General purpose and application
Fault indicator CPZ®-3MFA can be used in cable networks or overhead transmission lines:
• compensed with automatics ACFA,
• with constantly grounded neutral point by means of a resistor,
• with constantly or momentary isolated neutral point.
Fault indicator CPZ®-3MFA is designed for interior stations. It is composed of a sensor which is a transreactor transformer coupled in a configuration with magnetic summation (Ferranti system) or in a configuration with electrical summation (Holmgreen system) and a switchboard connected to a secondary circuit.
A two-coloured lamp is the signalling element. The switchboard is provided with own source of power supply and a transmitter with shorting contacts accessible on output terminals what, in case of a failure, gives a possibility to transmit a signal about short circuit through remote control systems.
Advantages of application
• Definitely shorter time of cable damage location, and thus shortening of interruptions of electric power supply.
• Lower probability of a damage to line or transformer due to decreasing number of short circuiting connections, and in effect the prolongation of life of devices due to elimination of unnecessary connections with short circuit current.
• Tentative result of erasing the CPZ®-3MFA excitation provides information about the passage or decay of short circuit current, hence the risk of opening a disconnector during the passage of a short circuit current is minimized.
• Signalling of transient faults in a successful SPZ cycle.
Download a catalogue| Basic technical data | ||
| Threshold of current activation for ground faults | Sub-range I
5 ÷ 80 A every 5 A ± 5% Sub-range II 10 ÷ 160 A every 10 A ± 5% |
|
| Threshold of current activation for phase-to-phase faults | (250, 500, 750, 1000) A
± 10% |
|
| Threshold of fault duration | Sub-range I
50 ÷ 750 ms every 50 ms ± 1 ms Sub-range II 100 ÷ 1500 ms every 100 ms ± 2 ms |
|
| Alert duration | 2 or 4 hours | |
| Alert type | • two-coloured lamp red-green
– red – ground fault alert – green – phase-to-phase fault • operating contact of relay |
|
| Alert erasing | • automatic after preset alert time
• by pushing a button on switchboard • automatic after return of power supply in switchboard • automatic after 60 s in case voltage decay in switchboard does not occur within 60 s from excitation |
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| Minimum interruption time of voltage cut in SPZ cycle | 1 s | |
| Power supply of switchboard | 230 V AC +10% -15%, 50 Hz | |
| Power consumption of switchboard | ≤ 2 VA | |
| Power supply support | Battery 12 V / 0,8 Ah | |
| Switchboard housing | Wall mounting box (196 x 113 x 157) mm (H x D x W) | |
| Housing protection level | • transformer IP40
• switchboard IP54 • lamp IP54 |
|
| Working temperature range | (-25 ÷ +55)°C | |
