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Power guard RP91

Power guard RP91
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Power guard for 1- and 3-phase motors Power metering (U x I x cos j) Adjustable time-delay 0.1-30 sek. at start-up Adjustable reaction delay 0.1-30 sek Metering output indicates the power consumption 1-pole relay output 8 A / 250 VAC Produced in accordance with and EMC regulations C-mac® module type RP91 is used for power monitoring of 1-phase and symmetrical 3-phase loads, f.inst. motors. RP91 can be connected directly to loads with nominal current consumption up to 6 A; If the current is bigger, a standard current transformer is used. The unit is supplied with an adjustable start-up delay, which ensures that the output relay is activated independant of the load, when the motor is started. RP 91 is supplied for both over- and underload monitoring. The module is monitoring the total power consumption (U x I x cos j) which gives a much higher sensitivity than it is possible with the RP81. The setpoint is coarse adjusted on a 10-position switch, and fine-adjusted on a potentiometer in front of the unit, which gives a very high sensitivity on the adjustment function. When the setpoint is reached, an adjustable time-delay on 0,1 to 30 seconds starts. After this period, the relay releases, on the condition that the load has been higher than the setpoint in the whole period, in this way it is ensured, that the relay will not release in case of short changes in the power consumption. In order to get the most accurate setpoint adjustment, especially when very small loads are monitored, the unit is supplied for 4 different current ranges, and all units are available with inverted function, to detect underloads. pin 8-7. If pins 8-7 is connected, and the relay releases, it will remain released, no matter if the load changes, until the connection is opened, or the supply voltage is disconnected. Adjustments: Start-up delay: Level, coarse: Potentiometer, 0.1-30 sec. 10-position switch on the top of the unit. Potentiometer, scale 0-10 Potentiometer, 0,1-30 sec 5% Level, fine: Reaction delay: Accuracy, scale: Indications: Green LED: Red LED: Start-up: Supply voltage connected Relay activated start contact, pins 6-7. If pins 6 and 7 is connected, the relay and the start-up delay is activated, when the supply voltage is connected. This principle is used, if the unit is connected in parallel with the load. If the unit is constantly connected to the supply voltage, the start delay (and the metering) can be separately activated by connecting pins 6 and 7, f.inst. with a spare contact in the motorswitch. Technical data: Supply voltage: Supply frequency: Power consumption: Operation temp.: Humidity: Metering ranges: max. load at supply voltage: 230V 400 V 415 V int. shunt Current range 01: max. 0,6 A 270 W 450 W 480 W 1,200 W 02: max. 1,2 A 540 W 900 W 960 W 0,150 W 03: max. 2,4 A 1100 W 1800 W 2000 W 0,068 W 04: max. 6,0 A 2700 W 4500 W 4800 W 0,033 W Hysteresis: 1,3% of the total metering range Functional diagram: supply setpoinkt hysteresis Load latch contact LED, level relay, normal t2 t = selected start-up delay, t2 = reaction delay

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Ordering guide: Supply 3 x 230 V 3 x 400 V 3 x 415 V x = function: Example 1: 3-phase without current transformer. (load current smaller than 6 A) Type nr. RP91-1-3-230-xy RP91-1-3-400-xy RP91-1-3-415-xy 0 = normal (overload) 1 = inverted (underload) 2 = autostart ** ** Description autostart function: The relay activates, when the supply voltage is connected. When pins 6 and 7 is connected, the start-up time is activated, and remains activated during start-up (overload only). Example 2: 3-phase with current transformer. (load current bigger than 6 A) Note: the current transformer must...

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coarse adjustment motorswitch Start-up delay Fine adjustment stop Reaction delay Adjustment, overload function: A 10-position rotary switch, used for coarse adjustment of the setpoint is placed on top of the unit. Set the switch on 9. The potentiometer for start-up delay is set at minimum the time needed for the motor to reach its normal load/speed. Potentiometer for fine adjustment is set at minimum. Potentiometer for reaction delay is set at maximum. The motor is started, and after the start-up delay has expired, the coarse switch is gradually turned down, (9-8-7 etc.), until the relay...

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Monitoring and protection of motors and machinery. Protection of motors and machinery are normally made by means of motor switches or the like, but in many applications, f.inst, if you need a quick reaction in connection with overload, or an alarm in case of underload, it is an advantage to use a monitoring relay. Please note, that the monitoring relay cannot replace the mandatory motor switch, which is used for safety reasons. On the figures below you can see, how the different parameters are influenced by the motor load, and which C-mac relays to use for various applications. The...

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