Yokogawa 30032A Leakage Clamp-on Tester with a Sharp Low Pass Filter Function

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• Can measure leakage currents of 1 mA, which is useful for checking the insulation of low-voltage circuits and electrical components.
• Can measure a broad range of currents from leakage currents (at a resolution of 0.001 mA) to load currents up to 60 A.
• Typical influence (on the current value of an adjacent cable) from an external magnetic field is 0.0005%.
• Durability of clamp: More than 50,000 opening/closing events
• Twice the tensional strength of Yokogawa M&C's earlier model clamps
• The clamp lever is lengthened by 30%, enabling smooth opening/closing of the clamp even for thick cables of 40mm in diameter.
• Approved for conformity to safety standards EN 61010-1 and EN 61010-2-032 (CAT III 300V, pollution degree2)

*Waveforms obtained when measuring a distribution board of a Yokogawa Meters & Instruments Corporation office

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Harmonic Filter Function (Only Available in the 30032A)

1. What is a Harmonic?

Harmonic refers to sinusoidal quantity having a frequency that is an integral multiple of the fundamental frequency (for example, the commercial frequency). When a harmonic is superimposed on the fundamental frequency, the waveform is distorted.
 

2. Why is it Necessary to Accurately Measure the Leakage Current of the Fundamental Frequency (Commercial Frequency)?

One problem when measuring the leakage current to check the isolation of electrical circuits in power distribution equipment is that the electrical isolation cannot be correctly understood due to the influence of a harmonic current. That is, the leakage current flowing from the electrical circuit to ground is very small so that, in order to check the isolation of electrical circuits by means of the leakage current, it is necessary to remove the harmonic component of the leak current and measure only the current of the fundamental frequency (commercial frequency).
 

3. The 30032A Employs a Harmonic Filter

Conventional leakage clamp-on testers could not sufficiently remove harmonic current components so measured leakage current values were often larger than the specified value due to the influence of a harmonic current. In this case, retesting with an insulation tester was required, resulting in increased effort and cost for the test. Under these circumstances, Yokogawa Meters & Instruments Corporation has developed the leakage clamp-on tester 30032A, which employs a high-performance harmonic filter that can accurately measure just the fundamental frequency component of the leakage current.

Characteristics of Harmonic Filter

1. Filter Characteristic of the 30032A

When the frequency is more than 60 Hz, the sharp filter removes the harmonic component, leaving the fundamental frequency.
For example, the level of 100 Hz is attenated to approx. 1%.
(Reference Figure 1: Harmonic Filter Characteristic 1)

Figure 1: Harmonic Filter Characteristic 1

Figure 1: Harmonic Filter Characteristic 1

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2. Filter Comparison (between the On and Off States)

This is the filter characteristic in the On and Off states.
(Reference Figure 2: Harmonic Filter Characteristic 2)

(reference) When the filter is in the On or Off state Amplitude ratios in the range between the fundamental frequency and the third frequency
(Fundamental frequency: 60 Hz)

Figure 2: Harmonic Filter Characteristic 2

Figure 2: Harmonic Filter Characteristic 2

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Measurement method of leakage current		Measurement location of leakage current	A: Measurement of the grounding wire for the transformer class B grounding work
			B: Measurement of the electrical circuit
			C: Measurement of the grounding wire of electrical equipment

(1) 3-phase 4-wire electrical circuit	(2) Single-phase 3-wire electrical circuit
3-phase 4-wire electrical circuit ×	Single-phase 3-wire electrical circuit ×
• In the case of load current	• Example of load measurement with the CL Series
In the case of load current ×	Example of load measurement with the CL Series ×