14
TERMINAL CONNECTIONS
The wall thermostat terminal block is located behind the front panel and is easily accessible on front of control
panel.
Fig. 24 – Terminal Connector and Status LED Location
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Improper wiring may damage unit electronics. Common
busing is not permitted. Damage or erratic operation may
result.
CAUTION
!
R
Y
GH
GL
C
W
O
Common
Energy
Management
(24VAC in)
TYPICAL WALL THERMOSTAT
TERMINAL BLOCK
See Note 1
See Note 2
NOTES
:
1. Use terminal “O” for heat pump connection only.
2. Terminal “C” (common) is typically only required for digital
thermostats.
TERMINAL
DESIGNATION
R
24 VAC
W
Electric Heat
Y
Compressor
O
Reversing Valve
GH
High Fan
GL
Low Fan
C
Common
NOTE
: Any illegal input combinations will be captured as thermostat wiring
failures and will light the STATUS LED indicator on main board
(see
Intelligent Self ---Checking Control
section)
Fig. 25 – Wiring Connections
ENERGY MANAGEMENT INPUT (FRONT DESK CONTROL)
The controller can handle a switch signal from remote energy management input, called EM signal or front desk
control. Input must be 24VAC. If system receives a 24VAC signal, it will turn unit off; otherwise, the unit runs in
connections.
INTELLIGENT SELF--CHECKING CONTROL
Your E-TAC has a computer board that continuously checks key components of the unit to ensure they are
operating properly. Under normal operation, unit status indicator (STATUS, on main PCB), light is steadily ON.
If there is a major problem, the unit will shut down and display a diagnostic failure code on the unit’s display. If
it is only a minor failure and unit is correcting the fault by itself, the diagnostic code will be flashed on the status
LED that can easily be seen when the front panel is removed (see Fig. 24). Failure STATUS codes are defined
in the table below
normal control. This function will be disabled under Freeze Guard protection. See Fig. 25 for terminal
STATUS LED
Wall Thermostat
Terminal Connections
Energy Management
Terminal Connections
Table 6—STATUS LED Indicator Definitions
1
2
3
4
5
6
7
8
High pressure protection (optional)
Indoor air temp sensor open/short
Indoor coil sensor open or short
Outdoor coil sensor open/short
Freeze Guard protection
Indoor coil freeze protection
Outdoor coil high temp protection
Defrost (heat pump type)
Indoor coil high temp protection
Thermostat wiring error
8-segment display ‘E1’, (the highest display grade)
8-segment display ‘F1’, with STATUS light flash 1 times and off 3 sec, repeat
8-segment display ‘F2’, with STATUS light flash 2 times and off 3 sec, repeat
8-segment display ‘F4’, with STATUS light flash 3 times and off 3 sec, repeat
8-segment display ‘FP’
STATU light flash 5 times and off 3 sec, repeat
STATU light flash 6 times and off 3 sec, repeat
STATU light flash 7 times and off 3 sec, repeat
STATU light flash 8 times and off 3 sec, repeat
STATU light flash 9 times and off 3 sec, repeat
9
10
NOTE: When status light is flashing, it will be ON for 1 seconds and OFF for another 1 seconds.
