Carrier Performance 52ME-U07-3, Installation And Operating Instructions Manual

Page: 15 / 24

15
TERMINAL CONNECTIONS
The wall thermostat terminal block is located behind the front panel and is easily accessible on front of control
panel.
STATUS LED
Wall Thermostat
Terminal Connections
Energy Management
Terminal Connections
A07088
Fig. 25 – 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.
A07076
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. 26 – 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
normal control. This function will be disabled under Freeze Guard protection. See Fig. 25 and Fig. 26 for
terminal connections.
INTELLIGENT SELF--CHECKING CONTROL
Your Carrier PTAC 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. 25). Failure STATUS codes are defined in
the table below
Table 6—STATUS LED Indicator Definitions
1 Indoor air temp sensor open/short 7---segment display ‘F1’, with STATUS light flash 1 time,off 2 seconds
2
Indoor coil sensor open/short 7---segment display
‘F2’, with STATUS light flash 2 time,off 2 seconds
3 Outdoor coil sensor open/short 7---segment display ‘F4’, with STATUS light flash 4 t ime,off 2 seconds
4 Freeze Guard protection 7---segment display ‘FP’
5
Thermostat wiring error
STATUS light flash 9 times and off 3 sec, repeat
6 Indoor coil high temp protection STATUS light flash 8 times and off 3 sec, repeat
7 Defrost (heat pump type) STATUS light flash 7 times and off 3 sec, repeat
8 Outdoor coil high temp protection STATUS light flash 6 times and off 3 sec, repeat
9
Indoor coil freeze protection
STATUS light flash 5 times and off 3 sec, repeat
NOTE : When status light is flashing, it will be ON for 0.5 seconds and OFF for another 0.5 seconds.