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Watt/VAR Instruments 

 

 

 

 

 

 

Watt/VAR User Manual 

2-Element, 3-Wire 

 

 
 
 

 

 

 

 

 

 

 
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

August 7, 2009 
ML0030 Document  Revision B 
© 2009 by Bitronics, LLC 

 
 

 

 

 

 

 

 

 

 

(Includes 0-1mA Transducer Outputs) 
 
 
  No.  QTWIE2   

WATT/VAR METER 

  No.  WTWIE3   

WATTMETER 

  No.  RTWIE3   

VARMETER 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
 

 
 
 
 

Содержание QTWIE2

Страница 1: ...Instruments Watt VAR User Manual 2 Element 3 Wire August 7 2009 ML0030 Document Revision B 2009 by Bitronics LLC Includes 0 1mA Transducer Outputs No QTWIE2 WATT VAR METER No WTWIE3 WATTMETER No RTWIE3 VARMETER ...

Страница 2: ...rent and Potential Transformer Board CT PT Board 4 2 4 Power Supply Board PS Board 4 2 5 Analog Processing Board AP Board 4 2 6 Microcontroller Board MCU Board 5 2 7 LED Display Board LED Board 6 3 0 INSTALLATION 7 3 1 Initial Inspection 7 3 2 Power Requirements 7 3 3 Overcurrent Protection 7 3 4 Mains Disconnect 7 3 5 Instrument Mounting 7 3 6 Surge Protection 8 4 0 FIELD ADJUSTMENTS 9 4 1 Rescal...

Страница 3: ...d by Bitronics the protection provided by the equipment may be impaired WARRANTY AND ASSISTANCE Products manufactured by Bitronics LLC are warranted against defects in materials and workmanship for a period of thirty six 36 months from the date of their original shipment from the factory Products repaired at the factory are likewise warranted for eighteen 18 months from the date the repaired produ...

Страница 4: ......

Страница 5: ...of input signal levels WATT VAR meters are modular in design with push button rescaling to display primary values when using any standard current and voltage transformer Rescaling can be done in the field in a matter of minutes without removing the instrument from the panel or the need for any calibration equipment Physical dimensions are the standard 4 round case with an overall length of 6 5 inc...

Страница 6: ...d by CT PT ratio Scaling User selectable using internal CT PT tables Accuracy 0 25 Class ANSI Std 460 1988 Signal Frequency 50Hz to 400Hz Including Harmonics Current Output 0 to 1mA into 10K ohms or less 0 4 ripple p p or less Calibrated at 1000W at meter input Overload to 2mA into 5K ohms or less Power Requirements 115 Vac 20 6 VA 230 Vac or Universal AC DC optional Fuse 1 5 Ampere non time delay...

Страница 7: ...he need to remove the meter from the panel or to remove the meter from service see section 4 4 Detailed descriptions of each of the boards can be found in the following sections 2 2 Input Signal Connections The WATT VAR Meters have six independent signal inputs one current and one voltage for each phase being measured Current and voltage signals are connected directly to 10 32 brass studs on the r...

Страница 8: ...500Vac between the inputs and any output 2 4 Power Supply Board PS Board The power supply circuit is a conservative conventional design Low drop rectifiers and a low drop out solid state regulator minimize internal power dissipation Filter capacitors are operated at a fraction of their voltage and temperature ratings and should provide years of trouble free service under extreme environmental cond...

Страница 9: ...stored in the EEPROM on the analog board are read by the MCU and used to compensate for gain and offset of each output channel This technique provides stable calibrations for the output s Additional circuitry converts the output of each DAC to the 0 to 1 milliamp current This additional circuitry is powered from a 15volt and a 15volt supply also located on the AP module The outputs have a 10volt c...

Страница 10: ...en segment decoder driver chip which accept serial data from the MCU and decodes the data into the seven segment and digit select outputs necessary for the multiplexed display The high current cathode drive is provided by an MC1472 driver for each pair of digits On power up or any other time the MCU is reset a display test will be conducted that displays 1 8 8 8 on the top display followed by 1 8 ...

Страница 11: ...nstrument The power supply and regulators provide constant dc power to the modules independent of variations in ac supply voltage over this range If the supply voltage drops below the point at which the regulators can function properly the watchdog timer will cause the displays to flash as described previously 3 3 Overcurrent Protection A UL listed 1 5 Ampere non time delay M fuse is to be series ...

Страница 12: ...s of the instrument The GREEN lead of the MOV assembly should be connected to a good earth ground In most instances this is usually accomplished by connecting the GREEN lead to the indicated front mounting stud This mounting stud is a safety ground for the instrument and should be connected to a protective earth circuit refer to Figure 3 Although the Line to Ground capacitors are 3kV and UL rated ...

Страница 13: ... CT or PT will be shown on the top display All CT ratios are assumed to have 5 amps as their secondary maximum outputs Therefore 10 0 on the display corresponds to a 10 5 CT PTs are represented by a ratio to 1 so 20 0 on the display would correspond to a 20 1 PT Powers of ten can also be set as the decimal point moves from left to right by using the select button 3 Index through the available CT P...

Страница 14: ... relay ratio 1 20 12 0 120 1 40 14 0 140 1 50 15 0 150 1 73 17 3 173 relay ratio 1 75 17 5 175 1 80 18 0 180 2 00 20 0 200 2 31 23 1 231 relay ratio 2 40 24 0 240 2 50 25 0 250 2 51 25 1 251 relay ratio 3 00 30 0 300 3 46 34 6 346 relay ratio 3 50 35 0 350 4 00 40 0 400 4 35 43 5 435 4 50 45 0 450 5 00 50 0 500 5 77 57 7 577 relay ratio 6 00 60 0 600 6 35 63 5 635 6 64 66 4 664 6 93 69 3 693 relay...

Страница 15: ...o decrease the indicated measurement NOTE Because these WATT VAR meters are a full 2 elements the instrument can be calibrated with a single phase source all current inputs should be connected in series and all potential inputs should be connected in parallel 5 Remove the screwdriver and replace the calibration seal 6 Replace gasket front cover and four cover screws The 0 to 1mA output will track ...

Страница 16: ...e CT and or PT ratios The transducer outputs are still functional and accurate Calibration constants for the CT PT Board are in error The display and the transducer output are reduced in accuracy to approximately 3 Calibration constants for the Analog Processing Board are in error The display and the transducer output are reduced in accuracy to approximately 3 The watchdog timer is attempting to r...

Страница 17: ...input quantity exceeds the range of the instrument Both display and transducer output accuracy reduced by an amount depending upon the degree of over range The microcontroller has detected a fault in program memory and is attempting to restart itself Microcontroller will force transducer outputs to 2ma 0 1ma out or 2ma 4 20ma out Instrument cannot read any signals Microcontroller will force transd...

Страница 18: ...cated at the top of the module pull gently on the bail and the Electronics Module will pull out a slight rocking motion may be required Be careful not to bend any of the connector pins in the Base Module CAUTION when the Electronics Module is removed with the instrument powered instrument power 115Vac or 230Vac is present on the circuit boards that remain in the Base Module DO NOT touch or insert ...

Страница 19: ...4 HI and LO are marked on the inputs Does polarity matter Yes Correct wiring with proper polarity is essential for proper operation 5 Can I put WATT VAR meters in an outdoor cabinet Yes Many Bitronics meters are installed that way The temperature range of 20C to 70C covers most applications The case is gasketed but not waterproof so it must be placed within an enclosure that provides ingress prote...

Страница 20: ...Figure 4 Typical connection diagram for 2 Element Watt Var Watt Var Meters ...

Страница 21: ...1 Brodhead Road Bethlehem PA 18017 610 997 5100 Fax 610 997 5450 www novatechweb com bitronics Revision Date Changes By A 01 30 2009 Update Bitronics Name Logo E Demicco B 08 14 09 Updated logos and cover page MarCom C ...

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