DETAILED DESCRIPTION

DWB01.. & PWB01..

Precise over and under cos φ monitoring relays for the actual load of asynchronous motors.
The relays measure the 3-phase supply voltage and the current of the phase L1 connected to an asynchronous motor.
The relay monitor the cosine of the angle between motor current and motor voltage (cos φ).
As cos φ varies with the load of the motor, overload (or underload) can be indirectly detected by DWB01 and PWB01.
The relation between the load and cos φ depends on the type of motor. As a guideline to ensure correct working conditions for a motor, the level could be set above (or below) the cos φ marking on the motor. It is however recommended to make the adjustment in connection with a practical test.
The relay has an inhibit delay at power ON in order to avoid overload detection during motor start.
The relays monitor their own power supply voltage and the current of a balanced 3-phase system.
For current measure direct connection (5 or 10 A) or 5A standard current transformers and MI CT can be used.
The LED's indicate the state of the alarm and the output relay.

Specification

• Supply and metering zone: 208 - 240 , 380 - 415 , 380 - 480 , 600 - 690 (depending on model)
• Power factor (cos φ) measuring range: 0,1 - 0,99
• Detection function: overload and underload
• Latching or inhibit at set level: Programmable
• Current input: 5 A, 10 A or CT/5A or CT type MI
• Current transformer: secondary 5 Α (standard CT) or up to 500 A (MI series) 
• Power ON delay: 1 - 10 s
• Output: 1 SPDT relay 8 A
• Mounting: on DIN-rail in or plug-in module