Variable frequencydrive installation precautions

These include keeping the VFD clean, cool, dry and tight. Dust on an electronic device can cause malfunction or even failure. Dust also absorbs moisture, which aggravates the problem. Whilst periodically spraying air through cooling and heat sink fans is a good preventative measure, discharging compressed air into a variable frequency drive is generally not recommended since plant air usually contains oil and water, and there is a risk of generating Electrostatic Discharges.

A non-static spray or a reverse operated Electrostatic Discharge vacuum to reduce static build up is recommended for cleaning electronic components. Enclosure seals should be checked regularly and replaced as soon as any damage is identified. Original VFD manufacturer seals may appear expensive, but failure to replace damaged seals will result in losses that amount to significantly more than the cost of the seal.

Keep VFD cool Apart from dust on variable frequency drive hardware, which can cause airflow restrictions that insulate heat sinks and reduce the performance of cooling fans, circulating fans need to be checked for signs of bearing failure or foreign objects - usually indicated by unusual noise or shafts that appear 'wobbly'. Heat sink temperatures should be monitored regularly. Keep VFD dry The presence of moisture will lead to variable frequency drive circuit board corrosion and condemn the VFD to failure or erratic operation.

During the early design stages ensure that the VFD room is well located and that variable frequency drives are maintained in a dry area where moisture is not a problem. Keep VFD connections tight Heat cycles and mechanical vibration can lead to loose connections.

Bad connections eventually lead to arcing and result in erratic operation, causing poor variable frequency drive quality, scrap, machine damage, or even personnel injury.

Another contributing factor of loose connections is the standard preventative maintenance practice of re-torquing screws. The re-tightening of an already tight connection can ruin the connection. To avoid re-torquing, an infrared thermometer or infrared camera can be used to identify hot connections. Only when connections have become loose should they be re-tightened. Conclusion Manufacturers of VFD technology can offer end users an extraordinary level of reliability, which can be compromised if end users neglect to embrace a lifecycle approach that includes the VFD manufacturer from cradle design to grave replacement.

During the design stages, performance and selection criteria obviously merit the involvement of the manufacturer, but end users need to adjust their readiness to take over full responsibility soon after completion of the commissioning phase.

Manufacturers that recognize the importance of preventive maintenance can provide a valuable role in setting up a comprehensive preventive maintenance schedule that spans the life of the basic VFD. During the operational life of the VFD, the manufacturers can advise on basic measures to maintain the high levels of reliability of which VFDs are capable. These include keeping the VFD clean, cool, dry and the connections tight.

Their importance and impact cannot be over emphasized. Finally, as the VFDs age, end users need to work together with manufacturers to upgrade and retrofit them. Failure to adopt a proactive approach in this phase of a variable frequency drive's lifecycle will inevitably lead to reliability problems that could spill over to production bottlenecks and variable frequency drive quality.

In a technology age, VFD manufacturers need to become reliability partners who can guarantee high reliability and overall plant equipment effectiveness.

The comment to only re torque upon infra red findings is greatly flawed: 1 Only under elevated and controlled load conditions is infra red useful, so, an otherwise loose terminal will be missed if the device is not or cannot be loaded to a suitable and laboratory proven capacity resulting in a predictable "normal" temperature. I could go on but won't Most multistory apartment complexes, hotels, etc, Is VFD saving power at full load running? If the motor is running at full speed and full load via a VFD, the power drawn from the supply will be The shock load often damages connected mechanical components.

Voltage must be Short circuit faults detection for VFD-driven induction motor The problem of early fault detection in driven-variable frequency drive induction motor is a subject that is far to be completely solved. The investigation with real data sheets reveals difficulties Main factors for better life cycle of centrifugal pumps assuming the pump is properly sized, the life cycle is more often related to starts and stops.

The adverse effect of repeated starting can What is VFD, How it works? Variable Frequency Drive vs. Damper for Fans Although dampers are commonly used to control the output of fans, reducing the speed of the fan by variable frequency drive VFD is a much more energy efficient method of achieving the same In this system, if the voltage to be actually valid decreases due The soft starter is essentially robbing the motor of voltage at all points between 0 and Variable Frequency Drive Working Principle This guideline discusses variable frequency drive VFD basic working principle and how installing variable frequency drives in appropriate applications could save energy, cut costs and increase These should be taken into account before making the decision to change to variable speed The load horsepower must be known so that.

By using VFD we could vary the speed so the operation is done at different speeds and it can cause mechanical resonance in the driven equipment. Sometimes VFD can generate harmonic currents and this could baldly affect the electrical distribution system and equipment operation. So we can use a filtering device to solve this problem. We must select the VFD according to the voltage of the motor ad this is really a difficult task to achieve. We must also consider the load while selecting a VFD the load could be of variable torque or constant torque.

By using VFD we can vary the motor speed so while doing this the motor must not run less than 20 percent of its allowed maximum speed. Mostly the VFD contains three sections the input section, rectifier section, and the inverter section. The electric power from the source is drawn by the input section. If the operation of VFD goes wrong, then we must check the basics such as the connections, temperature, controller, etc.

Mostly when an error happens the proper way to troubleshoot is by the visual inspection. If there is dirt or corrosion in the drive it must be removed first. After that, the wiring connection must be checked.

Make sure all the connections are proper and check the incoming supply. All of the troubleshooting processes must be done by a qualified person. At last, the drive output voltage and current should be checked. Usually, a motor draws more current than its rated current when it is connected to a supply.

The motor rotates in a synchronous speed, so VFD is used to change this speed and it is done by changing the frequency of the applied voltage to the motor. So when a VFD is connected to the supply of the motor it will start the motor with low frequency and gradually it will increase the frequency. A VFD can convert the electrical power to a required form for controlling speed, torque, and direction of rotation of AC motor.

This rectified DC power is then transferred to the intermediate circuit which consists of inductors and capacitors. After that, it is transferred to the inverter section which will convert the DC power to AC power of variable frequency and voltage.