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Load guard RP81

  • Load guard for 3-phase motors
  • Power factor metering (cos _)
  • Adjustable time delay 0-20 sek. at motor start
  • Selectable release of relay at max. or min. load
  • 1-pole relay output 8A / 250 VAC
  • Produced in accordance with CE and EMC regulations

C-mac® module type RP81 is used for load monitoring of 3-phase motors, as the phase angle (cos _) between motor current and -voltage changes in proportion to the mechanical load of the motor.
You will see the biggest change in phase angle, if the motor is loaded between 0 and 60% of nominal load, which makes the RP81 suitable for monitoring of V-belts, pumps running dry, etc. (see page 6-6).
RP81 can be connected directly to motors with nominal current up to 6 A. If the current is bigger, you use a standard current transformer.
The unit is supplied with an adjustable start-up delay, which keeps the output relay activated independant of the power consumption, when the motor is starting.
By connection of pins 7 and 2 you can select if the relay releases at over- or underload.

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