Ipm (Power Transistor) Protection Control; Compressor Protection Control (Gas Leak Detection Control 1); Compressor Protection Control (Gas Leak Detection Control 2); Valve Close Detection Control - Panasonic CU-2E18SBU-5 Service Manual

13.12 IPM (power transistor) Protection Control


Overheating Prevention Control
If IPM temperature rises to 176°F, outdoor fan speed will be increased.
o
When the IPM temperature rises to 203°F, compressor operation will stop immediately.
o
Compressor operation restarts when temperature decreases to 194°F.
o
If IPM temperature detected less than -22°F, IPM is judged as open circuit ("F96" is indicated).
o

DC peak current control
When IPM DC current exceeds set value of 30.0 ± 3.0 A, the compressor will stop.
o
If the DC peak current detected within 30 seconds after operation starts, compressor will restart after
o
1 minute.
If the DC peak current detected 30 seconds or more after operation starts, compressor will restart after
o
2 minutes.
Within 30 seconds after compressor restarts, if the DC peak current is exceeded set value continuously for
o
7 times, all indoor and outdoor relays will be cut off ("F99" is indicated).

Error reset can be done by power supply reset.

13.13 Compressor Protection Control (Gas leak detection control 1)


Control start conditions
For 5 minutes, the compressor continuously operates and total current is low.
o
During Cooling or Soft Dry operation:
o
Indoor intake temperature — indoor piping temperature is below 39.2°F.
During Heating operation:
o
Indoor pipe temperature — indoor intake temperature is below 37.4°F.
Not during deice control.
o
Compressor ON with maximum frequency.
o

Control content
Compressor stops (and restart after 3 minutes)
o
If the conditions above happen 4 times within 60 minutes, the unit will stop operation ("F91" is indicated).
o

13.14 Compressor Protection Control (Gas leak detection control 2)


This control detect gas leakage condition to prevent compressor damage.

Control start condition
All connected indoor units capability supply ON.
o
Compressor ON with maximum frequency.
o
Not during annual cooling.
o
Compressor discharge temperature high.
o

Control content
Compressor OFF during this control ("F91" is memorized in EEPROM)
o
If the above conditions happen 2 times within 60 minutes, indoor units' Timer LED will blinks ("F91" is
o
indicated at all indoor units)

13.15 Valve Close Detection Control


This control detects 3-way valve close condition to prevent damage to refrigerant cycle.

Start conditions:
For all connected indoor units, if Indoor intake temperature — indoor piping temperature are between 28.4°F
o
and 35.6°F continuously for 5 minutes after compressor ON at first cooling operation.
The first cooling operation is defined as cooling operation is ON for less than 8 minutes after new installation
o
or after pump down.

Control content
During this control, compressor stop, indoor units' Timer LED will blink. ("F91" is indicated at indoor units)
o

Error reset can be done by power supply reset or reset by using remote control.
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