VOLTCRAFT VC 940 OPERATING MANUAL

Model VC940: OPERATING MANUAL

Chapter Title Page

1 Before You Start

Overview Unpacking Inspection Safety Information Rules For Safe Operation International Electrical Symbols

2 Getting Acquainted

Turning the Meter On Battery Considerations Automatic Power Off Automatic Backlight Off Low Battery Indication The Meter Structure Rotary Switch Functional Buttons The Meter Functions Vs Displays Selecting the Range Understanding the Display Analogue Bar Graph Using MAX MIN

3 Making Measurements

A. Measuring Voltages B. Measuring Currents C. Measuring Resistance D. Testing for Continuity E. Testing Diodes F. Measuring Capacitance G. Measuring Frequency / Duty Cycle H. Measuring Temperature I. 4~20mA loop current as % readout J. Power Measurement

4 Using Stores, Recall and Send Features

Introduction Storing and Clearing Readings Recalling Stored Readings Using Send Sleep Mode

5 Changing the Default Setting

Introduction Selecting Setup Options Saving Setup Options

6 Maintenance

A. General Service B. Replacing the Fuses C. Replacing the Battery

7 Specifications

Safety and Compliances Physical Specifications General Specifications Feature Summary Basic Specifications Detailed Accuracy Specifications A. DC Voltage B. AC Voltage C. DC Current D. AC Current E. Resistance F. Continuity Test G. Diode Test H. Capacitance I. Frequency J. Temperature

Degrees Celsius

Fahrenheit K. 4~20mA loop current L. Power Measurement

Table of Contents

Model VC940: OPERATING MANUAL

Table Title Page

1-1 Unpacking Inspection 1-2 International Electrical Symbols 2-1 Rotary Switch Selections 2-2 Functional Buttons 2-3 Functions Vs Displays 2-4 Display Features 5-1 Setup Selections

List of Tables

Model VC940: OPERATING MANUAL

Figure Title Page 2-1 Meter Structure 2-2 Display Features 3-1 Voltages Measurement 3-2 Currents Measurement 3-3 Resistance Measurement 3-4 Continuity Test 3-5 Diode Test 3-6 Capacitance Measurement 3-7 Frequency / Duty Cycle Measurement 3-8 Temperature Measurement 3-9 Power Measurement 6-1 Fuse Replacement 6-2 Battery Replacement

List of Figures

Model VC940: OPERATING MANUAL

Chapter 1

Before You Start

Overview

This Operating Manual covers information on safety and cautions. Please read the relevant information carefully and observe all the Warnings and Notes strictly.

Warning

To avoid electric shock or personal injury, read the “Safety Information” and “Rules for Safe Operation” carefully before using the Meter.

Digital Multimeter VC940 (hereafter referred to as “the Meter”) is a 39999 counts and 4 3/4 digits with steady operations, fashionable structure and auto ranging instrument. The Meter has analog bar graph, ACV & ACA True RMS and full range overload protection.

The Meter not only can measure AC voltage and current, DC voltage and current, Resistance, Capacitance, Temperature, Frequency, Diodes, Continuity, 4~20mA Loop, Max/Min, Relative Mode but also has Low Battery Display, Store, Recall, Data Hold, Automatic Power Off and power features.

Unpacking Inspection

Open the package case and take out the Meter. Check the items shown on Table 1-1 carefully to see any missing or damaged part:

Item Description Qty

1 English Operating Manual 1 piece 2 Test Lead 1 pair

5 Alligator Clip 1 piece 6 RS232C interface cable 1 piece 7 CD-ROM (Installation Guide &

8 9V Battery (NEDA 1604, 6F22,

9 Power Adaptor 1 piece

In the event you find any missing or damage, please contact your dealer immediately.

Table 1-1. Unpacking Inspection

K-Type (nickel chromium ~ nickel silicon) Point Contact Temperature Probe (It is only suitable for measuring temperature under 230

Computer Interface Software)

006P)

1 piece

Safety Information

This Meter complies with the standards IEC61010 safety measurement requirement: in pollution degree 2, overvoltage category (CAT. III 1000V, CAT. 600V) and double insulation.

CAT. III: Distribution level, fixed installation, with smaller transient overvoltage than CAT. IV CAT.: Primary supply level, overhead lines, cable systems etc.

Use the Meter only as specified in this operating manual, otherwise the protection provided by the Meter may be impaired.

In this manual, a Warning identifies conditions and actions that may pose hazards to the user, or may damage the Meter or the equipment under test.

A Note identifies the information that user should pay attention to.

International electrical symbols used on the Meter and in this Operating Manual are explained on page XX.

Rules For Safe Operation

Warning

To avoid possible electric shock or personal injury, and to avoid possible damage to the Meter or to the equipment under test, adhere to the following rules:

z Before using the Meter inspect the case. Do not use the Meter if it is damaged or the case (or part of the case) is removed. Look for cracks or missing

plastic. Pay attention to the insulation around the connectors.

z Inspect the test leads for damaged insulation or exposed metal. Check the test leads for continuity. Replace damaged test leads with identical model

number or electrical specifications before using the Meter.

z Do not apply more than the rated voltage, as marked on the Meter, between the terminals or between any terminal and grounding. z The rotary switch should be placed in the right position and no any changeover of range shall be made during measurement is conducted to prevent

damage of the Meter.

z When the Meter working at an effective voltage over 60V in DC or 30V rms in AC, special care should be taken for there is danger of electric shock. z Use the proper terminals, function, and range for your measurements. z If the value to be measured is unknown, use the maximum measurement position. z Do not use or store the Meter in an environment of high temperature, humidity, explosive, inflammable and strong magnetic field. The performance of the

Meter may deteriorate after dampened.

z When using the test leads, keep your fingers behind the finger guards. z Disconnect circuit power and discharge all high-voltage capacitors before testing resistance, continuity, diodes. z Before measuring current, check the Meter’s fuses and turn off power to the circuit before connecting the Meter to the circuit.

z Replace the battery as soon as the battery indicator

and personal injury.

z When servicing the Meter, use only the same model number or identical electrical specifications replacement parts. z The internal circuit of the Meter shall not be altered at will to avoid damage of the Meter and any accident. z Soft cloth and mild detergent should be used to clean the surface of the Meter when servicing. No abrasive and solvent should be used to prevent the surface of

the Meter from corrosion, damage and accident.

z The Meter is suitable for indoor use. z Turn the Meter off when it is not in use and take out the battery when not using for a long time. z Constantly check the battery as it may leak when it has been using for some time, replace the battery as soon as leaking appears. A leaking battery will damage

the Meter.

appears. With a low battery, the Meter might produce false readings that can lead to electric shock

International Electrical Symbols

Symbols used on the Meter and in this manual are explained in Table1-2.

Model VC940: OPERATING MANUAL

AC or DC

Grounding

Double Insulated

Warning. Refer to the Operating Manual

Deficiency of Built-In Battery

Conforms to Standards of European Union

Table 1-2. International Electrical Symbols

Model VC940: OPERATING MANUAL

Chapter 2

Getting Acquainted

Turning the Meter On

To turn the Meter on, turn the rotary switch from OFF to any switch setting.

Battery Considerations

The Meter uses one 9V Battery (NEDA 1604, 6F22, 006P). The following paragraphs describe several techniques used to conserve battery power.

Automatic Power Off

The display blanks and the Meter goes into a “sleep” mode if you have not changed the rotary switch position or pressed a button for a set period. While in Sleep mode, pressing the blue button or turning the rotary switch could turn the Meter on. The Meter then returns to the display for the function selected with the rotary switch; all previously activated button features are discarded.

The automatic power off is preset to 30 minutes. From the Setup menu (see Chapter 5), you could specify a time (10 minutes, 20 minutes, 30 minutes or OFF). If you set to OFF, the Meter retains on until you turn the rotary switch to OFF or the battery becomes too weak.

Automatic Backlight Off

Press LIGHT button to turn the backlight on and press LIGHT again to turn it off.

Press SELECT to select the backlight level (low or high). In Setup menu (see Chapter 5), you could specify a time to automatically turn off the backlight (10 seconds, 20 seconds, 30 seconds or OFF). If the period is set to OFF, the backlight feature is disabled.

Low Battery Indication

A constant battery icon ( ) in the upper left corner of the display notifies you that the batteries are low and should be replaced.

Warning

To avoid false readings, which could lead to possible electric shock or personal injury, replace the battery as soon as the battery icon (

The Meter Structure

The Figure 2-1 shows the Meter structure.

1. LCD Display

2. Functional Buttons

3. Rotary Switch

4. Input Terminals

) appears.

Figure 2-1. Meter Structure

Rotary Switch

Turn the Meter on by selecting any measurement function. The Meter presents a standard display for that function. The display may also be influenced by some of the choices made in Setup.

Use the blue button to select any rotary switch alternate function (labeled in blue letters).

When you turn the rotary switch from one function to another, a display for the new function appears. Button choices made in one function do not carry over into another function.

The Table 2-1 described each rotary switch position

Rotary Switch

Position

OFF Turn the Meter off None

Hz 



µA

(4~20mA)

Rotary Switch Function Blue Key Function

DC voltage measurement

AC voltage measurement

DC millivoltage measurement

Resistance measurement

Capacitance measurement

Centigrade temperature measurement AC or DC current measurement (400µA , 4000µA) AC or DC current measurement (40mA , 400mA)

AC or DC current measurement (10A)

Table 2-1. Rotary Switch Selections

None

z Frequency measurement z Frequency signal duty cycle

measurement

z Diode test z Continuity test

None

Fahrenheit temperature measurement

Toggle between AC or DC current

Toggle between AC or DC current 4~20mA loop current as % reading

Toggle between AC or DC current

Model VC940: OPERATING MANUAL

Functional Buttons

The buttons activate features that augment the function selected with the rotary switch. The buttons are shown in Table 2-2.

Press the button once to access the main feature (e.g. STORE).

To access the first additional feature of the button (e.g. RECALL), press and hold the button for over 1 second to access this additional feature. This additional feature appears right above or on the left hand side of the appropriate keys.

To access the second additional feature of the button (e.g. second additional feature appears on the right hand side above the appropriate keys.

The RANGE and EXIT buttons has only one additional feature.

Button Description Access Method

Range feature: Exit AUTO and enter MANUAL ranging. In MANUAL, select next input range. EXIT to return to AUTO. AUTO is default.

), press once the button again while the Meter has already entered the first additional feature (e.g. RECALL). The

Table 2-2. Functional Buttons

Press the button once.

Yellow Button

Setup feature: Access Setup selections, the display shows “SET”.

Press and hold the button for more

than 1 second In the Setup mode, each press of SETUP button steps to the next Selection Store feature: Store the current measurement value. Press EXIT to exit the

Press the button

once. Store feature. Recall feature: Recall the stored value. Press EXIT to exit the Recall

Press and hold the button for over 1

second feature. Setup feature: In Setup, press to select OFF at the selection of HIGH and

Press the button

once after entering Setup mode. LOW Hold feature:

Press the button once. Press HOLD to freeze the displayed value. Press EXIT to release the display. Peak Hold feature: Press to access Peak Hold feature, the primary display

Press and hold the button for over 1

second. shows PEAK HOLD. Press EXIT to exit. z In Setup, each press to select the digit you want to

edit.

Press the button once after entering

Setup or Recall or Store mode.

z In Recall, press to enable SEND feature z In Store, press to toggle between clearing all the

stored reading or start storing reading from the current index number.

Press to exit certain button functions Press the button once.

Press to turn the backlight on. It is possible to toggle between 1

and the 2nd backlight and Exit the feature by

Press and hold the button for over 1

second. pressing the button. After exiting the light feature, it is necessary to press and hold the button for over 1 second to turn the backlight on again.

Press to display max, min and average values.

Press the button once.

Press EXIT to stop and return to current measurement mode.

Press to output the data, AUTO mode switch off. The primary display shows “SEND”.

Press and hold

the button for over 1 second.

Press EXIT to exit.

In Setup, each press to decrement an Option. In Recall, each press to go back to the previous stored

Press the button once after entering

SEND mode. reading.

In Store, each press to decrease a second on the storing interval. Press EXIT to exit

Press to enter relative mode, the primary display shows .

Press the button once.

The left secondary display shows the present measurement value. The right secondary display shows the stored value. The primary display shows the present measurement value minus the stored value. Press EXIT to exit relative mode.

In Setup, each press to increment an Option. In Recall, each press to recall the next stored reading.

Press and hold the button for over 1

second. In Store, each press to increase a second on the storing interval. When it is at AC measurement mode, press the button to

Press the button once display AC+DC True RMS value in the primary display and the left secondary display “AC+DC”.

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