Fisher PTTW-10-EC Series Engineering Manual page 30

Through the wall air conditioners

Table of Contents

2.6.4.2 When IPT sensor is damaged

When IPT is lower than -30℃ or higher than 90℃，it is judged to be damaged；

Note：After IPT sensor is damaged, the green light will flash with 0.5Hz frequency, or the unit

will display E2 on the panel.

2.6.4.3 When OPT sensor is damaged

When unit is In heating mode, compressor runs for 50 minutes, and then defrosts 3 minutes.

2.6.4.4 When RT and IPT sensors are damaged at the same time

Protection function will be according to 2.6.4.1a.

2.6.5 Indoor PG motor failure protection

If there is no fan speed feedback pulse from the PG motor after the motor has been powered

on for 5 seconds, indoor fan motor, compressor, outdoor fan motor, valve and electric heater

will stop. After 10 seconds, PG motor will be powered on again. If the fan speed feedback

signal from the motor is still absent, it will be judged as PG motor failure. Green Light will flash

1.5S/Stop 0.5S, and the unit will display E3 on the panel.

2.6.6 Refrigerant insufficient protection

In cooling mode or cooling in auto mode, compressor operators for 20 minutes, if indoor coil

temperature ≥ room temperature - 5℃, and time lasts to 40 minutes, unit will stop working and

display E4 on the panel.

In heating mode or heating in auto mode, compressor operates for 20 minutes, if indoor coil

temperature ≤ room temperature + 5℃, and time lasts to 40 minutes, unit will stop working

and display E4 on the panel.

2.6.7 Failure Code

Failure means the system cannot self adjust. Turn off the unit and report the error code to

your service centre. Error code:

Failure situation

RT Sensor Failure

IPT Sensor Failure

Indoor PG Motor Failure

Insufficient Refrigerant

2.6.8 OPT failure protection

The OPT sensor is used for the defrost function in heating mode. If OPT sensor works well,

the unit will check the data from OPT sensor, then decide if defrost function is necessary.

Please refer to 2.1.4.

THROUGH THE WALL UNIT

Light flash

1 time

2 times

on 1.5 sec./Stop 0.5 sec.

on 1.5 sec./Stop 1 sec.

Code

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