ET 174 Electrical faults in full air conditioning systems
Identifying electrical faults in air conditioning systems requires comprehensive knowledge. This knowledge includes the design and operation of the individual electrical components as well as the reading of circuit diagrams. ET 174 helps to acquire this knowledge.
ET 174 demonstrates the electrical circuit of a complex full conditioning system with heat pump function. The control circuits are actually present. The components in the load circuits are simulated (e.g. compressor, heater, 4-way reversing valve).
The air conditioning system with heat pump function cools in the summer and heats in the winter. During heating operation the defrost timer introduces a hot gas defrosting by briefly switching the 4-way reversing valve. At very low outer temperatures an electrical auxiliary heating is activated during heating operation. With low air humidity the hygrostat activates the humidifying function.
Typical protection devices, such as circuit breaker and frost protection monitor, complete the electrical circuit. The operating state of the simulated components is indicated via lamps in the circuit diagram on the front panel.
The simulation of 30 different faults, such as coil fracture in the motor or faulty relays, is possible. For fault identification the voltages or resistances at the lab jacks are checked with the multimeter. The depiction of the circuit diagram on the front panel facilitates the allocation of the measuring points.
- simulation of the electrical circuit of a complex conditioning system with humidifying and heat pump function
- investigation of key electrical components from air conditioning technology
- simulation of 30 faults
Thermostat to switch between heating/cooling
- measuring range: 1…60°C
Electrical compressor components
- start-up relay
- start-up capacitor
- operating capacitor
- overheat protection
- 2 pressure switches
Electrical components of room air fan
- start-up capacitor
- Heinemann circuit breaker
Humidifier components
- hygrostat: measuring range 30…100% r.h.
- float switch
- solenoid valve
- Heinemann circuit breaker
Defrosting components
- frost protection monitor: -10…12°C
- timer: switching time 10…60min
Circuit breaker for auxiliary heating
230V, 50Hz, 1 phase
230V, 60Hz, 1 phase
120V, 60Hz, 1 phase
- experimental unit from the GUNT practical series for the training of mechatronics engineers for refrigeration
- simulation of the electrical circuit of a complex conditioning system with humidifier and heat pump function for heating, cooling and humidifying
- real control circuits with electrical components, simulated load circuits
- electrical simulation of compressor, 2 fans (room air, outer air), 4-way reversing valve, auxiliary heating
- humidifier with hygrostat, solenoid valve and float switch (pump simulated)
- hot gas defrosting by switching the 4-way reversing valve
- operating states of the simulated components indicated via lamps in the circuit diagram
- circuit diagram depicted on the front panel
- identification of 30 faults: multimeter measures voltages or resistances at the lab jacks
- electrical design and operation of full conditioning systems
- reading and understanding electrical circuit diagrams
- design and operation of electrical components in an air conditioning system
- start-up capacitor
- start-up relay
- operating capacitor
- overheat protection
- Heinemann circuit breaker
- solenoid valve
- defrost timer
- float switch
- thermostat
- hygrostat
- frost protection monitor
- fault finding in electrical components
- in idle state
- under mains voltage