Low Pressure Protection Control - Daikin VRV III REYQ8PY1B Service Manual

Protection Control
4.2

Low Pressure Protection Control

This low pressure protection control is used to protect compressors against the transient
decrease of low pressure.
[In cooling operation]
★
Pe_min<0.34MPa
During the control
of low pressure
protection
Pe_min<0.15MPa
132
Because of common low pressure, the following control is performed in the system.
Pe_min indicates the minimum value within the system.
Normal Operation
Single type:
Compressor step of the present
situation × 0.5
Multi type:
210Hz+OFF+OFF (upper)
Pe_min<0.25MPa
Single type:
8~12HP: 52Hz+OFF
14~16HP: 52Hz+52Hz (upper limit)
Multi type:
52Hz+OFF+OFF (upper limit)
Hot gas solenoid valve (∗ 1)
ON
Pe_min<0.07MPa
Low pressure
standby
Pe_min>0.39MPa
∗1: Y4S for single system.
Pe_min>0.29MPa
Y5S for multi system.
When occurring 4 times within 30 min.,
the malfunction code "E4" is output.
SiBE37-701
Function