Load guard for 3-phase motors Power factor metering (cos j) 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 and EMC regulations C-mac® module type RP81 is used for load monitoring of 3-phase motors, as the phase angle (cos j) 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. Relay function: When the supply voltage is connected, the output relay activates, and the start-delay will start, independant of the selected relay function. pins 2-7. If pin 2 is not connected, the output relay releases immediatly, if the power factor exceeds the set level, provided that the set start-delay has run out. If pin 2 is connected to pin 7, the relay releases, if the power factor is lower than the set level, and the timer has run out. Functional diagram: supply Technical data: Supply voltage: Supply frequency: Power consumption: Operation temp.: Humidity: Monitoring current: Internal shunt: Hysteresis: Adjustments: Start delay: Level: Accuracy, scale: Start delay: Level: Indications: Green LED: Red LED: 3 x 230 V +/- 10% 3 x 400 V +/- 10% 3 x 415 V +/- 10% 40-70 Hz 2,5 VA -20°C to +60°C 0 - 90% RH, non-condensing min. 0,5 A, max. 6 A At bigger currents use a standard current transformer.. 33 mW. At max. current 6 A the voltage across the shunt is 0,2 V 5% of adjusted level. setpoint hysteresis load relay, ex. 1 relay, ex. 2 t = selected start-up delay ex. 1: overload, pins 2-7 open ex. 2: underload, pins 2-7 connected Potentiometer, 0-20 sec. Potentiometer, cos.j 0-0,9 20% 5% Supply voltage connected Relay activated

Ordering guide: without current transformer. (motor current smaller than 6 A) With current transformer. (motor current bigger than 6 A) Note: the current transformer must be connected as shown (P1 / P2 and S1 / S2) C-mac Control module 4 Supply Relay Materials and weight: Housing: NORYL-SE-1, grey, self-extinguishing Housing bottom: NORYL SE-1, GFN-2, black, self-extinguishing Terminals: Nickel-plated brass Weight: 110 g