Thurlby Thandar Instruments AC1000 User Manual [en, de, fr, it]

AC1000

Low Distortion Power Source

INSTRUCTION MANUAL

Introduction

The AC1000 is an innovative, low cost, pure power source designed specifically for use with a harmonics analyser such as the TTi HA1600, permitting compliance quality measurements to EN61000–3–2.

The AC supply available at a standard wall socket is usually distorted. This comes about because of nonlinear loads (non–resistive loads) on the AC supply such as transformers, fluorescent lights, switched–mode power supplies etc. In a typical load there are rectifiers and capacitors that cause current to be drawn from the supply only near the peak of the waveform. The effect of this is to flatten off the top of the sine wave causing significant distortion.

In a typical factory environment this distortion can be so significant that it is easily visible using an oscilloscope.

EMC legislation (EN61000–3–2) has made mandatory the measurement of harmonic current produced by electronic equipment, and requires that the source supply provides a pure voltage waveform to the equipment under test. The harmonic currents can differ significantly when a pure source is used so it is important that any testing is performed with a device such as the AC1000.

Compact and portable the AC 1000 is rated up to 1000 V·A for 230 V operation and will supply 1000 V·A at 230 V input at up to 35°C ambient. In contrast to other techniques which use a passive filtering approach, the AC1000 uses an innovative technique which actively corrects the AC supply to produce a harmonically pure output.

The AC1000 is also very useful for stress testing power supplies in electronic equipment. The use of a harmonically pure, distortion free device – such as the AC1000 – is essential to fully stress and evaluate the power supply under test.

Specification 2 Safety 4 EMC 5 Installation 6 Operation 7 Maintenance 8 Instructions en Francais 9 Bedienungsanleitung auf Deutsch 13 Istruzioni in Italiano 17 Instrucciones en Español 21

Specification

Input Voltage: Factory set to 230V, 115V or 100V; 50Hz or 60Hz.

Installation Category II.

Supply Tolerances: 230V setting : 198V – 253V

115V setting: 99V – 127V 100V setting: 90V – 110V

50Hz setting: ± 0·5Hz

60Hz setting: ± 0·6Hz

Output Voltage: Tracks the amplitude of the fundamental of the input voltage. A variable

voltage input may be used to adjust the output voltage to within the limits specified by EN61000–3–2.

Output Distortion: Dependent on the purity of the input but will generally meet the requirements

of EN61000–3–2. Output Current: Maximum continuous output current is 4·4A. Output Power: Maximum output power is input voltage x 4·4 VA Input Connection: IEC connector; front panel switch. Output Connection: U.K., Schuko, or other national outlet sockets. Load power switch can be set

to DIRECT or CORRECTED for ‘A–B’ comparisons. Protection: Thermal trip automatically diverts load to a DIRECT connection in the event of

thermal overload. Operating Range: Storage Range: Environmental: Indoor use at altitudes to 2000m, Pollution Degree 2. Safety: Complies with EN61010–1 EMC: Complies with EN50081-1 and EN50082-1. Size: 307 x 105 x 225 mm (W x H x D) Weight: 5 kg.

+5°C to +35°C at full rated output; 20% to 80% RH (non-condensing).

–40°C to +70°C

f) EN61000-4-6 (2009) Conducted RF

EC Declaration of Conformi ty

We Thurlby Thandar Instruments Ltd Glebe Road Huntingdon Cambridgeshire PE29 7DR England

declare that the

AC1000 Low Distortion Power Source

meets the intent of the EMC Directive 2004/108/EC and the Low Voltage Directive 2006/95/EC. Compliance was demonstrated by conformance to the following specifications which have been listed in the Official Journal of the European Communities.

EMC

Emissions: a) EN61326-1 (2006) Radiated, Class B

b) EN61326-1 (2006) Conducted, Class B c) EN61326-1 (2006) Har monic s, referring to EN61000-3-2 (2006)

Immunity: EN61326-1 (2006) Immunity T able 1, Performance B, referring to:

a) EN61000-4-2 (2009) Electrostatic Discharge b) EN61000-4-3 (2006) Electromagnetic Field c) EN61000-4-11 (2004) Voltage Interrupt d) EN61000-4-4 (2004) Fast Transient e) EN61000-4-5 (2006) Surge

Safety EN61010-1 (1993) Installation Category II, Pollution Degree 2.

CHRIS WILDING TECHNICAL DIRECTOR 2 January 2013

incorrect operation may damage the instrument.

Safety

This power supply is a Safety Class I instrument according to IEC classification and has been designed to meet the requirements of EN61010-1 (Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use). It is an Installation Category II instrument intended for operation from a normal single phase supply.

This instrument has been tested in accordance with EN61010-1 and has been supplied in a safe condition. This instruction manual contains some information and warnings which have to be followed by the user to ensure safe operation and to retain the instrument in a safe condition.

This instrument has been designed for indoor use in a Pollution Degree 2 environment in the temperature range 5°C to 35°C, 20% - 80% RH (non-condensing). It may occasionally be subjected to temperatures between +5° and -10°C without degradation of its safety. Do not operate while condensation is present.

Use of this instrument in a manner not specified by these instructions may impair the safety protection provided. Do not operate the instrument outside its rated supply voltages or environmental range. In particular excessive moisture may impair safety.

WARNING! THIS INSTRUMENT MUST BE EARTHED

Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous. Intentional interruption is prohibited. The protective action must not be negated by the use of an extension cord without a protective conductor.

When the instrument is connected to its supply, terminals may be live and opening the covers or removal of parts (except those to which access can be gained by hand) is likely to expose live parts. The apparatus shall be disconnected from all voltage sources before it is opened for any adjustment, replacement, maintenance or repair. Capacitors inside the power supply may still be charged even if the power supply has been disconnected from all voltage sources but will be safely discharged about 1 minute after switching off power.

Any adjustment, maintenance and repair of the opened instrument under voltage shall be avoided as far as possible and, if inevitable, shall be carried out only by a skilled person who is aware of the hazard involved.

If the instrument is clearly defective, has been subject to mechanical damage, excessive moisture or chemical corrosion the safety protection may be impaired and the apparatus should be withdrawn from use and returned for checking and repair.

Make sure that only fuses with the required rated current and of the specified type are used for replacement. The use of makeshift fuses and the short-circuiting of fuse holders is prohibited.

Do not wet the instrument when cleaning it. The following symbols are used on the instrument and in this manual:-

mains supply OFF.

mains supply ON.

alternating current (ac)

Caution – refer to the accompanying documentation;

This instrument has been designed to meet the requirements of the EMC Directive 2004/108/EC. Compliance was demonstrated by meeting the test limits of the following standards:

Emissions

EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use. Test limits used were:

a) Radiated : Class B b) Conducted : Class B c) Harm onics: EN61000-3-2 (2006) Class A; the instrument is Class A by product category. Note that emissions from the AC1000 are within specification when fully loaded with a compliant

load, e.g. a pure resistance. If the load is non-compliant, emissions from the AC1000 will similarly be non-compliant.

Immunity

EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use.

EMC

Test methods, limits and performance achieved were: a) EN61000-4-2 (2009) Electrostatic Discharge : 4kV air, 4kV contact, Performance A. b) EN61000-4-3 (2006) Electromagnetic Field, 3V/m, 80% AM at 1kHz, Performance B. c) EN61000-4-11 (2004) Voltage Interrupt, 1 cycle, 100%, Performance B. d) EN61000-4-4 (2004) Fast Transient, 1kV peak (AC line), 0.5kV peak (DC Outputs),

e) EN61000-4-5 (2006) Surge, 0.5kV (line to line), 1kV (line to ground), Performance A. f) EN61000-4-6 (2009) Conducted RF, 3V, 80% AM at 1kHz (AC line only; DC Output

According to EN61326 the definitions of performance criteria are:

Performance criterion A: ‘During test normal performance within the specification limits.’ Performance criterion B: ‘During test, temporary degradation, or loss of function or

performance which is self-recovering’. Performance criterion C: ‘During test, temporary degradation, or loss of function or

performance which requires operator intervention or system reset occurs.’

Cautions

Performance B.

connections <3m not tested), Performance A.

To ensure continued compliance with the EMC directive the following precautions should be observed:

a) after opening the case for any reason ensure that all signal and ground

connections are remade correctly before replacing the cover. Always ensure all case screws are correctly refitted and tightened.

b) In the event of part replacement becoming necessary, only use components of an

identical type, see the Service Manual.

Mains Operating Voltage and Frequency

Check that the instrument operating voltage and frequency marked on the rear panel are correct for the local supply; these are factory set and cannot be changed by the user.

There are 6 combinations of supply voltage and frequency: 230V/50Hz, 230V/60Hz, 115V/50Hz, 115V/60Hz, 100V/50Hz and 100V/60Hz; the Specification section gives the operating range for each version. To operate correctly the AC1000 requires an accurate and stable input frequency. It is not designed to operate from portable generators or battery inverters and it will not function when powered from a source that has a high impedance at 1kHz such as an isolating transformer with a split bobbin.

The AC1000 does not function as an uninterruptable power supply (UPS), a transient suppressor or a voltage stablizer.

Fuse

The AC fuse is located in the fuse drawer in the lower part of the IEC inlet connector. To change the fuse remove the line cord and open the fuse drawer with a suitable tool.

The correct fuse type for all operating voltages is 20 x 5mm 5A(T) 250V HBC time-lag. Make sure that only fuses with the required current rating and of the specified type are used for

replacement. The use of makeshift fuses and the short-circuiting of fuseholders are prohibited.

Installation

Mains Lead

When a three core mains lead with bare ends is provided this should be connected as follows:

As the colours of the wires in the mains lead of this apparatus may not correspond with the coloured markings identifying the terminals in your plug proceed as follows:

The wire which is coloured green-and-yellow must be connected to the terminal in the plug which is marked by the letter E or by the safety earth symbol shown above or coloured green or greenand-yellow.

The wire which is coloured blue must be connected to the terminal which is marked with the letter N or coloured black.

The wire which is coloured brown must be connected to the terminal which is marked with the letter L or coloured red.

Any interruption of the mains earth conductor inside or outside the instrument will make the instrument dangerous. Intentional interruption is prohibited.

BROWN - MAINS LIVE BLUE - MAINS NEUTRAL

GREEN/YELLOW - EARTH Safety Earth Symbol

WARNING! THIS INSTRUMENT MUST BE EARTHED.

Connections

With the POWER switch off ( ), connect the AC1000 to the AC supply using the mains lead provided.

With the LOAD POWER switch set to DIRECT, connect the load to the AC socket on the front panel; the unit should have been supplied with a socket suitable for local appliance connectors.

If the 'load' is a HA1600 Power and Harmonics Analyser, connect the fixed LOAD POWER lead of the HA1600 to the front panel socket of the AC1000.

Switching On Supply Power

It is recommended that the load is turned on by its own power switch and that the LOAD POWER switch is set to DIRECT before the AC1000 is turned on by setting the POWER switch to

the LOAD POWER switch set to DIRECT the correction circuit is bypassed and the load is connected directly to the incoming AC line; this avoids the possibility of any surge current associated with switching on the load causing damage to the power output amplifier. Note that if a HA1600 is connected to the AC1000, the load connected to the HA1600 should be switched on too.

When the power is first switched on, an internal relay bypasses the correction circuit so that any surge current to the load bypasses the power output stage should the LOAD POWER switch have been left set to CORRECTED. The buzzer sounds a pulsed tone while the correction circuit is being bypassed, see Audible Warnings section.

Operation

l. With

Switching On CORRECTED Load Power

With the POWER switch on ( l ) and the LOAD POWER switch in the DIRECT position the load is connected directly to the incoming AC supply.

A few seconds after the POWER switch has been turned on ( l ) the buzzer tone will cease, indicating that the correction circuit has stabilised. The LOAD POWER switch may then be set to CORRECTED, providing the load with a corrected supply which is harmonically pure. There is a brief interruption of the AC supply to the load (<2ms) at switch-over; this, however, is well within the minimum interruption period (10ms) that equipment must withstand to comply with other aspects of EMC immunity, so should present no problem.

Voltage, Frequency, Power and Harmonic Purity in CORRECTED Mode

The AC1000 does not change the frequency of the incoming AC supply. Note that not all national supplies guarantee to meet the ±0·5% frequency specification required by EN61000-3-2, although in practice this will generally be the case.

Similarly, local supply voltage variations mean that the AC1000 will not generally meet the ±2% voltage tolerance required by EN61000-3-2 unless it is supplied from a variable voltage of suitable power rating such that the output voltage can be adjusted to the required limits. In practice this is easily done because the supply voltage changes quite slowly, giving a reasonable time within specification before further adjustment is needed.

The AC1000 will supply up to 1000VA at 230V, up to 500VA at 115V or up to 440VA at 100V; the maximum load current in all cases is 4·4Arms.

Because the input distortion of the incoming AC supply is undefined it is not possible to guarantee the harmonic purity of the output. However, in practice the AC1000 will produce an output which meets the stringent source requirements of EN61000-3-2 even when the AC supply is severely distorted.

If the AC1000 is being used as a power source for a HA1600, the HA1600 can be used to monitor the quality of the corrected supply voltage. Voltage, frequency and harmonic distortion can be continuously monitored and a 'PASS' or 'FAIL' message shown in the Meter display to indicate whether the corrected source is compliant with the requirements of EN 61000-3-2 or not.

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