Service manual

ESIE03–01 General Functionality

Part 2 – Functional Description 2–15

1.9 Simulated Operation Function

Applicable units P R(Y)P71-125L

Purpose The purpose of the simulated operation function is to avoid the unit from stopping if the heat exchanger

thermistor or air thermistor is malfunctioning.

Method If the air thermistor (for all models listed) or the heat exchanger thermistor is malfunctioning (out of its

normal range), simulated operation is carried out while malfunction is displayed on the remote

controller. If the air or heat exchanger thermistor becomes normal again, the simulated operation

function is interrupted and the normal operation restarts. The malfunctioning error disappears.

Used input The simulated operation function uses the following inputs:

Parameters

P Check sensor valve every 500 msec’s.

P Abnormal values are sensor values out of below range :

Input

Connection on

indoor PCB

Connection on

outdoor PCB

Outdoor air thermistor — R1T-X4A

Outdoor heat exchanger thermistor — R2T-X5A

Indoor air thermistor R1T-X19A —

Indoor heat exchanger thermistor R2T-X18A —

Sensor Lower than… Higher than…

Indoor coil and air sensor -23°C 120°C

Outdoor coil and air sensor -40°C 127°C

Sensor

abnormal

normal

20 sec’s

malfunction confirmation

(remote controller error indication)