Protection Control; High Pressure Protection Control - Panasonic Mini UM S Service Manual

Mini UM S/M

4. Protection Control

4.1

High Pressure Protection Control

This high pressure protection control is used to prevent the activation of protection devices due
to abnormal increase of high pressure and to protect compressors against the transient
increase of high pressure.
[In cooling operation]
Pc > 3.4MPa
High pressure limited
Pc < 3.3MPa
INV upper limit frequency:
1-step up from current
compressor frequency
[In heating operation]
High-pressure drop
High pressure not limited
Pc > 3.3MPa
High pressure
limited
High pressure
standby
Function
High pressure not limited
or
INV upper limit frequency :
1-step down from current
compressor frequency
Every 10 sec. Pc > 3.45MPa
Keeping the current step
3.3MPa≤Pc≤3.4MPa
Every 60 sec.
Pc>3.6MPa
High pressure
standby
Pc < 3.1MPa
52Hz
Pc > 3.6MPa
When HPS is activated, the
malfunction code "E3" is output.
Pc: HP pressure sensor detection value
• INV upper limit frequency
&
• Pc ≤ 3.4MPa
• During oil return operation
• After oil return operation
• Stopping operation
• Heating operation
Every
5 min.
INV upper limit frequency:
1-step up from current
compressor frequency
When occurring 3 times within 30
minutes, HPS is activated without high
pressure standby, thus outputting the
malfunction code "E3".
Pc: HP pressure sensor detection value

Protection Control

(V3173)
(V3174)
45