Rotek 800 Series User manual

Rotek® Instrument Corp., 390 Main Street, Waltham, Massachusetts 02154 USA
Tel. [phone]
Fax. [phone]
SERIES 800
PRECISION POWER/ENERGY
METER CALIBRATORS
17th Printing
Effective Starting Serial Number 675

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CERTIFICATION
Rotek Instrument Corp. certifies that this instrument has been calibrated to meet or exceed all
the specifications contained in this manual prior to being shipped from the factory. The calibration
has been performed with instruments, the accuracy of which are traceable to the National Institute of
Standards and Technology (N.I.S.T.) formerly known as the National Bureau of Standards (N.B.S.).
WARRANTY
Rotek Instrument Corp. warrants each instrument manufactured by it to be free from defects in
material and workmanship for a period of one year from date of delivery to the original purchaser,
provided the instrument is used in accordance with the instructions in this manual. Rotek's obligation
under this warranty is limited to servicing or adjusting an instrument returned to the factory,
transportation charges prepaid, for that purpose. This is the only warranty offered in connection with
the sale of this instrument, no other warranty is implied. Rotek is not liable for consequential
damages.
If a fault in operation occurs, the following steps should be taken:
1. Notify Rotek Instrument Corp. giving full details of the faulty operation, the model
number and serial number of the instrument. On receipt of this information, service
data or shipping instructions will be provided.
2. On receipt of the shipping instructions, forward the instrument prepaid and all
necessary repairs will be made at the factory.
If it is necessary to return this instrument to the factory, it should be shipped in the original
packing carton. If it is not available, use any suitable rigid container with adequate packing to protect
the unit during transit. Do not ship an unprotected instrument with peanuts (Pieces of foam or other
material) as packing. Always prepare an inner carton.

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TABLE OF CONTENTS
1.0 General Information ..............................................................................................................1
1.1 Description...............................................................................................................1
1.2 Models and Options.................................................................................................1
1.2.1 Model 800A Wattmeter Calibrator........................................................1
1.2.2 Model 811A Power Energy Calibrator..................................................1
1.2.3 Models 800AE and 811AE...................................................................1
1.3 Specifications...........................................................................................................2
1.3.1 Models 800A/811A...............................................................................2
1.3.2 Models 800AE/811AE..........................................................................4
2.0 Operating Instructions ...........................................................................................................5
2.1 Power Requirements ...............................................................................................5
2.2 Installation................................................................................................................5
2.3 Controls and Displays..............................................................................................5
2.4 General Operating Information ................................................................................9
2.4.1 Model 800A/800AE...............................................................................9
2.4.1.1 Entering Voltage...................................................................................11
2.4.1.2 Entering Volt-Ampere...........................................................................11
2.4.1.3 Applying Excitation...............................................................................11
2.4.1.4 Power Factor........................................................................................11
2.4.1.5 Fractional Setting..................................................................................11
2.4.1.6 Deviation Function - Error Measurement.............................................11
2.4.1.7 Use as a Voltage Source......................................................................12
2.4.1.8 Use as a Current Source......................................................................12
2.4.2 Model 811A/811AE...............................................................................12
2.4.2.1 Energy Instruments With Electrical Pulse Output ................................12
2.4.2.2 Rotating Instruments With No Pulse Output ........................................15
2.4.2.3 Rotating Instruments, Fixed Energy.....................................................18
2.4.2.4 Availability of Additional Signals...........................................................19
3.0 Theory of Operation..............................................................................................................21
3.1 Introduction ..............................................................................................................21
3.1.1 Voltage .................................................................................................21
3.1.2 Current..................................................................................................23
3.1.3 Phase Control.......................................................................................23
3.2 System Operation ....................................................................................................23
3.2.1 Voltage Function (08-800-002/1) .........................................................26
3.2.2 Current Function (08-800-002/2)..........................................................26
3.2.3 Phase Control Function (08-800-002/3)...............................................26
3.3 Controls....................................................................................................................26
3.3.1 Local Mode...........................................................................................32
3.3.1.1 Directly Applied Control Signals...........................................................32
3.3.1.2 µP Treated Signals...............................................................................32
3.3.1.3 Use of µProcessor Generated Control Signals....................................34
3.3.2 Remote Mode.......................................................................................34
4.0 MAINTENANCE....................................................................................................................35
4.1 Required Test Equipment........................................................................................35
4.2 Performance Tests...................................................................................................35
4.2.1 AC Voltage Accuracy Tests..................................................................35
4.2.2 Current Accuracy Tests........................................................................35
4.2.3 Voltage Distortion Test.........................................................................40
4.2.4. Current Distortion Tests .......................................................................40
4.2.5 Power Accuracy Tests..........................................................................40

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4.2.6 Deviation Test.......................................................................................40
4.2.7 Fractional Divider Tests........................................................................43
4.3 Calibration Procedure...............................................................................................43
4.3.1 Model 800A/811A Calibration Procedure .............................................43
4.3.2 Model 800AE/811AE Calibration Procedure ........................................48
4.3.3 Factory Adjustments.............................................................................51
4.4 Periodic Maintenance...............................................................................................51
4.4.1 Air Filter.................................................................................................51
4.4.2 Relays...................................................................................................52
4.5 Troubleshooting........................................................................................................52
4.5.1 Access...................................................................................................52
4.5.2 Power Supply Voltages.........................................................................52
4.5.3 Suspected Voltage Failure....................................................................54
4.5.4 Suspected Current Failure....................................................................58
4.5.5 Suspected Phase Function Failure.......................................................60
4.5.6 Line Synchronization Function Erratic..................................................60
4.5.7 Isolating an Analog Switch Fault...........................................................61
5.0 IEEE-488 INTERFACE..........................................................................................................63
5.1 Description................................................................................................................63
5.2 Data Entry.................................................................................................................64
5.3 Serial Poll Code........................................................................................................64
5.4 Default Conditions....................................................................................................67
5.5 Asserting the Remote State .....................................................................................67
5.6 Programming Examples...........................................................................................67
5.6.1 Initializing ..............................................................................................68
5.6.2 Establishing an Active Defined Condition.............................................68
5.6.3 Enabling Operate..................................................................................69
5.6.4 Reading the Deviation Meter Data........................................................69
5.6.5 Reading the Energy Delivered Data.....................................................69
5.6.6 Ending a Test Routine ..........................................................................70
5.6.7 Precautions...........................................................................................70
6.0 Parts List................................................................................................................................71
6.1 List of Recommended Spare Parts ..........................................................................71
6.2 Replaceable Parts....................................................................................................73
6.2.1 Front Panel Assembly...........................................................................73
6.2.2 Main Assembly......................................................................................75
6.2.3 Rear Panel Assembly ...........................................................................77
6.2.4 Relay Output Assembly ........................................................................81
6.2.5 Annunciator Assembly..........................................................................83
6.2.6 Control Logic Assembly........................................................................85
6.2.7 CVA Assembly......................................................................................91
6.2.8 Phase Control & Sense Assembly........................................................99
6.2.9 Oscillator Assembly ..............................................................................107
6.2.10 Reference Assembly.............................................................................113
6.2.11 µP/IEEE Interface .................................................................................119
6.2.12 Switch Circuits ......................................................................................123
7.0 SCHEMATICS AND LOCATION DRAWINGS......................................................................125

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1. General Information
1.1 Description
The Series 800 Power and Energy Meter Calibrators are precision sources of low distortion
alternating voltage and current, providing voltages from 11 to 749 Volts RMS and currents from 0.011
to 50 Amperes at frequencies of 50, 60, or 400Hz. The separate voltage and current outputs of the
Calibrators may be connected respectively to the voltage and current input terminals of wattmeters
and watt-hour meters for calibration. The Series 800 Calibrators have a separate control for the
phase of the current with respect to the voltage, resulting in a power factor which can be varied from
minus zero lagging through unity to plus zero leading. Through the use of the deviation control it is
possible to measure wattmeter percent error directly and display it in decimal form.
The Series 800 Calibrators have unique controls which allow the user to set the meter
excitation voltage and volt-amperes value; the excitation current is automatically determined. Entry of
voltage, volt-ampere, frequency and power factor settings may be accomplished through front panel
controls or remotely by the IEEE-488 Interface. The Series 800 Calibrators also include a Fractional
Setting control to simplify testing of meters (primarily analog) with non decimal cardinal scale points.
1.2 Models and Options
1.2.1 Model 800A Wattmeter Calibrator
The Model 800A Power Calibrator is used for the calibration and testing of wattmeters and watt
transducers. The range of voltage available coupled with the high burden capability make it suitable
for a variety of different instruments.
1.2.2 Model 811A Power Energy Calibrator
The Model 811A Power/Energy Calibrator is used for the calibration of watt/energy meters and
transducers. It has special features for delivering and displaying precise amounts of energy.
1.2.3 Models 800AE and 811AE
The 800AE and 811AE offer 100 ppm accuracy of apparent power and energy for power
factors from unity to ± zero power factor.
Operation of the 800AE and 811AE is identical to that of the Models 800A and 811A. The
Models 800AE and 811AE, however, have an Enhanced Mode which is operable over the range of
80 to 129, 160 to 279 volts and 1.1 to 5.9 amperes and at all power factors. An LED indicator is
automatically illuminated when operating in the Enhanced Mode ranges. The 811AE Power and
Energy Calibrator is ideal for testing working watt-hour standards. The 800AE power calibrator finds
application in watt and VAR transducer testing and in low power factor applications, such as motor
and transformer loss measurement calibration.
Please note that when operating in the Enhanced Mode the Fractional Setting control and the %
Deviation function are inhibited.

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1.3 Specifications
Specifications apply after 60 minutes of warm-up at ambient temperature of 25 ±5°C, a line
frequency of 50 to 60Hz, at nominal line voltage ±5%, includes loading and maintains for a period of 6
months. All specifications are described as maximum limits unless otherwise stated.
1.3.1 Models 800A/811A
Voltage Output Characteristics
Voltage Range: 11-749V RMS
2 ranges: 11-120, 121-749
Voltage Accuracy: ±(0.02% of reading +0.001% of range).
Distortion (Harmonic): 0.05% RMS for resistive loads.
0.05% reading +0.01% range RMS for inductive loads.
Rectifier loads may cause additional distortion.
Line related and other noise: 0.01% reading +0.002% range RMS.
Cycle to Cycle Instability: ±0.01% reading +0.002% range peak to peak.
Resolution: 1 Volt.
Voltage Burden: 11-120V: 300mA, 120 to 100V decreasing to 50mA at 11V.
121-279V: 145mA, 279 to 220V decreasing to 75mA at 121V.
280-750V: 45mA 749 to 700V decreasing to 15mA at 280V.
Instability: 20ppm per hour reading non cumulative.
50ppm per day reading non cumulative.
100ppm per month reading non cumulative.
Temp. Coefficient: ±(10ppm reading +2ppm range) per °C.
Line Voltage Sensitivity: ±5ppm/percent line voltage change.
Connections: Four wire.
Current Output Characteristics
Current Range: 0.011-50 Amperes.
3 Ranges: 0.011-1.0999A; 1.1-10.999A; and 11.000-50A
Current Accuracy: 0.011-10.999 Amps: ±(.025% reading at Unity PF + 100µA)
11.000-50 Amps, 50/60Hz: ±(0.035% reading + 0.001% range)
11.000-50 Amps, 400Hz: ±0.1% reading
50-75 Amps, 50/60Hz: ±0.06% reading
50-75 Amps, 400Hz: ±0.2% reading
Distortion (Harmonic): 0.05% at 1PF setting, increasing linearly to
0.15% at 0PF setting RMS.
Line related and other noise: 0.01% reading +0.001% range RMS.
Cycle to Cycle Instability: 0.05% reading +0.004% range, peak to peak.
Resolution: 0.001% of scale.

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Compliance: Max. Voltage
Current at Max. Inductance
Range Full Range 50/60 400Hz*
1.0999A 4V 5mHy 125µHy
10.999A 4V 1mHy 30µHy
50A 0.4V 10µHy 4µHy
75A (Optional) 0.1V --------- ---------
Amplitude Instability: 20ppm per hour non cumulative.
50ppm per day non cumulative.
100ppm per month non cumulative.
Temp. Coefficient: ±(15ppm reading +2ppm range) per °C.
Line Voltage Sensitivity: 10ppm/percent line voltage change.
Frequency Output Characteristics
Frequency settings: 50, 60 and 400Hz
Accuracy: ±1%
Adjustment: Vernier adjustment typically ±10%
Synchronization: Can be synchronized to power line
frequency ±3%.
Power Output Characteristics
Power Factor Range: 0 Lag to 0 Lead; 0.1PF steps
Power Accuracy: Power Accuracy
Current Power (±% of V-A Setting)
Setting Factor 50/60Hz 400Hz
<=10.999A 1 0.05 0.12
0.8 to 0.9 0.08 0.16
0 to 0.7 0.12 0.22
>10.999A: 1 0.065 0.12
0.8 to 0.9 0.095 0.16
0 to 0.7 0.135 0.22
Temp. Coefficient: ±0.002% per °C, 50/60Hz.
±0.005% per °C, 400Hz.
Energy (Model 811A and 811AE only)
Range: To 24500 Kilowatt-seconds.
Typical Resolution: 10ppm at 100 Seconds.
Events Range: To 65535 events maximum.
Maximum Event Rate: 4000Hz.

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1.3.2 1.3.2 Models 800AE/811AE
The Following Specifications for power accuracy apply to the Models 800AE and 811AE. For all
other performance specifications for these models refer to paragraph 1.3.1.
Enhanced Mode, ranges of operation
Voltage: 80-130V, 160-280V
Current: 1.1-5.999 Amperes
Max. VA: 690 VA, 80 to 130V; 1380 VA, 160 to 280V
Power Factor: 1 to 0 PF lagging and leading
Frequency: 50-60Hz
Power Accuracy 80-130V; ±50ppm + 0.03 Watts
160-280V;±50ppm + 0.06 Watts
Temperature Coefficient Additional 2ppm per °C at 1 PF
8ppm per °C < 1 PF.

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2. Operating Instructions
2.1 Power Requirements
The Series 800 Calibrators can be operated from an AC power source of 100, 120, 220 or
240 Volts (±5%), 50-60Hz. The selection of line voltage operation must be made prior to connecting
the instrument to the power source by inserting the printed circuit adapter board in the AC receptacle
assembly (located on the rear panel) with the appropriate voltage mark readable. The line fuse is
rated at 4 Amps Slow Blow, 100 or 120 volts; 2.5 Amps Slow Blow at 220 or 240 volts.
A three conductor power cable is provided and when this cable is connected to a standard
three wire outlet the instrument chassis is connected to power systems ground. This feature
prevents the instrument case from assuming voltages which are potentially hazardous to personnel.
In the event that an adapter is used to connect the three wire cable to a two wire outlet the green
(ground) adapter terminal should be connected to the power system ground.
An over temperature switch is connected in series with the AC line and mounted on the rear
panel heat sink. This feature protects the instrument from damage by removing power if the
temperature of the instrument rear panel exceeds limits.
2.2 Installation
The Series 800 Calibrator's standard configuration is bench mounted. Combination handles
and rack mounting ears are available on special order and are interchangeable with the bench
mounting handles. Suitable support must be provided for rack mounts.
2.3 Controls and Displays
Figure 2-1 illustrates the location of all front and rear panel controls, connections and
indicators. Each element of control, display or connection is numbered and a description of the
function of each appears below.
1. Power (Includes ON Indicator)
Switch to energize Calibrator.
2. Record % Deviation
Push switch which holds "% Deviation" reading internally. Sets bit 1 of the status byte on IEEE
488 Interface indicating that the instrument is prepared to transmit "% Deviation" or "volt/ampere
seconds" reading over IEEE 488 bus.
3. Vernier Frequency Control
4. Vernier ON Selector
The vernier selector (a push-push switch) enables the Vernier Control. The Vernier Control
permits variation of the frequency around the selected frequency by approximately ±10%. This
function must be OFF for line synchronization operation,

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5. Frequency Selection Controls
Three controls select 50, 60 or 400Hz output frequency.
6. Power Factor Control, Lead/Lag Selector, Indicator
A rotary switch selects power factor in steps of 0.1PF over the range 0 to 1. Switch selects either
current leading voltage or current lagging voltage. The indicator is illuminator for PF < 1.
7. Operate/Standby Controls
Two independent momentary push switches, red for Operate and green for Standby. Pushing
the Operate control causes excitation at the output terminals. Pushing the Standby control
removes the excitation. Red (for Operate) and green (for Standby) LED indicators display the
existing state.
8. Keypad
Used to enter voltage, volt-amperes, volt-ampere second or number of events values. The
keypad also incudes keys to enter data, reset the calibrator, and initiate the event count mode of
energy testing.
9. Current Output Terminals
These terminals are used to connect the Series 800 Calibrator to the current coil of the unit under
test. The red terminal is high and the black terminal is low. The current output low terminal is
isolated from the voltage output low terminal. Mating connectors are part number PP100GR and
PP100GB, Superior Electric.
10. Voltage Output Terminals
Output terminals High and Low are connected to the voltage coil or input of the unit under test.
Sense High and Low terminals may be used for a four wire connection, or otherwise are shorted
to their respective output terminals. Mating connectors are part number 23.3000-1 and 23.3000-
4, Interlok.
11. Overload Indicator
This LED is illuminated whenever a current is drawn from the voltage terminals or a voltage is
allowed at the current terminals, which is large enough to cause errors.
12. External Sense
This LED is illuminated when a four wire connection is selected.
13. Voltage Display
Displays the three digit value of the output voltage setting which has been entered through the
keypad. Displays ROM revision level immediately after power up.
14. Volt-Ampere-Second/Events (811A only)
Displays the five digit value of volt-ampere-seconds or the number of events setting which has
been entered through the keypad.
15. Current Display
Displays the value of the current setting, computed from the entries of volt-amperes and voltage.
Displays IEEE-488 address code immediately after power up.
16. Kilovolt-Ampere-Second Multiplier Indicator (811A only)
This LED is illuminated when the value of energy is expressed in kilovolt-ampere-seconds.

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17. Current Units Indicator
These LEDs indicate the units of the current in milliamperes or amperes.
18. Volt-Ampere Display
Displays the five digit value of the volt-ampere setting which has been entered through the
keypad. Displays the option code immediately after power up.
19. Key Voltage Status LED
Step 1 in establishing the output setting. When illuminated a voltage value may be entered.
20. Key Volt-Ampere Status LED
Step 2 in establishing the output setting. When illuminated a volt-ampere value may be entered.
21. Select Mode Status LED
Step 3 in establishing the output setting, 811A only. Directs user to either press enter for watt
meter testing, or to key in the volt-ampere-second or event count setting if energy meter testing is
desired. (811A only)
22. Gate Indicator (811A only)
This LED is illuminated between the initiation and termination of the energy time gate, or by
selection, when an event occurs.
23. Error Indicator
Illuminated whenever the following Series 800 limits are exceeded.
Voltages greater than 749 volts.
Currents greater than 50 amperes, or less than 0.011 amperes.
Rear panel fuse out.
Flashes for failure to synchronize.
24. % Deviation Display
Displays the unit under test error in percent of setting as a 2
½ digit decimal readout. The display
is blank for the Deviation "Off" position or if 0 PF is selected.
25. Non-Sinusoidal Current Waveshape Selector (800A only)
Two push buttons, one of which selects a 90ochopped waveform (approximately ½ power).
26. Deviation Range Selector Switches
Three switches selecting OFF and full scale ranges of 0.1% and 1%.
27. Fractional Setting Control and Indicator
This control divides the power setting in fifths, fourths, or thirds. The indicator is illuminated to
show the fractional setting function is in use.
28. Deviation Control
Potentiometer which inserts change in volt-amperes output to measure meter under test error.
29. Connector, IEEE-488 Standard Interface, J46.
30. Line Frequency Synchronizing Switch
Switch to enable or disable output frequency synchronization to the power line (mains) frequency.
Frequency vernier must be in the off position when line synchronization is enabled. Relative
frequency switch must be selected.

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31. Fuse, 250V, 15A Slow Blow.
32. Fuse, 250V, 4A Slow Blow.
33. Fuse, 125V, 4A Slow Blow.
34. Fuse, 32V, l5A Slow Blow.
35. Receptacle Connector (811A only)
For attachment to photo pickup/event input. Mating connector 165-33, Amphenol. (Optional)
36. Line Cord Receptacle
Line Fuse 4A at 120V AC, 2A at 240V AC.
37. External/Internal Voltage Output Sensing
Switch to arrange the voltage output terminals for the two wire or four wire connection.
38. P30 Connector (used on 811A only)
Provides for start-stop energy meter testing. Mating connector 3464-000l, 3M. (Optional)
39. Auto Standby Switch.
40. P38 Connector for arranging Three Phase Operation.
41. P39 Connector for Model 880B/880AE High Current Extender Accessory.
42. Fuse, Voltage Output, .5 Amp, Fast Blow.
Located upper left front corner inside front panel, on relay bracket.
2.4 General Operating Information
There are two principal Models in the 800 Series, the 800A and the 811A. The Model 800A
is used for power meter calibration and testing, whereas the Model 811A has the additional features
required for energy meter calibration and testing. The Models 800AE and 811AE are essentially
identical to their "A" counterparts with the exception that they have the ability to operate in an
enhanced accuracy mode.
WARNING
Before making any connections to the Series 800 Calibrator,
place it in the Standby state by pressing the Standby control.
This will ensure that there is no excitation at the voltage or
current terminals. If this procedure is not followed,
there is a possibility of shock from high voltage.
2.4.1 Model 800A/800AE
The following paragraphs describe the use of the Model 800A calibrator as a wattmeter calibrator.

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2.4.2 2.4.1.1 Entering Voltage
To establish a voltage setting for the wattmeter under test voltage coil, the Model 800A status
LED "Key Voltage" must be illuminated. If it is not illuminated push the reset button located on the
Keypad.
The voltage may now be keyed in. Any integer value from 10 to 749 volts may be entered.
Other values will be ignored and the Error LED will be illuminated. The value of each digit appears in
the Volts display as the keys are pressed. The voltage in the display is applied to the internal circuits
of the Model 800A when the third digit is keyed in and the voltage field is filled. If only two digits are
required (e.g. 15 or 30 volts), the Enter button located on the keypad must be pressed. Thereafter
the Enter Volts LED is extinguished and the Key Volt-Ampere LED is illuminated.
2.4.3 Entering Volt-Ampere
The volt-ampere setting is entered via the keypad and appears in the Volt-Amperes display.
Any integer value may be applied as long as the corresponding current is 50 amperes or less (75
amperes optional). Other values will be ignored and the Error LED will be illuminated. The value is
applied into the internal circuits after the 5th digit is keyed or after the Enter button of the keypad is
pressed. Immediately after the entry of the volt-ampere value, the corresponding output current is
calculated and shown in the Current display.
2.4.4 Applying Excitation
The Model 800A is now ready for application of power to the wattmeter under test. Press the
Operate button momentarily. The red LED above the button should be illuminated. If the excitation
current to the voltage coil or the excitation voltage to the current coil exceeds limits which might
cause inaccuracy, the Model 800A automatically reverts to the Standby state. The Overload LED is
also illuminated. The connections to the wattmeter or its loading characteristics should be checked.
The overload indicator may be illuminated when power is applied to the 800A (due to momentary
transients), but it will be extinguished upon an Operate command under normal conditions.
2.4.5 Power Factor
When not in use the Power Factor selector should be set to 1 PF. When in use any power
factor between zero lagging and zero leading may be chosen in .1PF steps. The Power Factor
selector advances or retards the current with respect to the voltage however it does not affect the
Volt-Ampere display. The Volt-Ampere display shows the power delivered at unity power factor.
2.4.6 Fractional Setting
The Fractional Setting control applies an excitation to the wattmeter which is the product of
the Volt-Ampere display times the setting of the control at 1 PF only. For example, if the Volt-Ampere
display is 1000 Volt-Amperes and the Fractional Setting control is set to 4/5, 800 Volt-Amperes is
applied to the wattmeter under test. That is, the current is reduced to 4/5 of its previous value. The
feature is useful for cardinal point testing of analog meters with non decimal scales.
2.4.7 Deviation Function - Error Measurement
If a wattmeter has an error, it will indicate an erroneous reading. The Deviation controls may
be used to measure the error. Select a deviation scale appropriate to the wattmeter under test.
Adjust the Deviation control so that the wattmeter reads exactly the volt-ampere value displayed on
the Model 800A - or the volt-ampere value times the Fractional Setting value - or the volt-ampere

10
value times the Power Factor setting - if either is used. When this is accomplished the Error display
reads the error in % of setting directly for fractional divider settings and % of output divided by 1/PF
for power factor settings. Note that for Power Factor settings of zero the Deviation function is
disabled; since any error at zero power represents an infinite percentage.
2.4.8 Use as a Voltage Source
The Model 800A may be used to generate accurate AC voltages from 10 to 750 volts for AC
voltmeter calibration. For this purpose place a short between the two current output terminals.
Follow the procedure for entering voltage. Operate may be asserted any time that the entry LED
indicator is in the Key Volt-Amperes field or beyond.
2.4.9 Use as a Current Source
The Model 800A may be used to generate accurate AC currents from 0.011 to 50 amperes
for meter calibration. Follow the procedure for entering voltage and set the voltage to 100 volts.
Follow the procedure for entering Volt-Amperes and set the volt-amperes to the desired current
output times 100. For example, to generate 0.1 amperes set the power to 10 volt-amperes; to
generate 50 amperes set the power to 5000 volt-amperes.
2.4.10 Model 811A/811AE
The Rotek Model 811A may be used to calibrate wattmeters in the same manner as the
Model 800A. All paragraphs of section 2.4.1 apply to the operation of the 811A. In addition, the
Model 811A may be used to calibrate rotating or electronic energy meters.
To accomplish this, the Model 811A has a built-in, crystal controlled, real time clock which
may be applied to generate a precise time interval and thus a precise amount of energy. This internal
clock may also be counted over an externally controlled interval (such as the time between two or
more consecutive pulses from a photoelectric pickup) allowing a precise measure of energy.
How these features are employed depends on the construction of the energy instrument
being inspected. The best means of illustrating the use is through example.
2.4.11 Energy Instruments With Electrical Pulse Output
Instruments such as the Radian Research RM-11, Scientific Columbus SC-10, SC-60, Micro
Joule and the Duncan J-6, among others, produce a pulse train output, the rate of which is
proportional to the applied power. In the case of an SC-10 with a Khof 0.6, the total number of
pulses produced is proportional to the applied energy by the relation of 1000 pulses per 0.6 watt-
hours.
A simple test which calibrates the SC-10 checks this conversion constant. A constant power
of 600 watts is applied to the SC-10 and the 811A will be used to determine the amount of energy
required to generate 10000 pulses. Since,
1000 0 6
0 6 3600
2160
pulses watt -hours
watt -seconds
watt -seconds
=
=×
=
.
.

11
Therefore,
10000 10 1000
10 2160
21600
pulses pulses
watt -seconds
watt -seconds
=
×
=×
=
21600 watt-seconds is the theoretical energy required to produce exactly 10000 pulses. If the SC-10
is in error, it will take more or less energy to produce 10000 pulses. The 811A calculates the amount
of energy actually required to produce 10000 pulses and displays that value in the watt-seconds
display. With this value, the registration error is readily determined. For example a reading of 21610
pulses causes registration error of
%Error %
%Registration %Error
=
−
×=
=− =
21610 21600
21600 100 0 046
100 99 964
.
.%
Similarly, a reading of 21590 pulses causes a registration error of,
% Error
Registration %Error
=
−
×=−
=− =
21590 21600
21600 100 0 046
100 100 046
.%
%.%
This test would last approximately 36 seconds.
To configure the 811A for this test the voltage and current outputs of the 811A are attached
to the voltage and current connections of the SC-10. The "HI" pulse output of the SC-10 is connected
to pin D of J48 on the rear panel of the 811A. Switch S-3 on the inside Rear Panel assembly must be
set as shown in the cutaway on Figure 2-4. This switch is set to this position at the factory. The
movable mini jumper must be moved so that the 4.7 kOhm resistor to +5 VDC is connected. When
S-3 is in the correct position the EVENT/GATE mode LED is illuminated whenever a pulse occurs.
Reset the 811A, then enter 120 volts. Then key 600 volt-amperes and press enter to set
120 volts, 5 amperes, and 600V-A. Ensure that the Power Factor control is set to unity. Connect the
SC-10 to the voltage and current outputs of the Model 811A. Next enter the number of events or
pulses to be counted, which is 10000 in this instance. Press Operate to apply power to the SC-10.
When the SC-10 has stabilized, the Event Count button is pressed to begin the test. The pulses are
counted and the event count display will indicate the number of pulses left to be counted. When
10000 pulses have occurred, the event count display will contain a value which is the energy
delivered in units of watt-seconds. This test is conducted "on the fly" and can be repeated by
pressing enter, then keying the desired count of 10000 again, etc. Other voltages, power levels,
pulse counts and power factor may be employed as necessary. The maximum input pulse rate is
4000 pulses per second.

12
2.4.12 2.4.2.2 Rotating Instruments With No Pulse Output
This category of meters includes consumer service meters (Revenue Meters). If the
instrument has no pulse output then an optical sensor is utilized to sense disk rotation. This sensor
generates a pulse which is used in place of the pulse output of the SC-10. Otherwise the test is the
same as that described above.
The optical sensor consists of a light source and a light detector. In one type, the light source
illuminates a portion of the meter wheel and the light is reflected from its surface back to the light
detector. The surface of the wheel at the index point is non reflective interrupting the light as the
index point passes by the light detector. Thus, once per revolution (or in some instances more often)
the light detector senses the short interruption of the light source.
Other sensors operate with meter wheels which allow transmission of light through a small
hole in the wheel at the index point. This type senses a short pulse of applied illumination.
The light source can be an incandescent lamp or light emitting diode (LED). A modulated
LED source can reduce the interference from high levels of ambient light. The pickup can be a
simple photo-resistor. If the source is modulated there must be a demodulator after the pickup to
benefit from this technique. The output may be a TTL level signal. In the 811A a level of < +0.8V DC
(low state) to +2.0V DC (high state) must be applied.
Optical sensors are commercially available or may be ordered through the factory.
Some sensors operate from the AC line voltage while others require only excitation for the
light source. The Model 811A has provisions to adapt to a wide variety of sources through
connections on J48, settings of S-3 on the inside rear panel and selectable resistance values on the
rear panel assembly to match impedance's. Refer to Figure 2-4.
If the sensor has a incandescent 5 to 6.3V lamp and a photo-resistive pickup, the 5V
regulated supply on pin C of J-48 may be used for lamp excitation. The photo-resistive element may
be either a high or low impedance device. If it is a high impedance device it will be matched best by
resistors R33 or R34, and if low impedance R30 or R31. Select one of the resistors by moving the
mini-jumper connector (on rear panel p.c. board) to the appropriate resistor. With excitation on the
lamp and the lamp installed to provide maximum and minimum illumination of the photo element, the
voltage swing on the emitter of transistor Q13 is measured. The optimum matching will cause the
greatest swing with a low value of < +0.8V and a high value of +2.0V DC. If the photo pickup
provides a TTL level output the mini-jumper should be connected to R4 which is the highest value
resistor. If the pickup provides an open collector or switch closure at the index point, such as the SC-
10 and many of the electronic transducers, then the 4.7K resistor, R32 to +5V DC, should be
connected by the mini-jumper.
Switch S-3 inverts the internal TTL signal so that in all cases the occurrence of the index
point of the meter's wheel or pulse input creates an 'ON' condition of the EVENTS/GATE MODE
indicator on the front panel. Proper operation will occur in any instance but it is much better to see
the pulsing 'on' of an indicator than the reverse.

13
2.4.13 2.4.2.3 Rotating Instruments, Fixed Energy
This technique is usable with standards such as the General Electric Co. IB -10 and the
Scientific Columbus SC-10 meters. In this mode the Model 811A is set to a precise apparent energy
at the rated wattage of the meter. The energy can be selected by the user to register any number of
full turns of the indicating wheel or counts of the register. After connecting the unit under test to the
Model 811A, the Model 811A is placed in the Operate state. The voltage coil of the standard meter
is then disconnected and the register of the meter is reset. With current applied the unit under test is
allowed to 'warm up' though with no voltage applied the register does not indicate anything. When
the voltage coil of the standard is switched on to the Model 811A via external means, such as the
pendulum switch normally supplied with IB-10 type standards, the timing to generate the precise
energy is automatically started. This is accomplished by connecting the "load applied" output signal
to either the "start VAS time-out" or "KVA SEC time-out" (see paragraph 2.4.2.4 for specific
connections on connector P30). At the end of the timing period the output of the Model 811A is
automatically removed. The indicator of the meter under test may then be read to determine
performance.
NOTE
The contacts of the pendulum switch should be bypassed with a capacitor
(such as a 0.01µF 1.5kV disk) to prevent switch bounce from disturbing the operation
of the Model 811A. Otherwise the 811A will revert to the Standby state immediately
after Operate is pressed.
After a test has been completed, the same or new energy data must be entered into the
Model 811A. The same data can be re-entered by pressing the enter key twice.
The load applied signal has been factory adjusted to trigger at 4VA for 120V settings and
8VA for 240V settings. For instruments having a high input impedance, such as a Model SC-10, an
appropriate load resistor (2.5K 120V, 4.7 K 220V) must be attached to the voltage input terminals on
the instrument under test. (See Figure 2-6).
The Auto Standby Switch, located on the calibrators rear panel, must be set to the 'auto'
position (up) to enable this mode of operation and the load applied signal on P30 must be jumpered
to the start VAS or KVAS line time-out. In all other situations the auto standby switch should be left in
the 'down' state. See paragraph 2.4.2.4 for details.
Assume, as an example, a test of such an instrument at 120 volts, 5 amperes, 0.5 PF
lagging, where the register is to be checked at 10 turns. The watt-hour constant (Kh) is 0.6 watt-
hours/revolution. or 2160 VA-seconds/revolution. Ten complete revolutions of the dial will thus
require 21600 VA-seconds of energy. At a power factor of 0.5, however, this represents 43200 VA-
seconds. Before beginning the test be certain to connect P30 pins 22 and 24.
To enter the settings it is best to begin by resetting the 811A. Then key 120 volts followed by
600 VA to enter the VA setting. Set PF to 0.5 lagging. Next key 43200 VAS; the last digit will enter
the value automatically so it is not necessary to press the enter key. Ensure that the pendulum
switch is open, then press the 811A Operate Control. This applies the current of 5 amperes to the
current winding of the instrument to allow 'warm up'. After a suitable 'warm up' (8 to 10 seconds
minimum for the 811A) the pendulum switch is closed. The 811A will continue to power the
instrument until precisely 43200 VAS are furnished and then the 811A will remove power.

14
The registration of the instrument may be calculated in the following manner:
%Error Meter Reading Expected Reading
Expected Reading
%Registration %Error
=
−
×
=−
100
100
The test may be repeated by:
1. Opening pendulum switch, reset instrument under test.
2. Press enter key twice (to enter VA and VAS).
3. Assert Operate 811A.
4. Close pendulum switch.
2.4.14 Availability of Additional Signals
Additional signals are available at connector P30, located at the rear of the unit. These
signals and their pin connection, are as follows.
Pin # Signal Label Logic
16, 18, 20 +10 unregulated
29, 3l, 33 Logic ground
35, 37, 39 Logic ground
22 Load applied
38 + Energy gate
40 - Energy gate
24 start VAS time-out Input negative assertion
26 start KVAS time-out Input negative assertion
Example: For automatic start-stop testing of rotating watt-hour meters (i.e. G.E. Model IB-10)
connect pin 22 of P30 to pin 24 for VAS time-out or to pin 26 for KVA SEC time-out. At the end of the
time-out the Model 811A will automatically go into the Standby mode and the Enter Volts and Error
light will be illuminated. This is to alert the operator that the Energy information has to be re-entered.
By pressing the "Enter" key two times the 811A is now ready for a new test.

15
3. Theory of Operation
3.1 Introduction
The Series 800 consists of two sources for generating Voltage and Current independent of
each other, with a means for controlling the phase relationship between them. The three separate
functions of the 800 Series are:
•Voltage
•Current
•Power Factor
The Series 800 is a microprocessor based system which, in conjunction with logic decoding,
provides an interface between the front panel controls and the three functions listed above. The
basic configurations for each section are described in this paragraph. The following paragraphs
describe the detailed operation of each section and logic interface.
3.1.1 Voltage
Figure 3-1 shows the arrangement of components for the generation of the AC voltage
output. The basic components in this block diagram are:
•A precision source of DC voltage, the Voltage Reference.
•A precision D to A converter, the Voltage Attenuator.
•An operational amplifier integrator.
•A voltage controlled oscillator.
•The Post Attenuator.
•A precision operational amplifier rectifier.
The voltage controlled oscillator injects a signal via the post attenuator to the power amplifier
which in turn drives the primary of the output step-up transformer; the selected voltage is then applied
to the output terminals. The precision rectifier senses this voltage at the sense terminals via the
appropriate range resistor. The rectifier output injects a current to the summing junction of the
operational integrator. This current is compared with the current injected by the DC reference, D to A
converter combination. The output of the integrator assumes a value that establishes an amplitude
from the voltage controlled oscillator such that the average of the currents injected into the summing
junction are equal and opposite; thus leveling the oscillator for the correct output voltage.
The power amplifier can supply sufficient current to cause an error due to lead drop,
particularly on low impedance meters. The points that sense voltage (i.e. the connection to Rf) are
connected to Sense High and Sense Low. These terminals are available for four wire measurement
to eliminate lead drop errors. For most meters the sense and output terminals are connected
together for four wire configuration. The 800 Series is placed in the External Sense mode via S20 on
the rear panel of the 800A/811A.

16
CAUTION
To prevent an overload condition, the external
four wire connections should be made prior to
switching to the external sense configuration.
3.1.2 Current
Figure 3-2 shows the arrangement of components for the generation of AC current output.
The basic components in this block are:
•Precision source of DC voltage, the I Reference (this is a separate Reference from
that referred to in 3.1.1 above).
•Voltage controlled oscillator with self contained amplitude control, similar to that in
3.1.1 above.
•An AC D to A converter, the I Attenuator.
•Power amplifier.
•Precision current shunts.
•Sense amplifier system.
•Current source.
The I oscillator, which has a self contained amplitude control circuit similar to that of the
voltage oscillator described in 3.1.1, maintains a constant amplitude of 7.0711 volts. This signal is
injected to the scaling amplifier which consists of the I Attenuator and AR3. The output of the scaling
amplifier (which has a value of 0.5V to 5V) is then fed to the current source via AR4. The current
source (which consists of AR9, Q1 and the output stages) then feeds the current shunts. The current
then is fed to either the output terminals or to the current transformer T5 (10-50A). AR8 also senses
the voltage developed across the current shunts and feeds it back to AR4 which provides a correction
signal to the current source so that a 1 volt full scale voltage is maintained a cross the current shunts
independent of the voltage at the output terminals.
3.1.3 Phase Control
Phase control is accomplished by measuring the area under a sine wave between axis
crossings of the current and voltage waveforms. The area is caused to be equal to the power factor
input by summation at the input of an operational amplifier integrator. The integrator controls the
relative phase of the I oscillator.
This is illustrated in Figure 3-3. The I oscillator output and the Voltage output are sliced to
detect their axis crossings. The phase sensor generates a pulse train, in which the pulse length is
precisely the phase delay or advance. If the current lags the voltage, the train appears in the LAG
line, otherwise the train appears on the LEAD line. These trains close switches which apply part of
the I oscillator output or its inverse to the integrator input which is then balanced against the decoded
lead or lag PF input voltage.
3.2 System Operation
The system operation is described by reference to three drawings 08-800-002 1/2/3, which
show the components, connections and waveforms for the voltage, current and phase functions.