Eev Control - LG ATNH126ELFC Service Manual

Outdoor Units

1.3 EEV Control

1) The base(the first stage) open_degree's establishment
The base open_degree is established [the standard open_degree classified by indoor_Type and capacity ]
that corrected to the indoor/outdoor Temp.
2) Starting Control (LEV target open_degree arrival process after starting Comp)
(1) LEV is arrived the previous decided open_degree within 30 seconds after starting COMP.
(2) The open-degree is increased to target_degree in proportion to Comp operation time.
The starting control°Øs time is within 120 seconds after COMP operation
3) Normal Control
: The condensor's degree of superheat control + Compressor Discharge-Temp. Control
(1) Cooling mode
In cooling mode, normal control regulates EEV pulse that continues to fixed value for Superheat Temp. of
the operating indoor unit.
Control subject : The pipe Temp. of outdoor_unit
T_Target : The pipe Temp. of indoor_unit + The degree of superheat
(2) Heating mode
In heating mode. It is used the degree of superheat control that be regular the difference with Compressor
Suction pipe-Temp. (ACCUM) and pipe Temp. of outdoor_unit
The degree of superheat = Compressor Suction pipe_Temp. (ACCUM) – The pipe Temp. of
outdoor_unit
Control subject : The suction_pipe of indoor_unit
T_Target : The pipe Temp. of outdoor_unit + The degree of superheat
(3) EEV control
a. Superheating control (Cooling Mode)
- Superheating
- LEV pulse up
- LEV pulse down : T superheating < 2°C
b. Target Temperature Control (Cooling mode)
- In case, outdoor temperature > 39°C
- Target superheating : T target = Tin = 18°C
- LEV pulse up
- LEV pulse down
c. Target Temperature Control (Heating mode)
- LEV pulse up
- LEV pulse down : T target < Tout
d. LEV pulse change Value
8 pulse (P1-P0 > 4°C)
4 pulse (4°C ≥ P1-P0 > 3°C)
2 pulse (3°C ≥ P1-P0 > 1°C)
140 Synchro Air Conditioner
: T superheating = Tout – Tin = 2°C
: T superheating > 2°C
: T target < 18°C
: T target > 18°C
: T target > Tout