T7200D,E, T7300D,E,F AND Q7300 SERIES 2000 PROGRAMMABLE COMMERCIAL THERMOSTATS AND SUBBASES
63-4355—422
Fig. 19. Use of external relay and tran sformer for
auxiliary loads greater than 1.6A.
TROUBLESHOOTING GUIDE
Refer to Table 13 for troubleshooting information.
M4944
L1
(HOT) L2 1
1
2
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
RELAY REQUIRED (R8222 OR SIMILAR).
Q7300 SUBBASE
TO
LOAD
AUXILIARY
RELAY
CONTACTS
A1
A2
A3
Table 13. Troubleshooting Information.
Symptom Possible Cause Action
Display will not come on. Thermostat is not being powered. •Check that X terminal is connected to the system
transformer.
•Check for 24 Vac between X and R or RH terminals.
—If missing 24 Vac:
—check if the circuit breaker is tripped; if so, reset
the circuit breaker.
—check if the system fuse is blown; if so, replace
the fuse.
—check if the HVAC equipment power switch on
the is in the Off position; if so, set to the On
position.
—check wiring between thermostat and HVAC
equipment and replace any broken wires and
tighten any loose connections.
—If 24 Vac is present, proceed with troubleshooting.
Temperature display is
incorrect. Room temperature display has been
reconfigured. Enter Installer Setup number 37 and reconfigure the
display.
Thermostat is configured for °F or °C
display. Enter Installer Setup number 14 and reconfigure the
display.
Bad thermostat location. Relocate the thermostat.
Display shows two dashes and a degree
sign. Installer Setup 22 is set for remote sensing and the
sensor is missing or the circuit is open or shorted.
Temperature settings will
not change.
(Example: Cannot set
heating higher or cooling
lower.)
Upper or lower temperature limits were
reached. Check the temperature setpoints:
•Heating limits are 40 to 90°F (7 to 31°C)
•Cooling limits are 45 to 99°F (9 to 37°C)
The setpoint temperature range stops
were configured. Check Installer Setup number 34 and 35 and reconfigure
the setpoint stops.
Keypad is locked. When a locked key is
pressed, LOC flashes on the LCD. •Reset DIP switch 1 on back of thermostat to enable
keypad.
•Enter Installer Setup number 25 or 40 and reconfigure
keypad lockout level.
Unable to configure
Installer Setup Installer Setup is locked out. Reset the DIP switch 1 on back of thermostat to enable
keypad.