Nanjing Iveco A30.10 light car (middle top) Shanghai air conditioning system circuit diagram

(5) Nanjing Iveco A30.10 mid-light car Shanghai air-conditioning circuit (Figure 25).

The car uses the KQZN6-4I electronic control system. The control panel is equipped with air volume switch SA1, temperature control switch KQ and SA2, power indicator POWER cooling indicator COOL, high voltage fault indicator HP and low voltage fault indicator LP.

The air volume switching power supply still comes from the terminal G9 of the central control box of the car and is controlled by the ignition switch 15/A column. Other motor and compressor power supplies are connected from the battery positive pole (DC12V) to the contacts of the respective relays. The functions of the relays are: K1 condenser fan motor M3 relay; K2 compressor electromagnetic separator LH relay; K8 evaporation Low-speed relays for fans M1 and M2; medium-speed relays for K1O evaporator fans M1 and M2; high-speed relays for K9 evaporator fans M1 and M2.

When the air volume switch SA1 is turned on, if the element in the air conditioning refrigeration circuit fails, the pressure switches L, H, and M are all closed, and the current from the ignition switch 15/A via G9 passes through SA1 to the brown line and the white line. The power indicator POWER is on. If the temperature control switch SA2 also turns on the relays K1, K2, the air conditioner compressor LH and the condenser fan M3 are put into operation. Since the pressure switches M, L, and H are all turned on, the negative ends of the light-emitting diodes HP and LP are also at a high level via V3, V4, and V5, so the HP and LP light-emitting diodes are not lit. Only when the blue pressure switch H is disconnected, the fault indicator light-emitting diode is connected to the low level of the negative terminal, it lights up, indicating the high-voltage fault HP; when the pressure switch L and M are disconnected, the low-voltage fault is displayed.
1) I block. The K8 relay is pulled in, and the two resistors R1 and R2 are connected in series and enter the evaporator fans M1 and M2 respectively to operate at a low speed.

2) II block. The K1O relay is pulled in. Only the R2 resistor is connected in series in the motor M1 and M2 circuits to operate at medium speed.

3) III block. K9 relay pull-in, the current from the power supply (DC12V) through the fuse FB2 and relay K9 contacts, directly into the M1, M2 two motors, high-speed operation, in this block, due to the two diodes on the air volume switch, K8 The K1O relay can also be pulled in. When the high speed relay is faulty, the medium and low speed relays still function.

Freewheeling diodes V7, V8, V9, and V1O are respectively connected to the motor and the compressor circuit. When these motors are cut off, the current generated by the self-induced electromotive force can be looped through the diode to prevent damage to other electronic devices.