沧灿郑5GN36K东方马达
Detecting Overvoltages

Detecting overvoltages can be difficult. Sometimes all that is known is that the pulse transformer sparked over. It is easy to conclude that the transformer is defective, since that was the only obvious thing that happened.

The first check is to be certain the oil is up to standard. Then one should watch for larger than normal secondary and primary pulses. This can be difficult, because the malfunction may occur just the moment one takes his eyes off the scope. Also a single high pulse will often not occur during the normal triggered sweep time of the scope trace. One better way is to monitor the
PFN voltage with a reliable voltage divider. A high charging cycle here can be detected more easily. Another possibility that does not require such? close watching is to POSTTTION the normal scope trace so that it is just off the scope screen. By turning the intensity very high and using a scope screen that has some persistence (e.g. P2) an overvoltage will fall on the visible part of the screen and the intensity of the spot and the persistence of the screen will allow viewing after the event.

Bifilar Heater Current Protection

A rare problem, but one worth including, is for the case of a bifilar transformer carrying heater current, that sparks between the two legs of the bifilar. There is normally not enough current in the pulse circuits to damage the transformer windings. But the high-voltage spark is followed by a heavy current arc fed by the heater supply. If not properly fused or circuitbreaker protected, this heavy current arc can burn the transformer windings through, resulting in an open winding. If pulsing is continued, this break in the winding will spark over continuously with the pulses, rapidly carbonizing the oil and causing further breakdowns.
Clamp?On Current Monitors

Current Transformer?|?Current Probe?|?Current Transducer
Current Toroid?|?Current Sensor?|?Pulse Current Monitor
High Frequency Current Transformer

Accuracy ±1% or better, initial pulse response for all models, with a high impedance load such as 1 megOhm in parallel with 20 pF. A 50 Ohm termination will reduce the output to half. All models listed below come with a BNC connector except as noted and are to be used with a 50 Ohm coaxial cable. The?current monitor?case is conductive and not insulated. Adequate insulation must be provided on the conductor being monitored. To avoid electrical shock, do not mount or remove the?current monitor?from a live conductor.

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Time Domain Parameters Frequency Domain Parameters

Shape Output
(click to expand) (Volts/ Hole Id.
Model # Amp) (inches) Useable Max. 3dB 3dB I/f I2t max
Peak Rise RMS pt. pt. (RMS (Amps
Curr. Droop Time IT Max. Curr. Low High Amps squared
(Amps) (%/μsec.) (nsec.) (Amp-sec.) (Amps) (Hz) (MHz) /Hz) ?sec)
?8585C N 1 0.5 500 1 2 0.003 5 1,500 200 0.01 5
4100C N 1 0.5 500 1 15 0.0015 5 1,500 25 0.008 150
8590C M 1 1 500 0.7 2.5 0.002 5 1,000 150 0.01 25
7790 M 1 1 500 1 15 0.002 5 1,500 25 0.01 150
4688 L 1 2 500 0.4 12 0.005 15 600 30 0.03 150
8705C? - 1 2 15 4 1 0.0006 4 1,500 400 0.002 0.02
7805 K 1 4 500 0.7 25 0.004 15 1,000 25 0.02 150
7760 J 1 6 500 0.5 50 0.005 20 750 7 0.03 350
5101 L 0.5 2 1,000 0.1 20 0.02 25 150 18 0.08 700
5949? K 0.5 4 1,000 0.1 30 0.02 30 150 12 0.08 700
411C N 0.1 0.5 5,000 0.015 20 0.15 50 25 20 0.7 18,000
7795 M 0.1 1 5,000 0.015 25 0.15 60 25 15 0.8 18,000
3525 L 0.1 2 5,000 0.004 25 0.5 100 6 15 2.5 18,000
7810 K 0.1 4 5,000 0.007 50 0.4 150 10 7 2 18,000
7655 J 0.1 6 5,000 0.007 100 0.4 175 10 4 2 35,000
5008C N 0.01 0.5 50,000 0.005 150 1 150 7.5 3 4.2 250,000
7800 M 0.01 1 50,000 0.003 175 0.8 125 5 2 4 140,000
4160 L 0.01 2 50,000 0.001 200 2.5 300 1.5 2 15 1,000,000
7815 K 0.01 4 50,000 0.001 200 3 400 1.5 2 15 2,000,000
7450 J 0.01 6 50,000 0.001 250 3 400 1.5 1.5 12 2,000,000
5664 L 0.001 2 200,000 0.00025 250 8 500 0.4 1.5 50 1,000,000
Custom?Current Monitors

Custom Current Transformer?|?Custom Current Probe?|?Custom Current Transducer
Custom Current Toroid?|?Custom Current Sensor?|?Custom Pulse Current Monitor
Custom High Frequency Current Transformer


Accuracy ±1% or better, initial pulse response for all models, with a high impedance load such as 1 megOhm in parallel with 20 pF. A 50 Ohm termination will reduce the output to half. All models listed below come with a BNC connector except as noted and are to be used with a 50 Ohm coaxial cable. The?current monitor?case is conductive and not insulated. Adequate insulation must be provided on the conductor being monitored. To avoid electrical shock, do not mount or remove the?current monitor?from a live conductor.

STANDARD PACKAGE:
Time Domain Parameters Frequency Domain Parameters

Shape Output
(click to (Volts/ Hole Id.
Model # expand) Amp) (inches) Useable Max. 3dB 3dB I/f
Peak Rise RMS pt. pt. (peak
Curr. Droop Time IT Max. Curr. Low High Amps
(Amps) (%/msec.) (nsec.) (Amp-sec.) (Amps) (Hz) (MHz) /Hz)
5753 D 10 2 50 700 150 0.0005 4 1,000 3 0.004
5834 D 10 2 50 300 350 0.001 4 500 1 0.006
8600 D 10 2 10 35,000 3 0.00005 1 45,000 125 0.00007
2854 2854 1 5 500 40 15 0.04 5 30 20 3.5
7737 A 1 10.75 500 500 40 0.006 35 750 9 0.003
8181 I 1 1 500 80 15 0.002 5 125 20 0.014
8122 D 1 2 500 4 400 0.1 40 6 1 0.6
6027 6027 1 Coaxial 100 200 2 0.0004 2.5 300 200 0.0025
8440 C 1 3.5 500 3 350 0.25 75 4 1 1.5
804 D 0.1 2 5,000 50 20 0.5 75 30 20 3.5
804R D 0.1 2 5,000 12 20 0.6 75 20 20 3.5
8611 8611 0.1 4 5,000 1.5 40 0.5 140 2 10 3
3363 3363 0.1 5 5,000 90 40 1 150 120 10 7.5
3382 3382 0.1 15 1,000 50 80 1.5 250 100 4 10
4285 A 0.1 10.75 5,000 1.5 50 0.4 300 2 7 5.7
5011 5011 0.1 0.25 400 20 5 0.004 10 30 70 0.025
5673 K 0.1 2 5,000 100 9 1 100 150 40 1.1
8365 8365 0.1 0.25 400 7 20 0.004 10 10 20 0.025
8606 A 0.05 10.75 10,000 0.5 75 3 600 1 5 21.2
2811A 2811A 0.02 0.5 1,000 1 500 6 150 1.5 0.7 40
8535 I 0.01 1 25,000 0.3 25 0.6 120 0.5 15 4
4191 4191 0.01 4 50,000 4 60 5 400 6 7 35
4994 D 0.01 2 50,000 3 100 4.5 200 5 4 25
5803 A 0.01 10.75 50,000 4 200 12 1,000 7 2 80
5624 D 0.01 2 20,000 9 25 2 150 12 20 12
7427 K 0.01 2 4,000 2 5 0.2 100 5 70 1.2
5008 E 0.01 0.5 50,000 6 150 2 150 10 3 12
6247A 6247A 0.005 4 100,000 2 350 20 1,500 3 1 120
4427 4427 0.001 3.5 500,000 0.1 300 480 2,800 1 1.2 3,060
5623 D 0.001 2 200,000 1 200 15 400 1.5 2 90
3880 3880 0.001 12 x 2 100,000 0.3 500 150 1,200 0.5 0.7 1,000
2445 2445 0.001 14.5 500,000 1.5 300 40 3,000 3 2 250
4906 4906 0.001 10.75 500,000 1 400 50 2,000 2 1.5 300
7561 B 0.0005 4.75 1,000,000 0.2 2,000 750 3,500 0.15 0.2 3,500

CLAMP-ON:
Time Domain Parameters Frequency Domain Parameters

Shape Output
(click to (Volts/ Hole Id.
Model # expand) Amp) (inches) Useable Max. 3dB 3dB I/f
Peak Rise RMS pt. pt. (peak
Curr. Droop Time IT Max. Curr. Low High Amps
(Amps) (%/msec.) (nsec.) (Amp-sec.) (Amps) (Hz) (MHz) /Hz)
8240 L 2 2 500 n/a 12 n/a n/a 100,000 30 n/a
8546 L 1 2 500 10 600 0.15 50 15 0.5 1.1
8375 L 1 2 500 7,000 4 0.001 10 11,000 100 0.007
8536 8536 1 9 500 750 75 0.007 25 1,250 5 0.04
8579 A 0.1 10.75 5,000 250 50 0.7 120 400 7 4.4
6996 L 0.1 2 5,000 1,040 25 0.5 100 2,000 20 3
8330 L 0.01 2 1,000 100 7 0.3 100 200 50 2.1
5180 5180 0.01 10.75 50,000 0.5 350 2.4 1,200 1 1 45
5769 C 0.05 3.5 10,000 8 100 4 250 12 3.5 25

DOUBLE-SHIELDED:
Time Domain Parameters Frequency Domain Parameters

Shape Output
(click to (Volts/ Hole Id.
Model # expand) Amp) (inches) Useable Max. 3dB 3dB I/f
Peak Rise RMS pt. pt. (peak
Curr. Droop Time IT Max. Curr. Low High Amps
(Amps) (%/msec.) (nsec.) (Amp-sec.) (Amps) (Hz) (MHz) /Hz)
7266 E 1 0.5 500 0.09 10 0.002 5 140 35 0.006
7305 7305 1 1.75 500 0.08 20 0.005 7.5 125 20 0.017
3464 3464 0.1 5000 0.8 20 0.5 100 1 20 1.7
4936 4936 0.1 0.5 5000 0.9 20 0.2 50 1 20 0.6
5007 5007 0.01 1.75? 20000 0.3 20 1 150 0.5 20 3.5
5405 5405 0.01 0.5 50000 6 150 2 150 10 3 12
8574 8574 0.025 20,000 100 100 0.5 100 160 4 3

THIN MODELS:
Time Domain Parameters Frequency Domain Parameters

Shape Output
(click to (Volts/ Hole Id.
Model # expand) Amp) (inches) Useable Max. 3dB 3dB I/f
Peak Rise RMS pt. pt. (peak
Curr. Droop Time IT Max. Curr. Low High Amps
(Amps) (%/msec.) (nsec.) (Amp-sec.) (Amps) (Hz) (MHz) /Hz)
Mar-13 Mar-13 1 0.22 100 400 1.5 0.0002 2 500 250 0.0014
Mar-05 Mar-05 0.1 0.22 300 50 10 0.002 6 50 40 0.013
5974 5974 0.1 0.5 5,000 1 20 0.15 50 2 20 0.6
8500 8500 0.1 2 5,000 4 20 0.1 75 10 20 0.6
8445 8445 0.1 2 5,000 4 20 0.1 75 10 20 0.6
8568 8568 0.01 0.5 25,000 0.4 25 0.4 100 0.8 15 2.5
8532 8532 0.01 1.0? 10,000 0.5 25 0.5 100 0.7 15 3
7765 7765 0.01 2 20,000 1 25 0.25 150 1 20 1
Mar-35 Mar-35 0.005 0.22 5,000 1.5 20 0.04 30 2.5 20 0.25


Accuracy?+1%, initial pulse response for all models, with a high impedance load such as 1 megOhm in parallel with 20 pF. A 50 Ohm termination will reduce the output to half.
Droop:?For a flat top current pulse, the output voltage decays toward zero. Initially, the decay appears linear and the slope is referred to as the droop rate.
Usable Rise Time:?If the 10 to 90% rise time is greater than the specified usable rise time, initial overshoot will be less than 10% of the pulse amplitude.
? = Type N Connector
Capacitive聽Voltage Dividers

聽
Pearson high voltage coaxial capacitive voltage dividers permit measurements up to 500kV when used in high voltage insulating oil. Customized division ratio and calibration for use in air are available. See the table below for model specifications.

Product Selection:
聽 Max Max Voltage
Pulse Pulse Division
Voltage Voltage Ratio Freq Droop Usable
Model # (in oil) (in air) (in oil) Range Rate Rise Capacitance
(1M惟 Load) (per 碌sec) Time (approx)
VD-301 400kV 75kV 聽聽 5000:1 25Hz ~ 3MHz 0.15% 150ns 28pf
VD-305A 300kV 50kV 聽聽 5000:1 30Hz ~ 4MHz 0.02% 150ns 28pf
VD-305A-10,000 300kV 50kV 10,000:1 30Hz ~ 4MHz 0.02% 100ns 18pf
VD-305A-AIR - 50kV 聽聽 5000:1 70Hz ~ 4MHz 0.05% 100ns 聽 8pf
VD-500A 500kV 90kV 10,000:1 15Hz ~ 2MHz 0.01% 200ns 38pf
聽