Description

“NTPL” MAKE CONSTRUCTION & MODULER TYPE 70KV-3A AC/70KV-10mA DC HIGH VOLTAGE TEST SET SERIES: ACDHVMT-CR TYPE: 070K03A-070K010m

“NTPL” make AC DC High Voltage Test Set  is  suitable  for  applied  voltage  test  on  transformers,  motors, switchgear etc. for which the test parameters are within the technical scope of output  of  the test set. The test set is capable of giving continuously variable High voltage from zero to 70KV AC /zero    to 70KV DC.

Input         :     415Volts, 50Hz, 1 Phase (between 2 phase of 3 phase system) AC.

A)  AC MODE

Output            :     Continuously variable 0 to 70KV AC rms. Capacity :           3A max. at HT side.

Duty Cycle      :     Intermittent duty cycle, i.e., 5 mins. ON, 10 mins. OFF.

• Output voltage variation: By means of motor driven
• rate of rise of output voltage 2KV/sec.
• Over load Tripping adjustment: At 500mA, 1A,2A & 3A
• Over Voltage Indication & Interlock Protection

B) DC MODE

Output           :      Continuously variable from 0-70KV DC.

Polarity: Negative Capacity :     10 mA max. at HT side.

Duty Cycle      :     Intermittent i.e. 5mins. ON/10mins. OFF.

• Over load Tripping adjustment: At 10mA
• Over Voltage Indication & Interlock protection

The above test kit will be in multiple units i.e.

1.Integrated Control & Measurement Unit.
2.Regulator.
3.Reactor
4.HV Transformer.
5.AC/DC Resistive Potential Divider to measure 70KV AC /70KV DC.

INTEGRATED  CONTROL &  MEASUREMENT UNIT:

• Power Mains ON – OFF operation is done by means of Switch Disconnector with Fuse arrangement along with ‘MAINS ON’ lamp
• Control ON-OFF switch along with ‘CONTROL ON’ lamp indication & fuse
• AC/DC mode selector
• Isolation transformer for control operation, auxiliary supply to meters and power supply electronic PCBs.
• ‘HT ON’ push button along with ‘HT ON’ lamp indication along with ‘EMERGENCY OFF’ push
• INCREASE/DECREASE circuit to control motor operated Voltage   When  high  voltage  circuit  is  switched  ON  the  regulator  will  rotate  to  increase  the  output   voltage   when   INCREASE / DECREASE switch is kept in ‘INCREASE’ position and ‘INCREASE’ push is pressed ON or decrease the output voltage when the ‘INCREASE/ DECREASE’ switch is kept in ‘DECREASE’ position.

AC MEASURMENT:

• CT operated Digital AC Ammeter to measure the current at the input
• Digital AC Voltmeter scaled in KV connected to the low voltage arm of the HV Capacitive Potential Divider. Resolution: 1KV.
• CT operated Digital AC Ammeter with ‘PRESS TO READ mA’ push connected to the  earth potential end of the HV Transformer to measure the HT current. Resolution:
• CT operated Digital Ammeter for measurement of Reactor
• A ‘TIMER’ (0-999secs.) will be provided to measure the duration of applied HV. After completion of the test time the regulator will automatically decrease to zero position. ‘RESET’ feature of the  ‘TIMER’ will be

DC MEASURMENT:

• Output DC High Voltage is measured by means of properly designed HV Potential Divider and Digital voltmeter scaled in KV. Resolution 1KV.

• Digital milliammeter along with ‘PRESS TO READ mA’ push button for measure- ment of leakage current. Resolution 0.001mA for 1mA range & 0.01mA for 10mA

PROTECTION  & INTERLOCK:

• Zero start interlocking will be provided to ensure that the HV circuit cannot be energised unless the regulator is initially kept or brought back to zero
• Automatic tripping mechanism for protecting the HV transformer against over loading. The tripping mechanism can be adjusted at values as mentioned above. In addition to that, a protective device against overloading will be provided in the regulator output side and that will be set at maximum permissible loading in the regulator output
• HV Test Equipment & sample under test should be kept within an enclosure. Enclosure interlocking will be provided i.e. high voltage circuit cannot be energised unless the door of the enclosure is closed. However, this interlock can be by-passed by shorting corresponding
• In case the output voltage crosses the maximum rated value a lamp & a buzzer will indicate over voltage and the increase mode circuit will not function further, even if ‘PRESS TO INCREASE’ push is pressed.

The whole control circuitry will be housed within a sheet metal cabinet powder coated.

REGULATOR:

Continuously variable motorised voltage regulator of suitable capacity & control circuitry will  be  provided to increase & decrease the test voltage. Minimum & maximum position interlock will be provided so that limit switch will automatically disconnect Increase/Decrease  circuit  of  motor connection at maximum and minimum position respectively.

Over voltage protection i.e. in case the output voltage crosses the maximum rated value a buzzer will indicate over voltage and the increase mode circuit will not function further, even if  ‘PRESS  TO  INCREASE’ push is pressed.

REACTOR:

The device or component under testing being mainly capacitive a Reactor is required to avoid too low power  factor as well as for compensating the mains supply current.  The Reactor unit is a combination    of Fixed Reactor along with a Variable Reactor.

The range of Reactor setting can be done by brief manual link changeover arrangement. This Bank is so designed that the mains input current may be restricted within 40% of the rated input current.

The Variable Reactor will be motor controlled. Minimum & maximum position inter- lock for the Reactor will be provided so that limit switch will automatically discon-  nect ‘INCREASE/DECREASE’ circuit of motor connection at maximum and minimum position respectively.

Apart from the interlock facility overload tripping for the Reactor current will be provided.

HV TRANSFORMER:

HV Transformer used in the test set will be oil natural cooled type and of suitable capacity. One end of  the high voltage winding will get earth connection through a CT operated Ammeter & protective device while the other end will be connected to HT terminal.

The transformer will be designed to withstand frequent intermittent spark over or short circuit condi- tions under which such testing transformers are designed to operate.

AC/DC RESISTIVE HV POTENTIAL DIVIDER:

To be used with High Voltage source for High Voltage measurment Range     :           AC mode: 70kV rms

DC mode: 70kV peak

Overall Accuracy (Potential Divider + Readout unit) :+3% of the reading + 1digit.

HV RECTIFIER ADD-ON BLOCKS TO GET DCHV:

DC Output is available by half wave rectification of AC High voltage with HV diode bank housed within insulated cylinder and capacitor for smoothing the output. These elements will be with metallic fittings   at both ends to get proper electrical connection and form a rigid construction.

ACCESSORIES:

The set will be provided with input plug & socket, HV  Flexible  Connector, insulated  extension  rods,  Floor pedestal, connecting cups, connecting rod. DC HV output terminal and discharge rod  with grounding cable.

DOCUMENTS:

Operation Manual, Works Test Report, Warrantee Certificate will be supplied along with the set.