Expansion Valve With Shut-Off Valve
NOTE:
There are different versions of the shut-off valve with different functions and with different names. The following illustrated Hybrid Battery Refrigerant Shut-Off Valve 2 -N517- is for example installed on an Audi Q7 hybrid in the battery cooling module. Refer to Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information).
- The expansion valve -A- with the Hybrid Battery Refrigerant Shut-Off Valve 2 -N517- -B- atomizes the streaming refrigerant and regulates the refrigerant flow rate to the evaporator in the battery cooling module for the Hybrid Battery Unit -AX1- so that the vapor becomes gaseous only at the evaporator output, depending on the heat transmission.
- If the Hybrid Battery Refrigerant Shut-Off Valve 2 -N517- -B- is activated by the electronics and is open, it lets refrigerant flow through the expansion valve -A- to the evaporator in the battery cooling module.
- The expansion valve -A- with the Hybrid Battery Refrigerant Shut-Off Valve 2 -N517- -B- is installed on vehicles with a battery cooling module. It is activated when the A/C system is in operation, if it is necessary to cool the Hybrid Battery Unit -AX1-.
- If the Hybrid Battery Refrigerant Shut-Off Valve 2 -N517- -B- is activated by the electronics (for example, by the Battery Regulation Control Module -J840-), it is open and lets the refrigerant flow according to its control characteristic toward the evaporator in the battery cooling module.
- The Hybrid Battery Refrigerant Shut-Off Valve 2 -N517- -B- attached to the expansion valve -A- is activated, for example, by the Battery Regulation Control Module -J840-. Refer to the appropriate Wiring Diagram. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and the Battery Regulation.
- If, for a vehicle with two evaporators (one in the A/C unit and one in the battery cooling module, for example on the Q5 Hybrid), the measured temperature on one of the evaporators corresponds to the specified value or the specified value falls short, but does not reach the required specified value on the other evaporator, the following adjustment is performed: the Battery Regulation Control Module -J840- activates the electric A/C compressor with increased speed (thereby increasing the A/C system cooling output and decreasing the pressure on the low pressure side as well as the evaporator temperature) via the Electric Drive Power and Control Electronics -JX1- and the A/C Compressor Control Module -J842-. If the specified value for the temperature falls short at one of the evaporators, the Battery Regulation Control Module -J840- activates the Hybrid Battery Refrigerant Shut-Off Valve 1 -N516- or the Hybrid Battery Refrigerant Shut-Off Valve 2 -N517-, so that the evaporator which is too cold is no longer supplied with refrigerant. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System.