 19.
Set the temperature from 110 °F to 160°F in ten-degree
increments. The recommended setting for fossil fuel/ electric
systems is 160°F (default factory setting). For heat pump
systems, the recommended setting is 120F.
The cooling temperature limit can be set at 40°F or 48°F.
Fig. 19. Maximum temperature dial.
IMPORTANT
Be sure the Discharge Air Temperature Sensor wir-
ing does not run parallel with line voltage wiring
unless more than 12 in. of separation exists or
shielded cable is used.
Use DIP switch 2 to change cooling limit settings.
If the system trips due to exceeding a high or low temperature
limit, the heating or cooling system shuts down and the fan
continues running to purge the conditioned air from the
plenum.
When the low limit is tripped, the Cool LED flashes until it
resets. When the high limit is tripped, the Heat LED flashes
until it resets.
Once the temperature recovers by ten degrees, the
equipment run resumes.
Zone-A-Lone Switch
When the Zone-A-Lone switch is in the occupied position and
the OC/OC terminals are not used, the system functions as a
normal zone control system. When switched to the
unoccupied position, all dampers are opened and all requests
for heat, cool, or fan, except from zone one, are not honored.
The zone one thermostat becomes the controlling thermostat
for the entire system. During long unoccupied periods, one
thermostat can be set back instead of adjusting each zone
thermostat in the building.
The T8601D2027 and T8611G2051 include two OC terminals.
When wired to the TZ-3 OC terminals, and with the Zone-A-
Lone switch in the occupied position, the board enters the
unoccupied mode during the Leave and Sleep programs. This
feature requires two extra wires to the Zone 1 thermostat.
Circuit Breaker Protection
A built-in thermal circuit breaker protects the TotalZone panel.
This circuit breaker protects the panel against shorts in the
thermostat and damper wiring and the remote occupied/
unoccupied switch. It does not protect against shorts in the
wiring of the HVAC equipment into the panel.
When the circuit breaker is tripped, none of the LEDs
illuminate and the yellow rectangular component located to
the left of the TR1 and TR2 terminals is hot to the touch.
Remove power to the panel for at least ten seconds to allow
the circuit breaker to cool off and reset. To eliminate the short,
verify the dampers and thermostat wiring.
Fan On In Heat
The system blower can be set to come on with a call for heat
as required for hydro-air, heat pump, or electric heat systems.
Set the blower using DIP switch 8.
TotalZone Add-A-Zone Panels
Using TotalZone Add-A-Zone Panels, the system can be
expanded to up to 30 zones. There are three models: TAZ-1,
one zone; TAZ-2, two zone; and TAZ-3, three zone. Two wires
are required to connect the TAZ to the TZ-3.
IMPORTANT:
When multiple panels are used, it is important that
the transformers be in-phase. Check the phasing by
measuring for 24V across the TR2 transformer termi-
nals on each panel. There should be 0 Vac. If not,
reverse the TR1and TR2 transformer wires on one of
the panels and recheck.
See Fig. 13 and the TAZ installation instructions for more
information.
Dip Switch
Status
Cooling
Temperature
Limit
2
Off
40°F
2
On
48°F
130 F
MAXIMUM
TEMPERATURE
M19079
120 F
110 F
140 F
150 F
160 F
DIP Switch 8
Fan Control
Off
HVAC system
On
Fan on in heat
