VLF HIPOT TESTER USER’S MANUAL Content I. Product Advantage--------------------------------------------------.1 II .Technical parameters-----------------------------------------------2 III. Attentions-----------------------------------------------------------4 IV. Instrument structure ---------------------------------------------- 4 V.Wiring methods------------------------------------------------------9 VI. How to test cables-------------------------------------------------12 VII. How to test generator--------------------------------------------14 VIII. Operation procedure--------------------------------------------17 IX. Operating Instructions of Discharge Rod----------------------26 X. Printer Instruction--------------------------------------------------27 XI. Accompanied accessories----------------------------------------29
Transcript
VLF HIPOT TESTERUSER’S MANUAL
Content
I. Product Advantage--------------------------------------------------.1
II .Technical parameters-----------------------------------------------2
III. Attentions-----------------------------------------------------------4
IV. Instrument structure ---------------------------------------------- 4
XI. Accompanied accessories----------------------------------------29
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I. Product Advantage
1. VLF means ‘Very Low Frequency’ and 0.1Hz to 0.02Hzis considered to be very low frequency.
2. VLF HV Generator is suitable for testing cables,transformers, switchgear,rotating machinery,and otherelectrical apparatus.
3. The product combines modern advanced digital variablefrequency technology and micro computer control together,therefore, it can realize the full automatic voltage boost,stepdown, measurement and protection as well as the manualintervention in the process of automatic voltage boost. Thefull electronic design ensures the small size and light weight.The big LCD screen ensures the clear and visual display, andcan display the output wave form. The printer outputs testreports. In addition, the product has features as follows:
★ Data of current, voltage, wave form can be directlysampled at high voltage side, so the data is real andaccurate.
★ Overvoltage protection: If the output exceeds the set limitof voltage, the instrument will shut-down to protect itself,the actuation time is less than 20ms.
★ Overcurrent protection: it is high-low voltage dualprotection in the design, the accurate shut-downprotection can be made according to the set value at highvoltage side; If the current on low voltage side exceeds
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the rated current, the instrument will take shut-downprotection, the actuation time are both less than 20ms.
★ A high voltage output protective resistor is provided inthe voltage boost body in the design and this eliminatesthe need of additional protective resistor connectedoutside.
★ True sine wave output.
★ Storage of test results for later retrieval and print.
★ AC testing does not degrade good cable insulation.
★ Harmful space charges are not injected into the cableinsulation.
★ No traveling waves are generated during testing.
★ Rugged and reliable design less prone to failure fromtransients.
6. Positive and negative voltage peak errors: ≤3%.7. Voltage waveform distortion: ≤5%8. Construction: In two units: Controller and Booster..9. Ambient conditions of use: temperature Indoor andoutdoor : -10ºC to + 50ºC.10. Humidity:≤85%
1. Power supply requirement: AC 220V 50/60Hz or AC110V 50/60Hz (as per buyer’s requirement before booking),stability of frequency: fluctuation less than 0.5%
2. When using it, it is prohibited to boost voltage withoutload, or to connect with resistive load.
3. When using it, the capacitance of the DUT should notexceed the rated capacity of the instrument. The overlowcapacitance of the DUT will affect the output wave form. Ifthe capacitance is less than 0.04µF, the instrument cannotoutput normally, at this time, please paralleling connectionwith a 0.04µF compensating capacitor supplied by us (Free),then the equipment can output normally.
4. Before testing, please pour a litte dielectric oil(transformer oil) into the tube (see below picture) , makingthe tube almost overfill oil when insert the white inputconnector. May demage the equipment if it is dry in tube.
Inpour transformer oil White Connector
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IV. Instrument structure
1. Structure: the instrument includes 2 units: Controller +Booster
(1) 1 controller + 1 booster (as shown in figure 1): theinstrument has only 1 controller and 1 booster when the ratedvoltage is less than or equal to 50kV, the wiring method of 1booster is called "Single connection" or "single" (as shown infigure 6-1 & figure 6-2).
Figure 1
(2) 1 controller + 2 booster (as shown in figure 2): theinstrument has 1 controller and 2 booster when the ratedvoltage exceeds 50KV, the wiring method of 2 boostertogether is called "Connection in series" or "series" (asshown in figure 6-2).
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Figure 2
Each booster of 2 boosters can be respectively used to testDUT according to the requirements in the methods of series,for example:1x 80KV instrument includes 1 x 30KV and 1 x 50KVboosterit is called "Series" when both of 2 booster is jointly used totest rated voltage 80KV (30KV +50KV); it is also called"Single" when it is separately used to test 30KV or 50KVvoltage.
3. Controller panel schematic
Panel of Single Connection
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Panel of Connection in Series
Figure 3
Schematic of parts and function description in figure 3:
(1) “Ground”: Grounding terminal, which is connected withground when being used.(2) “Output”: The output multi-core socket, which isconnected with the input multi-core socket when being used.(3) “Contrast”: The contrast adjusting knob, which is usedfor the adjustment of contrast of the LCD.It will automatically adjust contrast if there is no adjustingknob on the panel.(4) “Function key”: The function is prompted atcorresponding location at prompt column on the display.(5) “AC 220V”: The power input socket with inbuilt fusetube.(6) “Power”: power switch with inbuilt indicator light, whichilluminates upon open and extinguishes upon close.(7) “Printer”: print the test report(8) “LCD”: It displays test data and output wave form.
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4. Schematic of booster structure
Figure 4
5. Schematic of LCD display
Figure 5
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V. Wiring method
Wiring Method of Single booster:
The method of wiring shall be according to figure 6-1 &figure 6-2 if the rated Voltage is less than or equal to 50kV.When only 1 booster of the instrument will be used in themethod of series, it especially needs to click"Singleconnection" or "Single" selection at Column of ParameterSetting after the equipment is power on (as shown in figurebelow).
Figure 6-1 (30KV Test Wiring drawing)
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Figure 6-2 (50KV Test Wiring drawing)
Wiring Method of connection in series
The user should adopt the method of connection in serieswhen the rated Voltage exceeds 50kV. After completingwiring according to figure 6-3,click"connection in series" or "Series" selection (as shown infigure 9) at Prompt Column of Parameter Setting when thepower of equipment is put on.
1. Removing the electrical equipments connected with testcable.
2. Measuring insulation resistance of each cable phase with aMegohm meter,then VLF withstand test can be taken if testcable is considered to be in good condition.
3. Test peak voltage formula: Ｕmax＝3Ｕo,
Ｕo: A fixed value of cable phase. For example: A ratedvoltage 10kV cable, single-phase rated voltage: Ｕo＝10÷ 3 kV＝5.774kV,so the test voltage peak value: Ｕmax＝3Ｕo＝17.32kV.
4. Test time: according to test requirements. For instance:A new cable test should be tested 60 minutes.5. Each phase test can be measured. Cable test can be
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synchronously taken after paralleling cable cores of 3-phases if Cable capacitance doesn't exceed the ratedcapacitance of VLF Tester.
6. Cable test connection according to the method shown inFigure 6-3. supplying the power, setting the test frequency,time and voltage and high side over-current protection value,over-voltage protection value, and then start to boosting test.During boosting,high-voltage loop should be closelymonitored, meanwhile, surveying whether cable hasabnormal noise or not. The equipment will begin to recordtest time and test voltage reading value when it goes to thetest voltage.
7. When test time is up, the instrument will automatically beshutdown. It is considered to be passed the test if there is nodamaging discharging.
8. Please stop the equipment immediately if finding thefollowing things during boosting: output waveform distortionabnormally, abnormal increasing strong current, voltageinstability, cable peculiar smell/smoke/abnormalnoise/flashover.
If these phenomena are caused by poor cable insulation, it isconsidered that the withstand test failed; should be clean anddry handling test materials cable, then testing if determiningtest cable caused by air humidity or surface dirt and others.
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Figure 6-4 (Schematic of Cable test wiring method)
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VII. How to test generator
A. Comparison Table of Generator Capacity
B. Testing Generator methods:
1.Generator connection method as shown in Figure 6-5.
2.In accordance with the requirements of the regulations, thetest voltage peak can be determined to follow the formula:
Ｕmax＝ 2 βＫUo,
Umax: 0.1Hz peak voltage (kV);β: 0.1Hz and 50Hz voltage equivalent factor, usually
taking 1.2;K: usually take 1.3 to 1.5, generally take 1.5;Uo: generator stator windings rated voltage (kV), for
example:A rated voltage 13.8 kV generators, VLF test voltage
peak value is:Ｕmax＝ 2 ×1.2×1.5×13.8≈35.1(kV)
Generatorof Thermal Power
Generatorof Hydropower
GeneratorCapacity（MW）
200 300 600 85 125-150 300 400
MonophaseGroundCapacitanc（µF）
0.2-0.25
0.18-0.26
0.31-0.34 0.69 1.8-1.9 1.7-
2.52.0-2.5
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3.It's considered to pass withstand test if there is nofollowing things during withstand test: no abnormal noise,peculiar smell, smoke, data show instability. In order tobetter understanding the situation insulation, should be ascomprehensive as possible monitor the surface insulationstate, especially air-cooled units. Experiences tell you thatthe appearance of surveillance can discover the generatorinsulation abnormal phenomena such as surface corona,discharge and so on.
Figure 6-5 (Schematic of Generatorconnection method)
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VIII. Operation procedure
(1) Open, close and reset
After completing the wiring of all the circuits in the methodmentioned above, the power switch can be put on. Theinstrument will automatically enter into the limit settinginterface as shown in figure 7 when the microcomputer iselectrified and reset.
Note: The power shall be shut-down under wiring、removalof lines or temporary non-use of the instrument. The powersocket is provided with fuse tube, in case there is no displayon the screen upon start-up, the first check shall be made onthe fuse tube. The rating of the replaced tube shall beaccording to the data in Table 1.
(2) Limit parameter setting
Figure 7 (Limit setting interface)
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On limit setting interface as shown in figure 7, the user canset output frequency, test time and voltage, overcurrentprotection value on high-voltage side and overvoltageprotection value according to test requirement. Themodification methods are as follows:
(A) Click “Selection” key, and the special selective box canbe shifted among the parameters in cycle. The selectedparameters can be modified through “datamodification”(change) key.
(B) Click “Change” key and the parameter selected by thespecial box can be modified in cycle according toincremental method.
★ There are three options for the frequency: 0.1, 0.05 and0.02. It specified the output frequency of the instrument.The unit is Hz.
★ Timing modification scope: 0-99 mins. It specified thetime of test. The unit is minute.
★ Range of test voltage is from zero to rating, unit is kV. Itspecified the test voltage to be boosted. When the voltageof the instrument reaches to this set value, it will stopboosting, maintain at this peak value and output uniformamplitude sine wave.
★ The setting scope of current protection value is from 0 tothe rating, the unit is mA. It specified the upper limit ofthe current of the sample. If the current exceeds this set
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value, the instrument will automatically cut off the outputand shut down.
★ The voltage protection value is from 0 to the rating, theunit is kV. It specified the upper limit of the voltage ofthe sample. In case the voltage exceeds the set value, theinstrument will automatically cut off the output and shutdown.
★ "Single" and "Series" connection. Selecting "Single"means that one of two boosters will be respectively used(Setting method as shown in figure 8); Selecting "Series"means that both of 2 boosters will be jointly usedaccording to requirements (Setting method as shown infigure 9)
Figure 8
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Figure 9(C) Click “Return” key, the instrument will enter into voltageboost standby interface as shown in figure 10.
(3) Standby interface
Figure 10 (Standby Interface)
The Standby Interface has three functions as follows:
(A) Click “Boost” key, the instrument will enter intoautomatic boost procedure.
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(B) Click “Setting” key, the instrument will return to set limitsub-interface as shown in
figure 7 to re-modify parameter.
(C) Click “Check” key to check the test data in the last ninetimes.
(4) Automatic boost
Click “Boost” key as shown in Figure 10, the instrument willenter into boost test under microcomputer control accordingto the procedures as follows:
On self-check, the instrument outputs a detecting voltage tocheck the system. If the condition is normal, the instrumentwill boost. If the condition is abnormal, the instrument will
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shut-down, and the prompt message “load unconnected” willappear as shown in figure 11, in case the booster or thecapacitor sample (DUT) is not connected or there is a failurewith the instrument.
(B) Boost
Figure 12
Figure 13
If the self-check has passed successfully, the instrument willautomatically enter into boost status, as shown in Figure 12.
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It will take several cycles to increase the voltage to the setvalue for the instrument. During boost process, click “Pause”key as shown in Figure 12 can pause the boost process, andthe instrument will have uniform amplitude output. At thesame time, the key will be automatically turned into “boost”key, which can be re-clicked to continue the boost processuntil the set voltage of the instrument is reached. The twofunctions are alternative. Click “Timing” key in boostprocess, the instrument will begin timing process, or you canwait until the voltage is increased to the set value, then theinstrument will have automatic timing. At the same time the“timing” key will be turned into “Stop” key as shown inFigure 13.
(C) Voltage fine adjustment
In case the output voltage cannot satisfy the requirement,click “Up”(slight increase) or “Down” (slight decrease) keysto adjust the voltage. After each click, an observation of atleast one cycle shall be made, then make the adjustment untilachieving satisfied condition.
(5) Shut-down
Two shut-down modes are available for this instrument:
★ Timing shut-down: the instrument will shut down atspecified set time.
★ Manual shut-down: click “Stop” key can stop theinstrument.
These two shut-down methods are normal ones. After shut-
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down, the prompt interface “Test Passed” will appear asshown in Figure 14. In general, it will be considered thatthe instrument has passed the test if there is no electricaldischarge 、 overvoltage or overcurrent protection on theDUT (sample).
Figure 14
★ Additionally there are two abnormal shut-down:overvoltage and overcurrent protective shut-downfunctions. In case of shut-down, the prompt interface willappear as shown in Figure 15.
After start-up shut-down command, the instrument willautomatically cut off the output, then execute the historicaldata storage.
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Figure 15
(6) Print
Click “Print” key according to tips as shown in Figure 14,the user can print the data shown on the display as test report.On historical data checking status, click “Print” key, the usercan print the historical data as shown on the screen.
(7) Historical data check
Data displayed on condition of timing shut-down, click key“Stop”, overvoltage and overcurrent protective shut-downwill be stored by the instrument as historical data. Data oflast nine times will be stored, and previous data will beautomatically eleminated. Click the “Check” key as shown inFigure 10, the user can check the historical data of tests in thelast nine times.
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IX. Operating Instructions of Discharge Rod
It is necessary to discharge with discharging rod afterfinishing withsand testing, and then the wires can beremoved.
Usage Method of Discharg Rod:
1. Pull out the extension pole completely.
2. Insert the Banana Jack into the hole of the Rod. ConnectEarth cable clip to a good Earth Terminal. Then Dischargethe electrified body.
3. Re-connect the Earth cable with the top of Discharge Rod,then discharge the electrified body completely.
4. For discharging the DUT/cable under test, bring the tip ofthe rod in close proximity. A spark should take place and itshould die out.
5. Caution: in case the spark does not die out, never touch thetip directly to DUT/cable under test.
outside diameter40mm，inner diameter12mm● Power supply: DC5V±5%, average current 2A, peakvalue current 5A.● Indicator : SEL (on/off line selection); LF: (paperfeeding); red light is on/off line indicator, green light ispower indicator.
Open Button
SEL (Red Indicator)LF (Green Indicator)
Figure 16 Panel of Printer
2. Loading paper :
Operation of loading paper for printer is very easy. It is notnecessary to take off the printer from the panel. Open thefront cover simply ,take out the paper just as Fig 17-1 showsand then load the paper as Fig 17-2 shows, close the frontcover as Fig 17-3 shows.
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Figure 17-1 Open front cover
Figure 17-2 Put in paper roll
Figure 17-3 Close the cover
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Notice : Let the paper spread out of the paper exit or elseit can not print.
Before loading the paper, must make sure the thermal coatof the paper is on the top, then put the paper into the paperdepot. If the thermal coat is not on the top, the printer cannot print out. If the paper has departed from the correct way,please open front cover again, then adjusting the position ofpaper.
