HZJF-9041D 4-Channel Partial Discharge Test Equipment

1. Brief introduction

According to the standard of IEC and advanced theory of partial discharge,

HZJF-9041D fit for many products, it has high sensitivity, high S/N, a large screen which has clear testing wave displaying, high frequency ellipse scan (the power is less than 1VA)., auxiliary zero marking system. The discharge meter has pointer/digital display and linearity /digital function. The amplifier has large dynamic range, 9 kinds of frequency bａnd combinations.

HZJF-9041D is a powerful tool for developing new high voltage electric products and improving the quality of the products. It is also an efficient testing device to judge the work condition of equipments on the work field. This device is used together with model JZF-9 or JZF-10 calibrator.

2. Main specification

2.1 Measure channel：4-channel

2.2 Capacitance range of measured piece 6pF~250uF

2.3 Measuring sensitivity and Max. current（see table 1）

Table 1.

2.4 Time base of ellipse scan

(1) Frequency 50 /60(inner), 100, 150, 200, 400Hz

(2) Turn: 30º per grade, total 360º

(3) Display ways: ellipse——expand——beeline

(4) The high frequency time base ellipse can be adjusted to normal state by input voltage (10-250V), and the power is less than 1 VA. Auto-protecting function when overload

2.5 Displaying Unit

A rectangle oscillograph tube (124×104mm²), which has brightness and focus knobs.

2.6 Amplifier

(1) On low frequency 3dB, fL: 10, 20, 40 KHz optional

(2) On high frequency 3dB, fH: 80, 200, 300 KHz optional

(3) Gain adjusting: 6 grades of gross adjustment. Gain difference between grades is 20±1dB, fine adjusting range >20dB

(4) Asymmetry of plus and minus pulse responding <>

2.7 Time window

(1) Adjustable window width, 15º~150º on 50/60Hz

(2) Rotatable window position, 0º~170º

(3) Two windows can on/off respectively or simultaneously

2.8 Pulse peak meter

(1) Pointer meter with linear graduation. 0-100

(2) Pointer meter with logarithm graduation. 0-10-100

(3) Digital meter with 3.5 bits LED digital display, 0-100

(4) Discharge magnitude linear deviation: <>

2.9 Zero mark system

(1) Made by inner zero mark generator, it can change polarity and rotate 0-180º, so it can correspond with the true zero mark, which is made by high voltage resistor.

(2) The zero mark is corresponded with all ellipse scan frequency.

2.10 Power

AC Power: 230/400V; 60Hz; 3Phase

2.11 Work environment

Vicinity medium temperature is -5 ºC ~+45ºC

Air relative humidity is no more than 85%

3.Working Principle

When measured piece Cx has partial discharge under testing voltage, the circuit will have pulse current, which get by the input unit. The pulse signal is amplified by front amplifier and the frequency bａnd is chose by filter amplifier, then been amplified to needed amplitude by the main amplifier. The pulse signal will be displayed on oscillograph screen. The pulse value is also sent to the pulse peak meter and displayed immediately. The time window unit chooses a working period of the pulse peak meter during each cycle of testing voltage, and it increases the brightness of the relevant displaying area in this time. In this way, it can avoid the disturbing of fixed phase.

Input discharge volume to the measured piece Cx through JZF series PD external calibrator, adjust the fine adjusting knob till the displayed value is equal to the discharge volume, the discharge can be read directly and conveniently on the meter without counting.

The testing voltmeter will have an over zero mark signal of testing voltage through the voltmeter resistance R, and the zero mark pulse will be displayed on oscillograph screen. The testing voltage can be displayed on KV meter.