Embraco – multi-national focused on innovation and one of the largest manufacturers of hermetic compressors for refrigeration – wants to be part of its customers’ business before, during and after the purchase. Installing and working with compressors require attention, therefore the company’s Distribution and Retail segment supports sales teams, technicians and professionals of the segment as well as conducts annual surveys and promotes lectures and trainings.
Always attentive to offer innovative solutions not only in products but also in services, especially those aimed at facilitating the day to day of industry professionals, Embraco has launched a digital tool, called Toolbox app that combines several features focused on providing support to contractors in a single application. The company developed main practices for installing compressors to help them in their daily work. All the recommendations below explain the ways to work with compressors and to check if the work has been carried out with complete safety and precision.
Diagnosis and Maintenance Procedures in Cooling Systems
- Ensure beforehand that the environment for maintenance is suitable and airy.
• Have at hand the process tools and equipment.
• Use the PPE (personal protection equipment) required for your activities.
• Before starting the maintenance or diagnosis, first check that the cooling system is disconnected from the electrical network.
• Wait for the compressor to cool, with the system already disconnected from the electrical network. Only execute maintenance or diagnostic procedures with the compressor cold (25°C ± 5°C).
• Only connect the compressors in electrical installations with DR (Differential Residual) circuit breakers.
• Check that the installation has the correct grounding.
It should be emphasized that not disconnecting the compressor from the electrical network during maintenance procedures and the application of a system without DR circuit breaker can cause serious risks to the technician’s physical integrity due to the possibility of electric shocks and/or fire occurring.
Furthermore, not disconnecting the compressor from the electrical network can, if there is a short circuit in the region of the compressor hermetic terminal, cause the hermetic pins to be expelled, causing the leakage of the cooling fluid.
Electrical Accessories
- Before removing the plastic cover protecting the electrical components, check that the compressor is disconnected from the electrical network and that start and/or functioning capacitors are used.
• Remember to never handle any electrical accessory with the compressor connected to the electrical network. Not disconnecting the compressor from the electrical network during maintenance procedures can cause serious risks to your physical integrity, as has already been said.
• Start and/or functioning capacitors must be handled with care, as they can cause an electric shock even if they are disconnected.
• When it is necessary to remove the capacitors, disconnect them carefully, paying special attention to the exposed electrical terminals. After being disconnected, the capacitor must be discharged.
• Check that the capacitance range (µF) printed on the start and functioning (if applicable) capacitor label is in accordance with the technical information of the compressor installed in the system. The VAC Voltage value printed on the capacitor must be equal to or greater than the value indicated in the technical information of the compressor. If one of the values (VAC Voltage and/or Capacitance) is not in accordance with the specification of the compressor, replace the capacitor.
• The application of an unsuitable capacitor and/or start devices (relays or PTC) not specified can cause overheating of the capacitor. Overheated capacitors are subject to rupture, which can lead to leakage of overheated material, generating risks of burns.
• When it is necessary to disconnect the electrical components of the compressor hermetic terminal, remove the thermal protector and start device (relay or PTC), applying longitudinal force on the pins. Never apply transversal forces on the pins of the hermetic terminal.
• The inappropriate removal of these accessories can cause poor contact in the electrical connection, damage the hermetic terminal and cause the pins to be expelled leading to the leakage of the cooling fluid and oil.
• Compare the code printed on the thermal protector, relay or PTC with that of the technical information of the compressor. If the code is different, replace the component outside the specification. There are no universal or similar electrical accessories. Always use the model specified in the technical information of the compressor.
• Remember that start devices (relays or PTC) not specified can cause overheating of the capacitor. Overheated capacitors are subject to rupture with the consequences already mentioned.
• The use of thermal protector or start device (relay or PTC) differing from the one specified can generate a short circuit in the region of the compressor hermetic terminal. This can cause the hermetic pins to be expelled, leading to the leakage of the cooling fluid.
Electrical Installation
In single-phase installations, the Phase wire must be protected by a circuit breaker and connected to the thermal protector. The Neutral wire must be connected to the start device (relay or PTC). The system must be grounded. This situation is presented in the Figure 1.
While in two-phase installations, as shown in the Figure 2, it is mandatory to use the two-pole circuit breaker. With this, in the case of a short circuit both the power supply phases will be protected. The system must be grounded.
Not using a two-pole circuit breaker leaves the compressor susceptible to short circuit in the region of the hermetic terminal, being able to cause the hermetic pins to be expelled and lead to the leakage of the cooling fluid. Bear in mind, also, that in systems without grounding there are risks of electric shock.
Replacing the Compressor
If it is necessary to replace the compressor, pay attention to the following safety recommendations:
- Check that the compressor is disconnected from the electrical network. Not disconnecting the compressor from the electrical network during the maintenance procedures can expose the technician to the risk of electric shock and fire.
2. Never remove the compressor before removing all the cooling fluid from the system. For this operation, it is advisable to use a fluid collecting machine. In the case of flammable fluids, ensure that small accumulations of cooling fluid of the system are removed, as they can generate risk of fire.
3. Use a pipe cutter to disconnect the pipes of the compressor. Under no circumstances use the blowtorch flame to disconnect the compressor pipes. Using a blowtorch in compressors with flammable cooling fluid can cause fire and release toxic vapors.
4. In case of burning of the compressor and/or internal contamination of the system, clean the piping with an appropriate solvent, applied as per the manufacturer’s technical guidelines. Non-compliance with the solvent manufacturer’s technical guidelines can expose the technician to risks of fire and intoxication.
5. Before connecting a compressor ensure the following:
- The voltage on the compressor label is appropriate for the electrical network and the electrical installation is in accordance with that described in the topic ‘Electrical Installation’. The application of a compressor at the incorrect voltage can generate a short circuit in the region of the hermetic terminal, with the consequences described previously.
The plastic protection cover of the electrical components must be suitably fitted. Not using or positioning this plastic cover inappropriately generates a risk of electric shock and fire.
