Introduction | Features |
Principles | Classifications |
Engineering Data | Further Information |
Explanation of Terms | Troubleshooting |
Incorrect Phase Sequence Protection
Preventing motor reverse operation due to incorrect wiring of a three-phase power supply (three wires).
Phase Loss Protection
Monitoring a three-phase power supply (three wires) to prevent a motor from burning out due to a disconnected wire.
Overcurrent
When a current above the rated value flows through a device (motor).
Undercurrent
The operating status of a device (motor) under an abnormally low load (such as idle running of a submersible pump).
Overvoltage
Applying a voltage that is above the rated value to a device.
Undervoltage
When the rated voltage is not being applied to the device.
Voltage Asymmetry
A voltage imbalance in a three-phase power supply (three wires).
Liquid Level Control
Controlling the level of a liquid with electrodes
(e.g., the function of the 61F).
* A relay that performs this type of control is called a Conductive Level Controller or Floatless Level Controller.
Temperature Monitoring Relay
A relay that produces an alarm for an abnormal temperature
(it does not support PID control).
Single-phase Power Supply
A power supply that uses two wires.
Example: The power supply used for a household fan.
The fan motor runs with two wires on single-phaseresidential power.
A single-phase power supply uses two wires.
Three-phase Power Supply
A power supply that uses three wires.
Examples: Almost all belt conveyors, cranes, and other industrial motors use three-phase power supplies.
The majority of power equipment (motors and heaters) used in factories runs on three-phase AC power (400 V or 200 V).
* In addition to motors, there are single-phase and three-phase heaters too.
Incorrect Phase Sequence
If the power wires to a three-phase motor are connected in the wrong sequence, the motor operates in reverse.
Phase Loss
If a wire to a three-phase motor is disconnected or was not connected, the motor cannot achieve its specified output.