Test Operation And Self Diagnosis - Panasonic CS-A24BB4P Service Manual

will not operate if the wires have been connected incorrectly, so that current will not flow to the
control circuit board. This is designed principally to conpensate human error during installation.
Prevention of connection errors
These units are equipped with connection error prevention circuits. If the units do not operate, it
is possible that the connection error prevention circuits have been operated. In such cases,
check that the power supply wires (connected to terminals [1] and [2] and the control wires
(connected to terminals [3] and [4] ) are connected correctly. If they are connected incorrectly,
connect them correctly. Normal operation should then commence.
- Do not short the remote control wires to each other. (The
protection circuit will be activated and the units will not operate.)
Once the cause of the short is eliminated, normal operation will
then be possible.
NOTE:
- Wait one minute after turning on the indoor unit power supply
before operating the remote control.
- If nothing at all appears in the remote control LCD, check the
power supply for the indoor unit. / Refer to "TROUBLESHOOTING"
chapter.
NOTE:
Do not allow any of the following connection, as such connection may damage the printed
circuit board.
- Do not connect anything except a relay to the timer input or fan
speed output (connector CNT1 on printed circuit board).
- Do not connect U-NET transmission wires to terminals 3 and 4 of
the indoor and outdoor units. (*1)
- Do not connect U-NET transmission wires to terminals A and B of
the remote control.
(1*) U-NET transmission wires are the communication wires used
for the central control.

22. TEST OPERATION AND SELF DIAGNOSIS

22.1. Test operation
- Always use a properly-insulated tool to operate the switch on the
circuit board. (Do not use your finger or any metallic object).
114