Daikin Altherma HT Service Manual

Protection Control ESIE09-08B
56 Function
4.2 Low Pressure Protection Control
This low pressure protection control is used to protect compressors against the transient
decrease of low pressure.
In heating operation [R-410A]
Reach INV freq = MAX INV freq for each HP
• Pe>2.3MPa
or
After 10 sec.Pe<0.17MPa
Pe<0.17MPa
Pe>0.20MPa
Pe< 0.07MPa
Current step limited
After 15 sec.
Low pressure not limited
Low pressure limited
Pe<0.12MPa Pe>0.17MPa
Hot gas SVP = OFF
Hot gas SVP = ON
Pe: LP pressure sensor detection
value
INV upper limit frequency :
3-step down from current
compressor frequency
INV upper limit frequency :
1-step up from current
compressor frequency
Low pressure
standby
When occurring 3 times within 30 min., the
malfunction code "E4" is output.

Daikin Altherma HT Specifications

General

Type	Air-to-water heat pump
Refrigerant	R-410A
Water Outlet Temperature	Up to 80°C
Operating Temperature Range	-20°C to 35°C
Power Supply	3-phase, 400V
Energy Efficiency Class (Heating)	A++