Zinc Oxide Arrester Tester
Darui Electric recommends:
I. LYYHX6000 Wireless Zinc Oxide Arrester Live Tester Features
1) This instrument uses a large-screen LCD display, full Chinese menu operation, easy to use.
2) High-precision sampling and processing circuits, advanced Fourier harmonic analysis technology, ensuring more reliable data.
3) The instrument uses a unique high-speed magnetic isolation digital sensor to directly collect input voltage and current signals, ensuring
data reliability and safety.
4) LYYHX6000 Wireless Zinc Oxide Arrester Live Tester can use electric field induction or wireless transmission methods to replace PT secondary wiring.
5) This instrument can directly measure resistive current without connecting to PT secondary.
6) This instrument has six test methods, providing testers with a wide range of options. (PT secondary method, induction method, wireless transmission method, single current synchronization method, PT secondary synchronization method, wireless synchronization method)
7) This instrument can measure three phases simultaneously with automatic compensation. Very convenient to use.
8) LYYHX6000 has rechargeable battery, calendar clock, micro printer, can store 120 sets of measurement data;
LYYHX6000 Main Technical Parameters
Total current measurement range: 0~10mA RMS
Accuracy: ±(reading×5% 5uA)
Resistive current fundamental measurement accuracy (wired, excluding inter-phase interference): ±(reading×5% 5uA)
Current harmonic measurement accuracy: ±(reading×10% 10uA)
Current channel input resistance: ≤2Ω
Reference voltage input range: 25V~250V RMS
Accuracy: ±(reading×5% 0.5V)
Voltage harmonic measurement accuracy: ±(reading×10%)
Reference voltage channel input resistance: ≥1800kΩ
Battery continuous working time: more than 8 hours
Battery charging time: more than 6 hours
AC charging: AC 220V 10%, 50Hz 1%
Instrument dimensions: 32cm×27.5cm×14cm
Instrument weight: 5kg (excluding cable box)
III. LYYHX6000 Operation Modes
1. The instrument inputs PT secondary voltage as reference signal, and simultaneously inputs MOA current signal. After Fourier transform, the voltage fundamental U1, current fundamental peak Ix1p, and current-voltage angle Φ can be obtained. Therefore, the component in phase with voltage is the resistive current fundamental peak (Ir1p), and the orthogonal component is the capacitive current fundamental peak (Ic1p):
Ir1p=Ix1pCOSΦ Ic1p=Ix1pSINΦ
Considering that δ=90°—Φ is equivalent to the dielectric loss angle, directly using Φ to evaluate MOA is also very simple: when there is no "inter-phase interference", Φ is mostly between 81°~86°. According to the requirement that "resistive current cannot exceed 25% of total current", Φ cannot be less than 75.5°. Refer to the table below for segmented evaluation of MOA performance:
Performance <75° 75°~77° 78°~80° 81°~83° 84°~89° >89°
Φ Poor Bad Medium Good Excellent Interference
Actually, attention should be paid when Φ<80°.
Grounding:
Connect the ground wire before measurement, and disconnect the ground wire last after measurement! If the grounding point has paint or rust, it must be cleaned.
Reference Voltage
Insert one end of the reference voltage signal line into the reference voltage socket, and connect the other end to the PT secondary low-voltage output of the phase under test: the small black clip connects to the neutral point (x), and the small red clip connects to the phase voltage under test (a/b/c). For external voltage method, connect to the measurement winding of the step-up transformer. If the PT is far away, an extension cable can be used.
Current Signal
First insert the leakage current signal line plug into the instrument, then clip the other end (or hang it via an insulating rod) to the upper end of the MOA discharge counter of the phase under test. In the laboratory, the MOA without discharge counter can be placed on an insulating board, and the current signal can be taken from the lower end of the MOA. Extension cables cannot be used for current signals.
The wiring diagram is as follows: (Figure 2)
2. (Induction) Mode (customized upon customer request):
An electric field induction sensor is set on the MOA base. Its induced current leads the electric field strength (bus voltage) by 90°. After integration, it is in phase with the electric field strength or bus voltage, so the signal from the electric field induction sensor can be used as a measurement reference. The instrument inputs the electric field induction sensor signal and simultaneously inputs the MOA current signal. After Fourier transform, the electric field fundamental E1, current fundamental peak Ix1p, and current-electric field angle Φ can be obtained. The component in phase with the electric field is the resistive current fundamental peak (Ir1p), and the orthogonal component is the capacitive current fundamental peak (Ic1p).
Using B-phase induction signal as reference
Because the electric field influence of A/C side phases on the B-phase base cancels out, the induction plate should be set at a position on the B-phase MOA base that is symmetrical to the A/C phases, to obtain correct phase information for B phase. The electric field on the A/C phase MOA base is affected by B phase, so do not set the induction plate on the A/C phase MOA base.
The wiring diagram is as follows: (Figure 3)
3.
The instrument uses the received wireless signal as reference voltage, and simultaneously inputs the MOA current signal. After Fourier transform, the voltage fundamental U1, current fundamental peak Ix1p, and current-voltage angle Φ can be obtained. Therefore, the component in phase with voltage is the resistive current fundamental peak (Ir1p), and the orthogonal component is the capacitive current fundamental peak (Ic1p):
Ir1p=Ix1pCOSΦ Ic1p=Ix1pSINΦ
Considering that δ=90°—Φ is equivalent to the dielectric loss angle, directly using Φ to evaluate MOA is also very simple: when there is no "inter-phase interference", Φ is mostly between 81°~86°. According to the requirement that "resistive current cannot exceed 25% of total current", Φ cannot be less than 75.5°. Refer to the table below for segmented evaluation of MOA performance:
Performance <75° 75°~77° 78°~80° 81°~83° 84°~89° >89°
Φ Poor Bad Medium Good Excellent Interference
Actually, attention should be paid when Φ<80°.
Grounding:
Connect the ground wire before measurement, and disconnect the ground wire last after measurement! If the grounding point has paint or rust, it must be cleaned.
Wireless Signal:
Insert one end of the reference voltage signal line into the reference voltage socket of the signal transmitter, and connect the other end to the PT secondary low-voltage output of the phase under test: the small black clip connects to the neutral point (x), and the small red clip connects to the phase voltage under test (a/b/c). For external voltage method, connect to the measurement winding of the step-up transformer. If the PT is far away, an extension cable can be used. Turn on the power switch of the signal transmitter, and you will see the transmission signal indicator light flashing.
Current Signal
First insert the leakage current signal line plug into the instrument, then clip the other end (or hang it via an insulating rod) to the upper end of the MOA discharge counter of the phase under test. In the laboratory, the MOA without discharge counter can be placed on an insulating board, and the current signal can be taken from the lower end of the MOA. Extension cables cannot be used for current signals.
The wiring diagram is as follows:
In (Wireless Transmission) mode and (Wireless Transmission Synchronous Display) mode, the antenna needs to be screwed on first. When screwing the antenna, pay attention to the force, do not overtighten. Both the host and signal transmitter antennas must be screwed on.
If the signal reception is poor, the signal transmitter should be placed in a high position.
4. (Single Current Synchronous Display) Mode:
Only one current wire is needed. Once the current signal is obtained, the total current and resistive current can be measured.
Current Signal
First insert the leakage current signal line plug into the instrument, then clip the other end (or hang it via an insulating rod) to the upper end of the MOA discharge counter of the phase under test. In the laboratory, the MOA without discharge counter can be placed on an insulating board, and the current signal can be taken from the lower end of the MOA. Extension cables cannot be used for current signals.
The wiring diagram is as follows: (Figure 4)
5. Note: In (Synchronous Display) mode, only IB, the green current channel, is applicable.
Also, in the test state, only the "OK" and "Decrease" keys are applicable, and they need to be pressed and held to take effect.
"OK" key prints data.
"Decrease" key returns to the initial state.
IV. Three-Phase Simultaneous Measurement
Grounding:
Connect the ground wire before measurement, and disconnect the ground wire last after measurement! If the grounding point has paint or rust, it must be cleaned.
Reference Voltage:
Insert one end of the reference voltage signal line into the reference voltage socket, and connect the other end to the B-phase PT secondary low-voltage output.
Current Signal:
First insert the leakage current signal line plug into the instrument, then clip the four clips at the other end (or hang them via insulating rods) to the upper ends of the A, B, C phase MOA discharge counters and the ground terminal. Extension cables cannot be used for current signals.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
