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1. Reset Averaging Resets measurement averaging see A command Service Request SRQ on Q1 SRQ off QO Status Byte Serial Poll Return status byte Spoll xx xx PA2100 IEEE address Bit 0 Averaging complete logic 1 when averaging complete Bit 6 SRQ bit logic 1 is set when service is requested Bit 7 Data ready logic 1 when data ready IEEE 488 Control of Parallel Port Sends an 8 bit number BO to B255 to parallel interface Eg sending B255 will send 11111111 to the parallel interface Sending B3 will send 0000001 1 to the parallel interface READING RESULTS Return display measurements RO In this mode the PA2100 is configured to return display measurements when read This is the default setting In this mode an IEEE read will return a single line consisting of the two display measurements This mode cannot be used for harmonic measurements see R1 command Selecting the Inrush function will automatically return to the RO mode Return all results mode R1 In this mode the PA2100 will return all the measurement results usually obtained on the printout Voltage harmonics and current harmonics will be included if the harmonic function has been previously selected The number of harmonics sent will depend on the harmonic number selected The R1 command acts as a trigger At the end of the next measurement cycle following R1 the results will be sent to the IEEE output buffer ready to be read Measurements will not be available un2. 1a Hex The baud rate is fixed at 9600 for transmit and receive To program the PC RS232 port use 8 data bits and two stop bits and no parity Use hardware handshaking The 9 way plug on the rear panel has a standard pinout and will connect to a PC by a standard null modem cable The 9 way connector pins are Not Connected Rx Tx CTS OV Not Connected RTS CTS Not Connected 0200 ODOUR eo NO 24 Section 9 Parallel Interface Parallel Port The parallel printer output allows the user to send all the PA2100 measurements directly to a printer fitted with a Parallel Centronics input A standard PC type parallel printer cable 25 pin D to Centronics is required to connect the PA2100 to a printer The data is sent to the parallel port when the PRINT button is pressed If the print key is pressed and the PA2100 is not connected to a printer the PA2100 will display Hold Press PRINT again to remove this message Read the relevant part of section 5 which describes the PRINT key operation 25 Section 10 A Background to Harmonics A repetitive complex waveshape not a sinewave was deemed too complex to describe until the early 1800 s A French mathematician called Jean Baptiste Joseph Fourier discovered that a repetitive complex waveform could be split or resolved into a number of sinewave frequency components He proved his theory by breaking down a repetitive complex waveshape into a number of
3. Interface IEEE Command Summary Power on default setting Vrms DO Arms D1 VA D2 PF D3 FREQ D4 CFV D5 CFA D6 THDV D7 THDA D8 INRUSH D9 HARM V HV1 HV50 HARM A HA1 HA50 Display measurements mode RO Return both display measurements mode XO Return left hand display only mode X1 Return right hand display only mode X2 Return all results mode li8ke printout R1 Frequency source Volts FV Frequency source Amps FA Frequency fixed 50Hz F5 Frequency fixed 60Hz F6 Averaging fixed A1 Averaging automatic A0 Fast mode off MO Fast mode on no harmonics M1 SRQ on Q1 SRQ off QO Return status byte Spoll address Resets measurement averaging AO or A1 Send 8 bit number to parallel interface BO to B255 The controller should use an EOI end or identify or send a line feed terminator after the IEEE command IEEE COMMAND STRING EXPLANATIONS Return measurements in mode RO and R1 RO allows access to the display results see X commands R1 allows access to the printout data and hamonics all results R1 also acts as a trigger X0 X1 and X2 commands When in RO mode power on default setting the display results are made available in three ways X0 mode Returns both left and right hand display measurements XO is the power on default setting X1 mode The PA2100 will return the left and function display measurements only X2 mode The PA2100 will return the right hand display measurement only 17 Sec
4. dO Sets RO mode and Vrms function Note Upper and lower case can both be used Separate commands by comma or space RO mode will stay selected until the R1 command is received Wait until reading is available by inserting a delay or by reading the status byte Send IEEE read PA2100 will return a string containing Vrms and Watts results Further IEEE reads will return the PA2100 s current result Example B Requesting all results no harmonics using the R1 command VVVVV Ensure that the PA2100 is not in harmonic or inrush mode send any D command Send R1 trigger Use an appropriate delay or monitor status byte before reading IEEE data Send IEEE reads until END is received Returned measurements 236 5 Vrms 0 0613 Arms 14 497 VA 8 423 Watts 0 581 PF 49 97 Hz volts 1 412 CF V 4 260 CFA 00 92 THD V noise 158 58 THD A noise END 21 Section 7 IEEE 488 Interface Example C Requesting harmonics and using R1 command In this example all measurements along with harmonics to the 7 are required Send HV7 or HA selects harmonics Wait until measurements are stable Send R1 This sets mode and acts as a trigger At the end of the next PA2100 measurement cycle results will be stored Use an appropriate delay or monitor status byte before reading IEEE data END string will be received when all results have been read If more results are required send R1 again Retur
5. on the main board It is the only IC with a version number label Updates are available from your local representative or from Powertek Ltd The EPROM can be replaced easily 1 Switch off remove AC power cable and all measurement input connections read safety section 1 2 Unscrew and lift off the top cover 3 Locate the EPROM identifiable by the version number label 4 Using anti static precautions remove the EPROM using an extractor tool to avoid damage to the EPROM or PCB 5 Carefully insert the new EPROM check all internal cables are secure and reassemble the PA2100 6 Power up the PA2100 and check that the new version number is displayed at switch on 7 Check that the PA2100 is working by applying a known input voltage and current Replacement of the EPROM will not affect calibration 35 Section 14 Options Option 03 500Arms 100 1 Current Transducer Option 04 1200Arms 1000 1 Current Transducer Option 05 IEEE 488 Interface Option 05A RS232 Interface Option 06 PA Series Printer Cable Option 09 PA2100 Rack Mounting Kit Option 10 IEEE 488 Cable 2 Metre Option 13 PA2100 UKAS Certificate Option 24 Rear Panel Inputs Option 25 HV 40kVpk 2000 1 Probe Option 28 Additional 1m Test Lead Set Option 28A Additional 3m Test Lead Set Option 49 1250A 125A 1A Toroid Current Transformer 0 2 Option 61 PA2100 Hard Flight Case Option 65 DPU 414 Seiko Thermal Printer Option 65A 20 rolls of paper for option 65 Opt
6. repeat the test several times Where applicable always allow the circuit under test time to discharge before repeating the inrush current test PRINT PRINT is used to print results by sending the measurements to the Parallel Centronics port All printed results are true simultaneous measurements The standard printout consists of the following parameters Vrms Arms VA PF Watts Hz Volts Amps 50Hz or 60Hz CFV CFA THD V THD A 12 Section 5 Front Panel Controls If harmonic analysis has been selected before pressing printout the PA2100 will print all the above along with voltage and current harmonics The number of harmonics sent to the printer will depend on the harmonic number selected For example if harmonic 9 is selected and PRINT is pressed the PA2100 will print the odd voltage and current harmonics up to the 9 eg 1 3 5 7 and 9 Selecting an even harmonic number Say 14 will send both odd and even voltage and current harmonics to the printer up to the 14 If the PRINT key is pressed and the PA2100 is not connected to a printer the PA2100 will display Hold Press PRINT again to remove this message Additional Set up Functions The following keys allow access to additional set up functions by holding the key in for approximately 2 seconds VA Access to calibration PF Control of averaging FREQ Selection of Frequency Source INRUSH Set starting range of Inrush VA Access to Ca
7. 0Vrms for 1 second 20 0 2 Rdg 0 2 Range 0 02 per kHz 10mV 90dB 1 kHz 100V with 1 KQ Imbalance 1 MQ 12pF 4 V digit 0 0144Apk to 125 00Apk 600Arms with Option 03 1200Arms with Option 04 20Arms 125Apk Overload 500Arms for 1 second 20 0 2 Rdg 0 2 Range 0 02 per kHz 2mA lt 10mA 1 kHz 100V applied to Hi and Lo terminals 0 0202 0 4 Rdg 0 2 range 2mW 0 02 PF per kHz 0 2 Rdg 0 1 range 0 4 Rdg 0 2 range 38 Section 16 Specifications POWER FACTOR Range Capacitive load Inductive load Accuracy CREST FACTOR Range Accuracy INRUSH CURRENT Range Accuracy Frequency Range Accuracy HARMONIC ANALYSIS Range Fund Accuracy Harm Accuracy THD Range Accuracy INTERFACES ENVIRONMENT DIELECTRIC STRENGTH POWER INPUT DIMENSIONS WEIGHT 0 000 to 1 000 2 Leading PF Lagging PF 0 002 0 0005 PF per kHz 1 to 20 0 002 0 1Apk to 125Apk Up to 1200Apk with Option 04 1 5 5Hz to 125kHz 0 1 of reading DC Fund to 50 0 2 Rdg 0 2 Range 0 1 0 02 per kHz 0 1 to 999 9 Via display 2 to 999 9 0 3 0 01 per kHz Standard Parallel Centronics Printer port Options 05 IEEE 488 Options 05A RS232 Operating Temperature 0 C to 50 C Storage Temperature 40 C to 60 C Humidity 10 90 RH non condensing Inputs to case 3kV AC 50 60Hz for 1 minute AC line input to case 2kV AC 50 60Hz for 1 minut
8. 110 0 60 00 4 33 0 20 00 3 16 0 10 00 2 5 0 2 400 1 2 5 1 200 Range Current range Applied calibration level Number Amps Peak Amps rms 8 125 0 16 0 7 62 5 16 0 6 21 3 10 0 5 11 0 5 0 4 3 6 2 0 3 1 8 1 0 2 0 6 0 24 1 0 3 0 12 If a mistake is made during any stage of the calibration just switch off and start again The previous calibration will remain intact A new calibration is stored when SAVE is selected 33 Section 12 Calibration 10 11 12 13 14 To enter calibration mode hold down the VA button for approximately 2 seconds The left hand display will show Code the right hand display will show Enter the calibration code 1508 Use the numbers under the keys Left hand display will show CAL right hand display will show V or A Select V Voltage calibration by pressing Vrms If current calibration is required then select Arms Vr1 will be displayed in the right hand display CAL will remain in the left hand display At this point it is possible to increment up and down to other ranges using the THD up and INRUSH down keys If a full calibration is required start with voltage range 1 Vr1 Apply the recommended voltage see the voltage calibration table Press the HARM key enter to begin calibration The actual voltage reading will be displayed in the left hand display When the PA2100 averaging is complete the left hand voltage display wil
9. Contents Section 1 Safety Precautions 1 The PA2100 is constructed in accordance with the requirements of IEC 348 class This ensures electrical safety when all normal safety precautions are taken 2 The AC power cord should be inserted into a power outlet with a protective ground earth contact The PA2100 rear panel ground terminal should be used for additional safety 3 Check that the applied AC power input voltage does not exceed the maximum AC power input voltage of the PA2100 4 The AC power cord should be inserted into a power outlet with ground contacts before connections are made to the measurement inputs 5 The instrument should only be opened by qualified personnel understanding the danger of electrical shock hazards 6 The outer cover should not be removed without isolating the AC power input and removing the measurement input cables The measurement input circuitry is isolated and therefore floating so care must be taken to ensure that the measurement input signals are completely removed 6 The AC power input cable and measurement input cables should be in good condition and replaced if any sign of damage or wearing is noticeable Section 2 Getting Started TAKE TIME TO READ THE SAFETY PRECAUTIONS Accessories included with the PA2100 AC power cord Spare 1AT fuse Spare 20A current measurement input fuse Calibration Certificate Certificate of Conformance User Manual Input cables and alligator clip
10. ar to traceable voltage and current standards listed in the calibration section Calibration of the PA2100 requires entry of a four digit passcode available from Powertek If the message Cal is displayed after power on this means the PA2100 may be uncalibrated Contact your local Powertek representative for help Section 2 Getting Started Packaging The PA2100 is a precision instrument and requires careful packaging to prevent damage during transit If the instrument has to be transported use the packaging materials provided by Powertek or packaging materials of a similar quality Ensure that the PA2100 is placed in a polythene bag before packing to prevent ingress of moisture Section 3 Overview of the PA2100 The PA2100 AC Power Analyser is designed to measure the following electrical parameters with both sinusoidal and distorted input signals Volts Volts rms Amps Amps rms Watts Real Power VA Apparent Power PF Power Factor Freq Fundamental Frequency Hz VCF Crest factor Volts ACF Crest factor Amps THD V Total Harmonic distortion Volts THDA Total Harmonic distortion Amps HARM V Voltage harmonics orders 1 to 80 HARM A Current harmonics orders 1 to 80 INRUSH A Inrush Current The above measurements are all determined from the PA2100 voltage and current inputs using internationally recognised conventions The voltage input is an isolated high impedance input of 1 Mohm The current is measured using a fully isolated low i
11. different frequencies He then added the frequencies components back together and created the original complex waveshape So what are harmonics A complex waveshape always has a base or fundamental frequency the lowest frequency in the complex waveshape and a number of higher frequencies that are multiples of the fundamental frequency For example a 1kHz square wave is known to consist of odd harmonics Harmonic Number Frequency 1 Fundamental 1kHz 2 3kHz 5 5kHz ys 7kHz 9 9kHz pr 11kHz etc to infinity Impact of Harmonics Today s AC power distribution system was designed to operate with near sinewave voltages and currents Many loads connected to the AC supply cause the voltage and current to become non sinusoidal These additional frequency components flowing in devices like power transformers power factor correction capacitors circuit breakers and AC motors can cause heating and damage The harmonics also cause a lower system power factor which increases the required generation VA capacity and therefore cost Electricity utilities and equipment manufacturers around the world are seeking to quantify and limit the level of harmonic pollution because of the above Some typical loads that cause harmonic currents to flow Large AC DC motor drives Arc welders Large rectifiers Induction heating systems Electronic lighting ballasts Computers Switching power supplies Uninterruptible power supplies 26 Section 10 A Back
12. e AC line input range 90Vrms to 264Vrms AC AC line input frequency 45Hz to 450Hz AC line input fuse protection 20mm 1AT anti surge Power consumption 16W 30VA Width 215mm x Height 144mm x Depth 390mm 5 5kg 6kg boxed 39 Section 17 Index AC Power Input 3 14 Accessories 3 gt 3 D c Back Panel Connections 14 Calibration 3 31 32 CF Crest Factors 10 Connecting the PA2100 6 Connection Diagram 7 Control of averaging 13 Current Transformers 35 E EPROM replacement of 34 Firmware 34 FREQ 10 March 2003 Frequency Source 10 13 Front Panel Keys 9 Fuse Protection 3 HARM Harmonics 1 1 Harmonic Analysis 25 29 IEEE 488 14 15 IEEE 488 Commands 16 INRUSH 12 Inrush Range 13 Options 35 PF Power Factor 9 Principle of Operation 27 PRINT 12 Printer port 14 24 40 RS232 14 23 Safety Precautions 2 Specification 37 THD 11 30 VA 9 Vrms 9 Ww Watts Calculation 28
13. en the polarity sign may alternate between plus and minus The true power factor is valid where phase shift between fundamentals has occurred or when harmonic distortion is present Section 5 Front Panel Controls FREQ Selecting frequency will display the fundamental or base frequency of the input signals Frequency can be detected from either the voltage or currents inputs This is necessary if one of the input signals is very distorted ie PWM signals The default frequency source is the voltage channel Always check the frequency is stable and correct before recording a measurement Selecting the frequency source V or A The PA2100 can measure input frequency from either thhe voltage or current with the capability of locking the frequency to 50Hz or 60Hz explained next Holding in FREQ for two seconds will display whether the frequency is found from the voltage or current input or locked to 50Hz or 60Hz U Frequency source is voltage A Frequency source is current 50 Frequency is locked at 50Hz 60 Frequency is locked at 60Hz Press Vrms or Arms to select the required frequency source Pressing frequency again returns the user to frequency measurement Locking to 50Hz or 60Hz These modes are used when the measured voltage and current waveforms are high frequency signals modulated by the AC power frequency eg 50Hz or 60Hz To achieve stable measurement with these conditions all measurements have to be
14. ground to Harmonics Harmonic Analysis using the PA2100 The PA2100 uses a Discrete Fourier Analysis DFT to measure the voltage and current harmonic magnitudes This gives an excellent rejection of unwanted frequencies contained in the waveform The PA2100 will track the fundamental frequency continuously to ensure the harmonics are analysed at the correct frequency Harmonics 2 to 50 are displayed as a percentage of the fundamental rms The fundamental H1 is displayed in Vrms and Arms For more information on Harmonic Analysis see section Principle of Operation 27 Section 11 Principle of Operation The main components of the PA2100 Power Analyser Analog input board input sections for voltage and current Main processor board mother board Keyboard and display board Power supply Operational Description The PA2100 analog board attenuates or amplifies the input signals as required A current shunt converts the input current into a voltage that is then attenuated or amplified accordingly These analog input signals are then fed to an analog to digital convertor ADC converting the input signal into 8 bit numbers the sample rate selected depends on the input signal frequency All gain stages and attenuation on the analog boards are controlled by the microprocessor via an opto isolated serial interface link The 8 bit sample data is transferred over the opto isolation barrier to the microprocessor The input voltage a
15. ion 65B Battery pack for DPU 414 Seiko Thermal Printer SAFETY WITH CURRENT TRANSFORMERS Always connect the current transformer to the PA2100 current input before attempting to clamp around the current carrying conductor As with any clamp on current transducers care must be taken to ensure that the clamp is securely closed before use Periodically the clamp magnetic surfaces should be inspected and cleaned as required An air gap in the magnetic circuit will result in large amplitude and phase shift errors 36 Section 15 Warranty and Disclaimer The PA2100 is warranted against defects in materials and workmanship for a one year period Powertek reserves the right to decide if the repair is under warranty This will not apply to defects resulting from misuse or unauthorised modifications Powertek cannot accept legal liabilities for any inaccuracies in this documentation Powertek reserves the right to alter the specification without notice 37 Section 16 Specifications Measurement Bandwidth VOLTS Display Resolution Measurement range Max input volts Max input CF Accuracy Common mode V rejection Input Impedance CURRENT Display Resolution Measurement range Max input Amps Max input CF Accuracy Common mode V Rejection Input Impedance POWER W W 45 65Hz VA DC 5Hz to 250kHz 4 Y2 digit 700mVrms to 1000V rms 1440Vpk 200mVrms with blanking disabled 1000Vrms 1440Vpk Overload 300
16. l stop updating and will appear in the right hand display A four digit calibration constant has to be calculated and entered Applied voltage The calibration constant x 2048 PA2100 reading Enter the 4 digit calibration constant the PA2100 will automatically accept this number Range 1 is now calibrated Vr2 is now displayed in the right hand display If a mistake is made enter any number then return to the range using the up down keys and recalibrate starting from step 5 Select the voltage input level required for range 2 Vr2 Repeat steps 5 to 9 for ranges 2 to 8 until SAVE is displayed The calibration constants can now be stored The PA2100 will show SAVE in the right hand display after calibration of range 8 press HARM enter to save the calibration Check each voltage or current range by applying a traceable reference level to ensure that the PA2100 meets its specification To calibrate current start from step 1 and enter Arms instead of Vrms at step 4 Apply the current calibration levels shown before the procedure and repeat steps 5 to 12 If you check the current with no voltage applied do not forget to set the frequency source to Amps 34 Section 13 Firmware Introduction Powertek has an on going firmware development for all its products At regular intervals new features and upgrades are made available Firmware up grades are possible by the replacement of an EPROM situated
17. libration Holding in the VA key allows access to the voltage and current calibration A pass code has to be entered before any change to calibration can be made For a detailed explanation see section on Calibration PF Control of Averaging Auto or Set Auto All measurements are automatically averaged to give stable results Automatic averaging will average the last 16 measurements One measurement is typically 0 75 seconds If there is a step change trend in the input voltage current or frequency the averaging will automatically disable to allow immediate observation of the actual input signal or frequency Stable results and a fast response to change is achieved using auto averaging Auto averaging is the power on default setting of the PA2100 Set Some applications require fixed measurement averaging An example of this is making measurements with an unstable load or AC supply here averaging has to be Set Example Hold PF key in for 2 seconds left hand display will show AV right hand display will show AUto Use select keys THD amp INRUSH to change from AUto to SEt followed by pressing enter HARM to accept the selection The PA2100 will return to measurements FREQ Selection of Frequency Source The frequency measurement of the PA2100 can be obtained from the voltage current or fixed at 50Hzor 60Hz For a detailed explanation see earlier in this section INRUSH Set starting range of Inrush To ensure that the peak c
18. made over a complete number of cycles of the AC supply frequency of 50Hz or 60Hz This mode is available by holding down the FREQ button for two seconds Pressing 5 or 6 will select 50Hz or 60Hz mode Pressing frequency again returns the user to frequency measurement The setting is saved and recalled at power on A typical application is measurement on the output of electronic lighting ballasts Here the output frequency could be 30kHz or more modulated by a large 50Hz or 60Hz AC supply ripple component For stable measurement it is necessary to measure over a complete number of cycles of the modulation frequency eg 50Hz or 60Hz CF EA This function displays the crest factor of the input voltage or current waveform based on the ratio of waveform peak rms After selecting CF the PA2100 will prompt V or A press Vrms or Arms to select voltage or current crest factor Crest factor allows the user to see if the waveform is deviating from a sinewave The crest factor for a pure sinewave is 1 41 10 Section 5 Front Panel Controls THD p Total Harmonic Distortion THD displays the percentage ratio of the harmonic rms and noise of the fundamental rms After selecting THD the PA2100 will prompt V or A press Vrms or Arms to select voltage or current THD The LED under the key will light The THD range using the front panel display is 3 to 999 Pure THD harmonic rms fundamental rms as a percentage is available using the PA2100 wi
19. mpedance shunt 0 02 ohms Both inputs are fully autoranging The wideband inputs permit electrical measurement at high and low frequencies as well as power frequencies A high degree of input isolation allows connection anywhere in the circuit under test Measurements are averaged to give stable readings If there is a step change trend in the input voltage current or frequency the averaging will automatically disable to allow immediate observation of the actual input signal amplitude or frequency Electrical measurements can be made in three ways 1 Viewing measurements from the front panel LEDs 2 Sending results to a standard printer via the parallel printer port 3 Using the optional IEEE 488 or RS232 computer interfaces Section 4 Connecting the PA2100 Quick Guide Before connecting any signals to the PA2100 inputs connect the AC power cord this will provide a safety ground earth for the PA2100 case Ensure the circuit under test is switched off and isolated Connect the PA2100 voltage input across the load the maximum working voltage is 1000Vrms 1440V peak Note that the voltage input high red should connect to the live line side of the load The voltage input low black should connect to the neutral side of the load see connection diagrams Connect the PA2100 current channel in series with the load remember the maximum current is 20Arms 125Apk The current input may be connected in the high live line side of the l
20. n constants are then calculated This means that calibration of the PA2100 does not require adjustment of trim potentiometers or even the removal of the outer case Equipment Required Voltage calibration source 0 02 accuracy or better Range 1Vrms to 500Vrms 50Hz or 60Hz Current calibration source 0 02 accuracy or better Range 0 12Arms to 20Arms 50Hz or 60Hz Alternatively a stable voltage and current source may be used in conjunction with a high accuracy AC voltmeter and current shunt The voltmeter and current shunt are used to measure the applied voltage and current Calibration of the PA2100 voltage and current inputs is all that is necessary All other PA2100 measurement parameters are calculated from the voltage and current inputs Before Calibrating a PA2100 1 A warm up period of 30 minutes is allowed before measurements are taken 2 Allow a 10 second settling time is allowed before recording a measurement 3 The calibration signal ground low is connected to the low terminal Black of the PA2100 4 All instrument accuracy specifications are valid for a 1 year period 5 Room temperature 23 C 2 C 32 Section 12 Calibration Calibration Procedure Allow at least 30 minutes warm up The following two tables show the voltage and current ranges and the applied calibration levels Range Voltage range Applied calibration level Number Volts Peak Voltage rms 8 1440 0 500 0 7 720 0 250 0 6 220 0 120 0 5
21. nd current waveforms are digitized simultaneously Both the V and A channels are isolated 3kV with respect to each other and ground chassis The processor averages the measurement results and sends the data to the two 4 5 digit 7 segment displays All measurements are automatically averaged to give stable readings If there is a step change trend in the input voltage current or frequency the averaging will automatically disable to allow immediate observation of the actual input signal amplitude or frequency The measurement results are made available to the Printer port or IEEE 488 RS232 interfaces 28 Section 11 Principle of Operation The sample data is then analysed using the accepted IEEE and IEC measurement definitions 1 2an Vrms y f V inst dt 2an 0 1 2nn Arms y ET inst dt enn 0 Vpeak Vcf Vrms Apeak Acf E Arms VA Vrms x Arms 1 2an Watts Em 27n 0 Watts PF VA VArs y VA W 29 Section 11 Principle of Operation Harmonic Analysis Harmonics are analysed using a technique known as Discrete Fourier Analysis DFT This technique gives accurate results even when significant noise at other frequencies is present The PA Series Analysers constantly track the fundamental frequency so this allows all harmonics to be analysed accurately Harmonics 2 to 50 are displayed as a percentage of the fundamental rms The fundamental H1 is displayed in Vrms and Arms The a and b
22. ned measurements 236 5 0 0613 14 512 48 434 0 581 49 97 1 412 4 260 00 92 158 58 Vrms Arms VA W PF Hz CF V CFA THD V noise THD A noise 236 40 V 0 0327 A 00 49 70 17 00 54 63 96 00 31 51 27 THD V THD A 22 Section 7 IEEE 488 Interface HINTS FOR READING BACK DATA AFTER DATA DROM THE PA2100 HAS BEEN READ THERE IS A DELAY BEFORE THE IEEE OUTPUT BUFFER IS UPDATED DURING THIS TIME THE PA2100 WILL RETURN A LINE FEED IF THE CONTROLLER SENDS AN IEEE READ BEFORE THE PA2100 IEEE OUTPUT BUFFER IS UPDATED Depending on the harmonic number selected the PA2100 can take several seconds after receiving a trigger R1 to complete all the measurements Before reading the data monitor the status byte or insert a delay before sending IEEE reads When calculating a delay use 0 25 seconds for each harmonic Eg 50 harmonics will take about 12 5 seconds before data is ready 23 Section 8 RS232 Port NOTES FOR USE OF PA2100 RS232 PORT To control the PA2100 through the RS232 port use the command set as detailed in the IEEE 488 User Manual These commands are valid for IEEE and RS232 control The exceptions are the Q1 and Q0 commands which are IEEE specific An extra command c1 is provided for the RS232 This is a command to tell the instrument to send data To read data from the PA2100 send c1 and then read from the RS232 port The end of data sent by the PA2100 is signified by the byte
23. oad or in the low neutral side Ensure that the current input high red is always connected towards the live line of the supply see later in this section Incorrect input polarity will affect only power and power factor polarity other measurements will be correct Damage will not occur from incorrect polarity Check that the frequency reading is stable and correct before recording any other electrical measurements Select the required measurement and allow the PA2100 a few seconds to settle Check that electrical connections to the circuit under test are good and solid Intermittent connections will give incorrect results and are dangerous Use 4mm connecting plugs that are 18mm in length minimum Best results are achieved using 4mm plugs with bunch or lantern type spring contacts especially important for the current input Connect a standard printer to the parallel port to record results this will save you time Section 4 Connecting the PA2100 Quick Guide Connection Diagram AC Supply Neutral PA2100 Amps Input PA2100 Volts Input Load Device Under Test Where possible use this wiring configuration Here the current input is connected in the neutral supply wire note the position of the voltage and current Hi s and Lo s The PA2100 voltage and current Hi terminals should be connected towards the supply Live High If the PA2100 Hi and Lo terminals are connected incorrectly the watts reading is likel
24. s AC Power Input AC voltage selection is not necessary with the PA2100 The PA2100 will accept an AC input voltage from 90Vrms to 264Vrms The input frequency range is 45Hz to 450Hz FUSE PROTECTION 1A AC Power Input Fuse The PA2100 has 1AT 1A anti surge fuse protection situated in the AC power input Should the fuse blow a replacement is supplied with the instrument or available from your local representative For safety reasons always use the correct fuse type size and rating Additional AC input fuse protection is provided inside the power supply If the 1AT fuse blows and the PA2100 does not power up after replacement then check the fuse situated inside the power supply The power supply is easily located by the perforated metal safety cover Hazardous voltages are present on this power supply and section 1 should be read before opening the PA2100 20A Current Measurement Input Fuse For safety a 20A internal fuse is provided for the current measurement input This fuse is designed to blow should the current continuously exceed 20A A replacement is supplied with the PA2100 additional fuses are available from your local representative For safety reasons always use the correct fuse type size and rating This fuse has a high current breaking capacity so it is advisable that a replacement be obtained from Powertek Calibration The PA2100 is calibrated before it is despatched from Powertek The PA2100 should be calibrated once a ye
25. th a printer The THD shown at the end of the printout is then calculated from each of the listed hamonics Greater THD accuracy is achieved if more harmonics are included in the THD calculation see the next section describing the harmonic analysis capability of the PA2100 The THD range using the PA2100 with a printer is 0 1 to 999 HARM Pressing HARM allows access to the voltage and current harmonic analysis After selecting HARM the PA2100 will prompt V or A Voltage or current harmonic analysis can be selected press the Vrms button to select voltage harmonics or Arms for current harmonics After the selection has been made H1 will be displayed in the right hand display the Harm led will light along with the led under the Vrms or Arms key It is possible to increment through the harmonics using the up down keys marked with an arrow eg THD and Inrush Use these keys to increment to the desired harmonic Keeping the key pressed will cause the PA2100 to increment quickly through the harmonics The harmonic number H1 to H50 is displayed in the right hand display The harmonic amplitude is displayed in the left hand display Harmonics H2 to H50 are displayed as a percentage of the fundamental rms The fundamental H1 is displayed in actual volts or amps rms Printing Harmonics Pressing Print will send the voltage and current harmonics to the parallel printer port The number of harmonics sent to the printer will depend on the harmonic n
26. til one measurement cycle following the R1 command 19 Section 7 IEEE 488 Interface Returned measurement data using R1 All the results normally found on the printout are stored ready to be read An IEEE read is required for each result After the last result ha been read the instrument will send an END message to indicate all results have been sent Any further IEEE reads ill return a line feed To read further measurements another R1 trigger must be sent READING RESULTS RO Display measurements mode In this mode display results are returned on a single line in the format function display watts display Eg if Vrms is the function selected the data string returned will be x xxxx Vrms x xxxx W Oah all strings will be terminated with a line feed Oah and EOI will be set Inrush measurements will only return x xxxx A pk Oah R1 Return all results In this mode many results are stored each string has to be read a line at a time Eg Eleven IEEE reads would need to be sent To read the following 236 5 Vrms 0 0613 Arms 14 512 VA 48 434 W 0 581 PF 49 97 Hz volts 1 412 CF V 4 260 CFA 00 92 THD V noise 158 58 THD A noise END Note the END string indicates that all data has been read All strings will be terminated with a line feed Oah and EOI will be set 20 Section 7 IEEE 488 Interface EXAMPLES Example A Reading Volts and Watts with RO Mode VNN Send RO
27. tion 7 IEEE 488 Interface D display Commands The D command allows the controller to select which measurement is shown on the PA2100 function display Vrms DO Arms D1 VA D2 PF D3 FREQ D4 CF V D5 CFA D6 THD V noise D7 THD A noise D8 INRUSH D9 This command is equivalent to pressing a function select key when the instrument is being used manually In RO mode the PA2100 will return the measurement that has been selected using the D commands Selecting Harmonic Measurements The HV and HA commands allows the controller to select which harmonic measurement is displayed The instrument will then calculate both volts and amps harmonics up to the number selected If an odd number is selected only odd harmonics will be returned If an even number is selected then all harmonics up to the number selected will be returned HARM V HV1 HV50 HARM A HA1 HA50 Setting Frequency Source Frequency Volts FV Frequency Amps FA Frequency fixed 50Hz F5 Frequency fixed 60Hz F6 These settings will not change the current frequency source selection stored in non volatile memory IEEE Fast Mode M1 Enabling IEEE fast mode increases the rate at which the PA2100 will return measurements Harmonics fundamentals PF sign and THD are not available in fast mode Typically 3 readings second Averaging Averaging fixed A1 Averaging automatic AO Sending these commands will also reset measurement averaging 18 Section 7 IEEE 488 Interface
28. ts can be connected to an IEEE 488 bus this means that each instrument has it s own dedicated address enabling the controller to communicate with a specific instrument The PA2100 has a default address of 9 Instruments with fitted with an IEEE 488 interface fall into three categories Talker Able to send results and status Listener Able to receive results Talker Listener Able to receive commands and send results IEEE 488 on the PA2100 is implemented as a full talker listener as defined in the IEEE Standard 488 1978 IEEE 488 1 It implements the following interface functional subset SH1 Source handshake complete capability AH1 Acceptor handshake complete capability T6 Basic talker with serial poll and unaddress if MLA TEO No extended talker L4 Basic listener unaddress if MTA LEO No extended listener SR1 Service request complete capability RL1 Remote Local complete capability PPO No parallel poll capability DC1 Device clear complete capability DTO Device trigger capability CO No controller capability CONTROLLING THE PA2100 OVER THE IEEE 488 INTERFACE BUS The PA2100 is controlled by using the text commands explained in this section Setting the IEEE 488 address 1 Press and hold down Arms 2 Display will show current IEEE address 1 30 3 Use SEL up and down keys THD and INRUSH to select the required address 4 Press HARM to enter the address This is now stored in non volatile memory 16 Section 7 IEEE 488
29. umber selected For example if harmonic 9 is selected and print is pressed the PA2100 will print the odd voltage and current harmonics up to the 9 eg 1 3 5 7 and 9 Selecting an even harmonic number say 14 will send both odd and even voltage and current harmonics to the printer up to the 14 To exit harmonic analysis press HARM the PA2100 will return to Vrms See section on Harmonic Analysis for more information 11 Section 5 Front Panel Controls INRUSH Selecting INRUSH will store and display the largest current peak and is used typically to measure the inrush or starting current of a load at switch on All inrush events lasting 15uS or longer are measured It is possible to clear the peak reading by pressing INRUSH again To ensure that the peak current is captured with short duration gt 600uS inrush current events it is possible to select the starting current range This ensures that the peak current is captured and not missed due to the autoranging process The current ranges of the PA2100 are Range Peak Amps co o0 amp 0nm o l gt Pressing the INRUSH current key and holding in for 2 seconds will display the starting range Use the up and down keys marked with an arrow THD and Inrush to select the desired current range Press HARM to accept the range the PA2100 is now ready to capture the inrush current Switch the load on and observe the peak current reading It is advisable to switch off and
30. urrent is captured with short duration 600uS inrush current events it is possible to select the starting current range This ensures that the peak current is captured and not missed due to the auto ranging process For a 13detailed explanation see earlier in this section 14 Section 6 Back Panel Connections AC Power Input On off Switch and 1AT Anti Surge Fuse The AC power input is a combined AC input connector noise rejection filter on off switch and fuse holder rating 1A Optional IEEE 488 Connector This connector permits connection of the PA2100 to an IEEE 488 interface bus Full talk and listen facilities are implemented Parallel Centronics Printer 25 pin D type connector Connection to any parallel input printer is possible using this standard parallel output port Optional RS232 This connector is a 9 pin D type connector BI directional RS232 serial communication using a data rate of 9600 baud is possible using this port 15 Section 7 IEEE 488 Interface INTRODUCTION The IEEE Interface allows the PA2100 to communicate with a controller typically a computer The PA2100 can be used as part of an automatic test system where the controller sends commands to the instruments connected to the IEEE 488 interface bus The IEEE 488 interface bus allows the controller to instruct an instrument to make measurements the controller can then ask the instrument to return the measurement results Several instrumen
31. values below represent the inphase and quadrature components Func t represents the input waveform 1 2an a f Func t x sin not dt 27n 0 1 2an b f Func t x cos nox dt 2nn 0 Both magnitude and angle are calculated using these formulae Harmonic Magnitude Y a2 b Angle arc tan 30 Section 11 Principle of Operation Total Harmonic Distortion THD Two types of formulae are available to analyse THD THD Range 0 1 to 999 9 calculated from the harmonics and included at the end of the printout THDV y VH2 VH3 VH50 THDA y AH2 AH3 AH50 Mathematically equivalent to y VH2 VH3 VH50 THDV x 100 VH1 y AH22 AH32 AH502 THDA x 100 AH1 THD noise range 3 to 999 9 using front panel display y Vrms VH1 THDV 4 noise x 100 VH1 Y Arms AH1 THDA 44 noise x 100 AH1 THD noise will take account of any DC or noise contributions present in the waveform The calculation time of THD noise is much shorter than THD THD noise will often give a larger number than the THD 3l Section 12 Calibration PA2100 Calibration Procedure Introduction Calibration of the PA2100 voltage and current inputs is performed by applying a traceable reference level to each voltage and current range The actual PA2100 reading and reference are then compared the calibratio
32. y to be a minus number no damage will occur Section 4 Connecting the PA2100 Quick Guide AC Supply Neutral PA2100 Amps Input PA2100 Volts Input Load Device Under Test With this configuration the current input is connected in the live supply wire note the position of the voltage and current Hi and Lo s Section 5 Front Panel Controls Power Power in watts is displayed continuously in the right hand display of the PA2100 True AC and DC power is displayed along with plus or minus indications to show direction of power flow Vrms E True Rms voltage will be displayed in the function display The displayed Rms includes both the AC and DC component in the waveform When selected the LED under the key will illuminate Arms eem True Rms current in Amps will be displayed in the function display The displayed Rms includes both the AC and DC component in the waveform When selected the LED under the button will illuminate VA Selecting VA will display the product of Vrms and Arms Often referred to as the maximum demand of a system required for rating purposes PF E Pressing PF power factor will display the true power factor over the range 0 to 1 using the definition W VA Polarity indications or show whether the current is lagging or leading voltage current leading voltage capacitive current lagging voltage inductive If the voltage and current are exactly in phase th
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