24VNA6: Installation Instructions
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17
Fan Motor
The fan motor requires 5 wires connected to VFD for operation. These
wires are: DC BUS, GND, +15V DC, Vsp, FG. Note high voltage may
be present on ALL wires because they are not earth or chassis ground
referenced. Do not attempt to measure voltages while running. Fan
speed is monitored by VFD and PCM continuously. If fan faults occur
verify the fan blade rotates freely without obstruction. Ensure all
electrical connections are secure and wires are undamaged.
Status Codes
shows the status codes flashed by the amber status light. Most
system problems can be diagnosed by reading the status code as flashed
by the amber status light on the control board.
The codes are flashed by a series of short and long flashes of the status
light. The short flashes indicate the first digit in the status code,
followed by long flashes indicating the second digit of the error code.
The short flash is 0.25 seconds ON and the long flash is 1.0 second ON.
Time between flashes is 0.25 seconds. Time between short flash and first
long flash is 1.0 second. Time between code repeating is 2.5 seconds
with LED OFF.
Codes are easily read from user interface (UI) or the 5x7 LED display on
the PCM
EXAMPLE
:
3 short flashes followed by 2 long flashes indicates a 32 code.
shows this to be low pressure switch open.
Status Code Recall Mode
Active status codes are stored in memory even when power is absent.
The most recent flashing status code (highest priority active) can be
recalled from memory via Status Code Recall Mode is accessed by
shorting (use a clip wire) the "force defrost" connector (labeled J2 on the
board, see
) and then power ON the unit.
Please make sure the unit is turned OFF before shorting the pins. Status
Code Recall Mode will continue as long as the "force defrost" terminals
remain shorted. The unit will not attempt to cool while the terminals
remain shorted. Once the status code is read, power-down the unit and
remove the short.
Emergency Mode Connections with a Conventional
Thermostat
In an emergency, it is possible to replace the UI with a conventional
thermostat, see
for wiring. However, this emergency mode
operation is limited to a single compressor speed in cooling mode.
CAUTION
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage and/or
improper operation.
Do not use Meggar for measuring the winding resistance.