Defrost Operation In Heating Operation Stopped - Fujitsu AUUH18LUAS Service Manual

6-1. Defrost operation in heating operation stopped

If the outdoor unit is frosted when stopping the heating operation, it stops after performing the auto-
matic defrosting operation.
In this time, if the indoor unit operation lamp flashes slowly (6 sec on/2 sec off), the outdoor unit al-
low the heat exchanger to defrost, and then stop.
Triggering condition
•
→hen all of the following conditions are satisfied in heating operation
– Compressor operation integrating time: 30 minutes or more
– Compressor continuous operation time: 10 minutes or more
– Outdoor unit heat exchanger temperature: 24.8°F (-4°C) or less
Release condition
•
– Model: AOUH18LUAS1
Depending on the triggering condition, different release conditions apply.
• Normal defrost operation
The defrost operation is released when either one of the conditions below is satisfied.
Outdoor unit heat exchanger temperature
(after 1 minute or later since compressor start)
Compressor operation time
• Integrating defrost (constant monitoring)
The defrost operation is released when either one of the conditions below is satisfied.
Outdoor unit heat exchanger temperature
(after 1 minute or later since compressor start)
Compressor operation time
– Models: AOUH24LUAS1, AOUH30LUAS1, and AOUH36LUAS1
The defrost operation is released when either one of the conditions below is satisfied.
Outdoor unit heat exchanger temperature
(after 1 minute or later since compressor start)
Compressor operation time
6-1. Defrost operation in heating operation stopped
55.4°F (13°C) or more (Ta ≤ 33.8 °F [1 °C])
50.0°F (10°C) or more (Ta > 33.8 °F [1 °C])
55.4°F (13°C) or more
53.6°F (12°C) or more
- (04-28) -
15 minutes
15 minutes
15 minutes
6. Defrost operation control