Home           Products           Company           Contact us     
> Fundamentals of Thermodynamics
> Applied Thermodynamics
> Renewable Energies
> Power Engines and Machines
> Internal Combustion Engines
> Refrigeration and Air Conditioning Technology
> Heating and Ventilation in Buildings
> Sanitary Systems
Products  |  Thermal Engineering and HVAC  |  Refrigeration and Air Conditioning Technology  |  ET 171
ET 171 Electrical Connection of Refrigerant Compressors Show data sheet (pdf file) Print page
Technical Description

  The wiring of electrical components for the start and operation of refrigerant compressors is a typical task in the field of refrigeration. Safety aspects also play an important role. With ET 171 this knowledge and these skills can be acquired. All components are operated and tested with mains voltage to provide high relevance for practice.
  The electrical components for the start and operation of the refrigerant compressor are arranged clearly visible. The electrical connection of the individual components is made with cables via the lab jacks. The components are e.g. the capacitor and start-up relay necessary to start the motor. The circuit diagram on the front panel enables the easy allocation of the individual components.
  The refrigeration circuit with compressor and receiver enables the checking of the pressure switches on the intake and delivery side of the compressor. The pressure is set via valves and the pressure switch tripped. Two manometers enable the monitoring of the pressure curve. If one of the pressure switches trips, the current supply to the compressor is interrupted. The wiring and checking of other typical components of the safety chain, e.g. circuit breaker and automatic fuse, is also carried out.
  The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- Read, understand, wire and test electric circuit

  diagrams for refrigerant compressors
- Design and operation of electrical components of

  refrigerant compressors
  * start-up capacitor
  * start-up relay
  * overheat protection
  * automatic fuse
  * pressure switch
  * thermostat
- Design and testing of a safety chain
- Representation methods in electrical engineering
  * symbols
  * circuit diagrams
- Safety aspects when handling mains voltage


* Correct electrical connection of a refrigerant

* Use of a real refrigerant compressor1
* Design and investigation of a safety chain

Alternative products
ET 144 -- Electrical Installation in Refrigeration Systems
ET 170 -- Electrical Faults in Simple Air Conditioning Systems
ET 172 -- Electrical Faults in Refrigerant Compressors
ET 174 -- Electrical Faults in Full Air Conditioning Systems
ET 340 -- Building Automation in Heating and Air Conditioning Systems
ET 930 -- Evaporator Control with Electronic Expansion Valve
[1] Experimental unit from the GUNT practical series for the training of mechatronics engineers for refrigeration
[2] Correct electrical connection of a refrigerant compressor
[3] Refrigerant circuit with compressor, receiver, 2 valves and 2 manometers to investigate pressure switches on the delivery and intake sides
[4] Electrical components for the start and operation of the compressor mounted clearly visible
[5] Lab jacks and cables to connect the electrical components
[6] Operation of a thermostat
[7] Circuit diagram on the front panel for easy identification of the components
[8] Refrigerant R134a, CFC-free
Technical Data

Refrigerant compressor
- power consumption: approx. 165W
Receiver: 0,8L
Manometer measuring ranges
- delivery side: -1...24bar
- intake side: -1...9bar
Pressure switch control range
- delivery side: 8...32bar
- intake side: -0,9...7bar
Thermostat: -5...35C
Electrical components for the compressor
- start-up capacitor

- start-up relay
- overheat protection (bimetallic)
- automatic fuse


Dimensions and Weight
l x w x h: 900x400x650mm
Weight: approx. 35kg
Required for Operation
230V, 50Hz, 1 phase
Scope of Delivery
1 experimental unit
1 multimeter
1 set of laboratory cables
1 set of instructional material
Order Details

061.17100  ET 171  Electrical Connection of

                                 Refrigerant Compressors

© 2005 G.U.N.T. Gerätebau GmbH