HT instruments HT9012 User Manual

ENGLISH

User manual

HT9012

Contents:

1 SAFETY PRECAUTIONS AND PROCEDURES ..........................................................2

1.1 Preliminary ........................................................................................................................ 2

1.2 Before use......................................................................................................................... 3

1.3 After use............................................................................................................................ 3

1.4 Measuring (overvoltage) categories definitions................................................................. 3

2 GENERAL DESCRIPTION ...........................................................................................4

2.1 TRMS and Mean Value measuring instruments................................................................ 4

2.2 True Root Mean Square value and crest factor definitions ............................................... 4

3 PREPARATION FOR USE ...........................................................................................5

3.1 Initial.................................................................................................................................. 5

3.2 Power supply..................................................................................................................... 5

3.3 Calibration ......................................................................................................................... 5

3.4 Storage.............................................................................................................................. 5

4 OPERATING INSTRUCTIONS.....................................................................................6

4.1 Instrument description....................................................................................................... 6

4.1.1 Commands description............................................................................................................... 6

4.1.2 Alignment marks ......................................................................................................................... 6

4.2 Function key description.................................................................................................... 7

4.2.1 HOLD key ................................................................................................................................... 7

4.2.2 key ........................................................................................................................................ 7

4.2.3 RANGE key ................................................................................................................................ 7

4.2.4 MAX key ..................................................................................................................................... 7

4.2.5 MODE key .................................................................................................................................. 7

4.3 Functions of rotary switch description ............................................................................... 8

4.3.1 DC Voltage measurement ..........................................................................................................8

4.3.2 AC Voltage measurement ..........................................................................................................9

4.3.3 AC Current measurement......................................................................................................... 10

4.3.4 Resistance measurement......................................................................................................... 11

4.3.5 Continuity test and Diode test................................................................................................... 12

5 MAINTENANCE .........................................................................................................13

5.1 General informations....................................................................................................... 13

5.2 Battery replacement ........................................................................................................ 13

5.3 Cleaning .......................................................................................................................... 13

5.4 End of life ........................................................................................................................ 13

6 TECHNICAL SPECIFICATIONS ................................................................................14

6.1 Characteristics.................................................................................................................14

6.1.1 Safety........................................................................................................................................ 15

6.1.2 General data ............................................................................................................................. 15

6.2 Environmental conditions ................................................................................................ 15

6.2.1 Climatic conditions.................................................................................................................... 15

6.3 Accessories.....................................................................................................................15

6.3.1 Standard accessories ............................................................................................................... 15

7 SERVICE....................................................................................................................16

7.1 Warranty conditions......................................................................................................... 16

7.2 Service ............................................................................................................................ 16

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HT9012

1 SAFETY PRECAUTIONS AND PROCEDURES

This clamp complies with IEC/EN61010-1. For your own safety and in order to avoid damaging the instrument, you’re recommended to keep to the instructions contained in this

manual and read carefully all the notes preceded by the symbol .

Take extreme care for the following conditions while measuring:

• Do not measure voltage or current in humid or wet environment

• Do not use the meter in presence of explosive gas (material), combustible gas

(material), steam or dust

• Insulate yourself from the object to be tested

• Do not touch exposed metal (conductive) parts such as test lead ends, sockets, fixing

objects, circuits, etc

• If you detect anomalies of testing end (metal part) and attachment of the meter such as

breakages, deformations, foreign substances, no display, etc., do not take any measurement

• Measuring voltage over 20V as it might cause human body electricity conduction

The followings symbols are used:

Caution: refer to the instruction manual. An incorrect use may damage the tester or its components

High Voltage ranger: electrical shock risk

Double insulated instrument

AC Voltage or Current

DC Voltage

Ground reference

1.1 PRELIMINARY

• This apparatus has been designed for use in an environment of pollution degree 2.

Indoor use

• It measures CURRENT and VOLTAGE on CAT IV 600V to ground plants. For

overvoltage categories please see § 1.4

• You must comply with the usual safety regulations aimed at trotecting you against the

dangerous electric current and protecting the instrument against an incorrect operation

• Only the leads supplied with the instrument guarantee compliance with the safety

standard. They must be in good conditions and they must be replaced, if necessary, with an identical model

• Do not test or connect to any circuit whose voltage or current exceeds the specified

overload protection

• Do not perform any test at environmental conditions exceeding the limits indicated

• Make sure that the battery are installed correctly

• Before connecting the test probes to the installation, check that the function selector is

positioned on the required measurement

• Make sure that the LCD and the rotate switch show the same as the function desired

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HT9012

1.2 BEFORE USE

Always keep to the instructions contained in this manual:

CAUTION

Non compliance with the warnings and/or the instructions may damage the tester and/or its components or injure the operator.

• Before changing the switch’s position, take off the clamp jaw from the tested conductor

or the electrical circuit in order to avoid any accident

• When the clamp is connected to the circuits to be tested, never touch unused terminals

• When testing resistors, do not add voltage. Although there is a protection circuit,

excessive voltage would cause malfunctioning

• Before measuring current, remove the voltage-resistance test leads

• When measuring current, any strong current near or close to the clamp jaw will affect

the accuracy

• When measuring current, always put the tested conductor in the middle of the clamp

jaw in order to obtain a more accurate reading

• If the reading value or the sign indication remains unchanged during the measurement,

check if the HOLD function is active

1.3 AFTER USE

• Once the measurements are completed, turn the rotary switch to OFF

• If you expect not to use the clamp for a long time, remove the battery

1.4 MEASURING (OVERVOLTAGE) CATEGORIES DEFINITIONS

The norm IEC/EN61010-1: Safety requirements for electrical equipment for measurement, control and laboratory use, Part 1: General requirements, defines what measuring category, usually called overvoltage category, is. On § 6.7.4: Measuring circuits, it says:

(OMISSIS)

circuits are divided into the following measurement categories:

• Measurement category IV is for measurements performed at the source of the low-

voltage installation

Examples are electricity meters and measurements on primary overcurrent protection devices and ripple control units

• Measurement category III is for measurements performed in the building installation

Examples are measurements on distribution boards, circuit breakers, wiring, including cables, bus-bars, junction boxes, switches, socket-outlets in the fixed installation, and equipment for industrial use and some other equipment, for example, stationary motors with permanent connection to fixed installation

• Measurement category II is for measurements performed on circuits directly

connected to the low voltage installation

Examples are measurements on household appliances, portable tools and similar equipment

• Measurement category I is for measurements performed on circuits not directly

connected to MAINS

Examples are measurements on circuits not derived from MAINS, and specially protected (internal) MAINS-derived circuits. In the latter case, transient stresses are variable; for that reason, the norm requires that the transient withstand capability of the equipment is made known to the user

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HT9012

2 GENERAL DESCRIPTION

HT9012 meter can performs the herewith measurements:

• DC and AC voltage

• Detection of AC voltage without contact

• AC current

• Resistance and test continuity

• Diode test

Each parameter can be selected by rotating the 8-positions switch included OFF position.

To abilitate the hold function the HOLD key is available. There are also key to activate/desactivate the display backlight, the RANGE key for manual selction of measurement ranges, the MAX key for maximum value measurement of some parameters and the MODE key for the selection of different features common at the same position of

selector rotation. The selected quantity appears on a high-contrast liquid crystal display with indication of measurement units and functions. The instrument disposes of an Auto Power Off function consisting in an automatic switching off 15 minutes after last selector rotation.

2.1 TRMS AND MEAN VALUE MEASURING INSTRUMENTS

Safety testers for alternate quantities are divided into two big families:

• MEAN VALUE instruments: instruments which measure only the value of the wave at

the fundamental frequency (50 or 60 Hz)

• TRUE ROOT MEAN SQUARE instruments, also defined as TRMS: instruments which

measure the true root mean square value of the quantity under test In presence of a perfectly sinusoidal wave, both families provide identical results. In presence of distorted waves, instead, the readings are different. Mean value instruments provide only the value of the fundamental wave while True RMS instruments provide the value of the entire wave, including harmonics (within the passband of the instrument). Accordingly, if the same quantity is measured with both kinds of instruments, the measured values are identical only if the wave is purely sinusoidal. Should it be distorted, True RMS instruments provide higher values than medium value instruments.

2.2 TRUE ROOT MEAN SQUARE VALUE AND CREST FACTOR DEFINITIONS

The current effective value is defined as follows: “In an interval of time equivalent to a period, an alternate current with effective value having an intensity of 1A, by passing on a resistor, disperses the same energy which would be dispersed in the same period of time by a direct current having an intensity of 1A”. From this definition comes the numerical

+Tt

expression: G=

The Crest Factor is defined as the ratio between the Peak Value of a signal and its

effective value: CF (G)=

for a purely sinusoidal wave it’s worth 2=1.41. In presence of distortions the Crest Factor assumes higher values as long as the wave distortion is higher.

dttg

)(

∫

The effective value is indicated as RMS (root mean square).

. This value varies according to the waveform of the signal,

RMS

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HT9012

3 PREPARATION FOR USE

3.1 INITIAL

The tester has been checked from a mechanical and electrical point of view before shipment.

Every care has been taken to make sure that the instrument reaches you in perfect conditions.

However, it’s advisable to make a rapid check in order to detect eventual damages which may have occurred in transit. Should this be the case, enter immediately the usual claims with the carrier.

Make sure that all the accessories listed in § 6.3.1 are contained in the package. In case of discrepancies contact the dealer.

In case of returning of the tester please keep to the instructions given in § 7.

3.2 POWER SUPPLY

The instrument is battery supplied. One battery 9V IEC 1604 NEDA 6F22 are included in the package. When battery is low, the symbol “ ” appears on the display. Replace it

immediately, following the instructions given in § 5.2. The instrument disposes of the Auto Power OFF function (not disable) consisting in an automatic switching off 15 minutes of idleness.

3.3 CALIBRATION

The tester complies with the technical features listed in this manual. Its performances are guaranteed for one year.

3.4 STORAGE

In order to guarantee the accuracy of the measurements, after a period of storage in extreme environmental condition, wait for the necessary time so that the tester returns to normal measuring conditions (see environmental specifications, § 6.2.1).

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