DWB01 and PWB01 are precise TRMS power factor monitoring relays for 3- phase balanced systems.

They can be used for monitoring the actual load of asynchronous motors and other symmetrical loads, where the power factor is almost proportional to the load.

The relay measures the power factor (cos ϕ), that is the ratio between the active and the apparent power of a motor.

Start/stop input allows to use a manual switch to start and stop the motor, without the need of an auxiliary device.

The advantage of using the latch function is that the relay can be kept energized even after the end of the alarm condition. Inhibit function can be used to avoid relay operation when not desired (maintenance, transients).

The LED’s indicate the state of the alarm and the output relay.

Features

• TRMS load guard relays for three phase balanced applications

• Measuring if the power factor is within set limits

• Measure their own power supply

• Measuring ranges: 5A, 10A, MI current transformers

• Power ON delay 1 to 30 s knob adjustable

• Separately adjustable upper/lower level on absolute scale

• Programmable latching or inhibit at set level

• Automatic and manual start and stop of the system

• Output: 8 A SPDT relay N.D. or N.E. selectable

• For mounting on DIN-rail in accordance with DIN/EN 50 022 (DWB01) or plug-in module (PWB01)

• 45 mm Euronorm housing (DWB01) or 36 mm plug-in module (PWB01)

• LED indication for relay, alarm and power supply ON