Table of Contents
What is over voltage fault?
An oV (DC Bus Overvoltage) fault is triggered when the DC bus voltage rises higher than the overvoltage trip point. Note: On smaller drives with a LED segment display such as the V1000 and J1000, a DC Bus Overvoltage fault will appear as “oU”. The oV trip point is approximately: 410 VDC for a 200 V class drive.
What can cause a DC bus overvoltage fault?
Probable cause:
- Braking too sudden or driving load.
- Braking unit option cannot convert the “braking energy” into heat.
- Overvoltage at the input.
- Motor short to ground.
What should be checked when troubleshooting VFD’s?
Troubleshooting VFD Problems
- Check the system with a good visual inspection.
- Clean the drive of dirt, dust and corrosion.
- Check all wiring connections for tightness.
- Check the line voltages and currents coming into the drive.
- Check the drive output for voltage and current.
How do you fix overvoltage?
POSSIBLE FIXES:
- Turn the overvoltage controller is on.
- Check supply voltage for constant or transient high voltage.
- Check the operation of brake chopper and resistor.
- Increase deceleration time.
- Use the “coast to stop” function whenever possible.
- Fit frequency converter with brake chopper and brake resistor.
What is the effect of overvoltage?
Over voltage caused by surges can result in spark over and flash over between phase and ground at the weakest point in the network, breakdown of gaseous/solid/ liquid insulation, failure of transformers and rotating machines. There are always a chance of suffering an electrical power system from abnormal over voltages.
How can overvoltage be overcome in VFD?
Extending the deceleration time is one way to solve a VFD overvoltage fault during deceleration. If extending the deceleration time does not solve the VFD overvoltage fault, a dynamic brake may be required to dissipate the excess energy.
How do you fix an overcurrent fault?
If incoming voltage is too low, or the acceleration rate is set too fast, an overcurrent fault is possible. Decrease the acceleration rate or stabilize incoming voltage to correct this fault.
How do you test overvoltage protection?
An easy way to do this is to find the feedback resistors and connect a potentiometer in parallel with the lower one (the one that connects to ground). Slowly and carefully reduce the resistance of the potentiometer while monitoring the increasing output voltage.
What does battery over voltage mean?
overvoltage condition, the device immediately. – Battery Overvoltage. removes power from the charging circuit by turning. • Maximum Input Voltage of 30 V. off an internal switch.
How can overvoltage be prevented?
There are many different ways to protect your circuit from overvoltage. The simplest way is to connect the fuse at the input supply side. But the problem is that it’s a one-time protection, because as the voltage exceeds the preset value, the wire inside the fuse will burn and break the circuit.
Which are most affected by overvoltage?
Small motors tend to be more sensitive to overvoltage and saturation than do large motors. Single-phase motors tend to be more sensitive to overvoltage than do 3-phase motors. U-frame motors are less sensitive to overvoltage than are T-frames.
What causes an overcurrent fault?
An overcurrent occurs when the current exceeds the rated amperage capacity of that circuit or of the connected equipment (such as an appliance) on that circuit. An overcurrent can be caused by overloading the circuit or by a short circuit, a ground fault, or an arc fault.
What will trigger if an overcurrent is detected in a circuit breaker?
In the event of an overcurrent situation, fuses will blow or circuit breakers will trip. Although these devices protect the circuit against overcurrent conditions, they only open the circuit and disconnect the supply of electricity.
How do you stop overvoltage?
The solution is to install a surge protector, which will act as a safety shield for the equipment, against any unwanted voltage spike. It is a simple device capable of reacting with impressive speed to any possible overvoltage.
How do you fix an overvoltage battery?
For Overvoltage you may need to replace the whole USB port part of the circuit board (easily obtainable on EBAY) and you have to replace the battery at the same time as well cause the battery (also easily obtainable off ebay) gets damaged with the overvoltage problem.
What happens if overvoltage?
The overvoltage can cause excessive current to flow as well as creating excessive voltage stresses. In both cases, the electrical insulation system inside the motor or equipment can be degraded reducing life or causing damage.
What is a bus over-voltage fault?
To provide a little more detail: A bus over-voltage fault means that the bus voltage level has exceeded the maximum value specified for the VFD in question, and the VFD engages in a fault to protect DC bus components. The tables below provide the trip levels for particular 750-series and 5-series drives at 480 Volts input:
How to calculate overvoltage fault on a VFD?
Comparing Overvoltage trip thresholds with the nominal DC bus voltage we can see that the overvoltage trip settings for most drives is 130-150% of nominal DC bus voltage. Corresponding AC voltage at which overvoltage fault occurs can be calculated by dividing the above values by 1.35. Typical Reasons for having an Overvoltage Fault on VFD
What causes the drive to trip on overvoltage fault?
This causes the DC bus capacitors to get charged to a higher voltage level. Under severe distorted waveform cases, this could cause the drive to trip on overvoltage fault. Solution: The solution to this problem will be to fix the voltage harmonic issue and hence bring the voltage crest factor to a nominal value.
What could cause a DC link overvoltage fault event?
Any and all events that could cause a jump in DC bus voltage could lead to a dc link overvoltage fault event. This guide will help you in troubleshooting VFD problems with overvoltage fault code.