What is a soft start fault?
What is a soft start fault?
A combination of voltage spikes, too many starts per hour, or too much current during a start will destroy a soft starter. Phase imbalance for either voltage or current will cause an SCR to fail, as will a single phase condition on a 3-phase motor.
Why do soft starters fail?
A combination of voltage spikes, too many starts per hour, or too much current during a start will destroy a soft starter. Phase imbalance for either voltage or current will cause an SCR to fail, as will a single phase condition on a 3-phase motor. What also needs to be considered is the load being started.
What is the starting current for soft starter?
For this motor, the initial current when it is started is 600 percent, or six times the motor’s full load current rating . The soft starter can be set to reduce this current, for example, in this case, to 300% . This limits the inrush current on the utility line .
What is the difference between soft starter and VFD?
The main difference between the two is that a VFD can vary the speed of a motor while a soft starter only controls the starting and stopping of that motor. When faced with an application, price and size are in the favor of a soft starter. A VFD is the better choice if speed control is required.
How do you troubleshoot a soft starter?
Restart the soft starter. To reset the soft starter, press [Reset] or activate the Reset remote input. If the soft starter has issued a warning, it resets itself when the cause of the warning has been resolved. Table 10.1 lists the protection mechanisms in the soft starter and the probable cause of the trip.
How do I test a thyristor soft starter?
Disconnect the supply and the motor from the soft starter, Measure the resistance of the SCRs using a 500V insulation tester such as a megger. This can be done with the electronics connected, no damage will be caused by the 500V tester. Test from L1 to T1, L2 to T2 and L3 to T3.
How do I know if my soft starter is bad?
Soft starter gives failure warning when starting, it can’t work and the motor doesn’t run. Possible causes may be: Phase absence of motor (check motor and peripheral circuits). Silicon control of main component in the soft starter shorts (check whether the motor and grid voltage are abnormal.
How do I test a soft start?
What is the difference between star delta and soft starter?
However, the main differences are: A number of states: Star delta starters only have two states, low voltage, and full voltage, that the starter jumps between. Soft starters, on the other hand, start-up gradually. With star-delta starters, you can’t adjust the starting torque.
What is inrush current in soft starter?
Across-the line starting of induction motors is accompanied by inrush currents up to 7-10 times higher than running current (inrush current can reach levels of 10 -15 times for higher efficiency motors), and starting torque up to 3 times higher than running torque.
