Linear Expansion Valves

Linear Expansion Valves

LEV operation

Linear Expansion Valve (LEV) controls the flow of refrigerant and controls the amount of expansion through the systemThe LEV head contains a pulse motor and gears to open and close the valve to modulate the refrigerant flowThe body of the valve is where the refrigerant actually flows LEV's can be found in City Multi

LEV Head

LEV Body

• Indoor fan coils
• Outdoor units
• Branch control box (BC)

LEV control

When the power is turned on a signal is generated to close the valve to point E A second signal is pulsed to drive the valve to point A to ensure the valve is fully closed

On R410a and R32 VRF City Multi systems the valve opening ranges from: 41 pulses to 1400 pulses - Indoor fan coils 60 pulses to 1400 pulses - BC box

You can check the LEV pulse opening position using the SW4 dip switches on the outdoor unit Please note: this will show you the number of pulses being sent from the system - not the actual position of the valve

Head drives pin up/down to control flow

Indoor unit LEV

The indoor unit LEV controls the amount of expansion into the evaporator coil during cooling to maintain a superheat between 0-4k During heating mode the valve is fully open when more than 2 degrees from set point and then modulates down closer to target temperature You can check the indoor unit superheat value by using SW4 dip switches looking at TH22 liquid pipe temp and TH23 gas pipe temp

LEV Body

Refrigerant flow

Refrigerant flow