Different between megger and contact resistance meter?

Different between megger and contact resistance meter?
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1 Answer

Answer :

 Megger used to measure cable resistance, conductor continuity, phase identification where as contact resistance meter used to
measure low resistance like relays, contactors.
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Related questions

Different between megger and contact resistance meter?

Description : Different between megger and contact resistance meter?

Last Answer : Answers: Megger used to measure cable resistance, conductor continuity, phase identification where as contact resistance meter used to measure low resistance like relays ,contactors.

What is the difference between megger test equipment and contact resistance meter test instruments?

Description : What is the difference between megger test equipment and contact resistance meter test instruments?

Last Answer : Megger test equipment used to measure cable electric resistance, conductor continuity, phase identification. Contact resistance meter test instruments used to measure low resistance like relays, contactors.

A useful instrument for checking A.C. motor performance by measuring possible unbalanced currents is the _____________. A. hand or battery-operated megger B. vibrating-reed frequency meter C. hook-on voltmeter-ammeter D. D'Arsonval iron-vane probe

Description : A useful instrument for checking A.C. motor performance by measuring possible unbalanced currents is the _____________. A. hand or battery-operated megger B. vibrating-reed frequency meter C. hook-on voltmeter-ammeter D. D'Arsonval iron-vane probe

Last Answer : Answer: C

Routine maintenance of dry-type transformers should include ______________. A. preventing the entrance of water from broken pipe lines steam lines B. keeping protective surfaces and insulating bushings free of dirt and conductive debris C. periodic testing of insulation resistance with a megger D. all of the above

Description : Routine maintenance of dry-type transformers should include ______________. A. preventing the entrance of water from broken pipe lines steam lines B. keeping protective surfaces and insulating bushings free of ... debris C. periodic testing of insulation resistance with a megger D. all of the above

Last Answer : Answer: D

When troubleshooting motor controllers, a shorted relay or contactor coil is often indicated by _______________. A. a resistance reading of 'infinity' on an ohmmeter B. charred insulation and/or a blown control fuse C. a reading of 'zero' on a megger from one of the coil's leads to ground D. a higher-than-normal voltage reading across the winding

Description : When troubleshooting motor controllers, a shorted relay or contactor coil is often indicated by _______________. A. a resistance reading of 'infinity' on an ohmmeter B. charred insulation and/or a blown ... of the coil's leads to ground D. a higher-than-normal voltage reading across the winding

Last Answer : Answer: B

Why is a Megger used for insulation test and not a multi meter?

Description : Why is a Megger used for insulation test and not a multi meter?

Last Answer : With a megger,a voltage of not less than 500 volts DC is used for testing the insulation resistance of windings. With a multi-meter, the voltage used is not more than 3-volts DC. Megger uses high impedance testing and is therefore more accurate than a multi-meter

The reading at 'M' on the megger scale illustrated, is ____. EL-0044 A. 7.1 meg ohms B. 71 meg ohms C. .71 meg ohms D. 200,000,000 ohms

Description : The reading at 'M' on the megger scale illustrated, is ____. EL-0044 A. 7.1 meg ohms B. 71 meg ohms C. .71 meg ohms D. 200,000,000 ohms

Last Answer : Answer: A

When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across the top of the first line fuse and the bottom of the third line fuse C. apply the voltage tester across the bottoms of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester

Description : When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across ... of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester

Last Answer : Answer: D

The reading at 'M' on the megger scale shown in the illustration, is __________. EL-0044 A. 7.1 meg ohms B. .71 meg ohms C. 71 meg ohms D. 200,000,000 ohms

Description : The reading at 'M' on the megger scale shown in the illustration, is __________. EL-0044 A. 7.1 meg ohms B. .71 meg ohms C. 71 meg ohms D. 200,000,000 ohms

Last Answer : Answer: A

Which of the conditions listed will indicate the need to clean the insulation on the windings of an electric motor? A. Higher than normal operating temperature. B. Excessive vibration at normal speed. C. Sparking at the brushes. D. High megger readings.

Description : Which of the conditions listed will indicate the need to clean the insulation on the windings of an electric motor? A. Higher than normal operating temperature. B. Excessive vibration at normal speed. C. Sparking at the brushes. D. High megger readings.

Last Answer : Answer: A

The reading at 'Z' on the megger scale shown in the illustration is ____________. EL-0044 A. 30,000 ohms B. 300,000 ohms C. 3,000,000 ohms D. 30,000,000 ohms

Description : The reading at 'Z' on the megger scale shown in the illustration is ____________. EL-0044 A. 30,000 ohms B. 300,000 ohms C. 3,000,000 ohms D. 30,000,000 ohms

Last Answer : Answer: C

The reading at 'K' on the megger scale shown in the illustration, is ______________. EL-0044 A. 400 ohms B. 4,000 ohms C. 40,000 ohms D. 400,000 ohms

Description : The reading at 'K' on the megger scale shown in the illustration, is ______________. EL-0044 A. 400 ohms B. 4,000 ohms C. 40,000 ohms D. 400,000 ohms

Last Answer : Answer: D

The reading at 'C' on the megger scale illustrated, is ________. EL-0044 A. 200,000 ohms B. 2,000,000 ohms C. 20,000,000 ohms D. 200,000,000 ohms

Description : The reading at 'C' on the megger scale illustrated, is ________. EL-0044 A. 200,000 ohms B. 2,000,000 ohms C. 20,000,000 ohms D. 200,000,000 ohms

Last Answer : Answer: C

The reading at 'V' on the megger scale shown in the illustration, is __________. EL-0044 A. 40 meg ohms B. 0.40 meg ohms C. 4.0 kilo ohms D. 40,000 ohms

Description : The reading at 'V' on the megger scale shown in the illustration, is __________. EL-0044 A. 40 meg ohms B. 0.40 meg ohms C. 4.0 kilo ohms D. 40,000 ohms

Last Answer : Answer: D

The reading at 'P' on the megger scale shown in the illustration, is __________. EL-0044 A. 15 meg ohms B. 1.5 meg ohms C. 1.5 kilo ohms D. 150,000 ohms

Description : The reading at 'P' on the megger scale shown in the illustration, is __________. EL-0044 A. 15 meg ohms B. 1.5 meg ohms C. 1.5 kilo ohms D. 150,000 ohms

Last Answer : Answer: B

Which of the listed conditions could indicate the need for cleaning electrical insulation? A. Low ambient temperature B. Low operating temperature C. High dielectric strength D. Low megger readings

Description : Which of the listed conditions could indicate the need for cleaning electrical insulation? A. Low ambient temperature B. Low operating temperature C. High dielectric strength D. Low megger readings

Last Answer : Answer: D

Discharge switches are often located on hand-driven meggers. The purpose of these switches is to discharge capacitive charges stored in the _____________. A. megger hand generator B. megger movement coils C. tested equipment while conducting test D. tested equipment after testing

Description : Discharge switches are often located on hand-driven meggers. The purpose of these switches is to discharge capacitive charges stored in the _____________. A. megger hand generator B. megger movement coils C. tested equipment while conducting test D. tested equipment after testing

Last Answer : Answer: D

The need for insulation cleaning may be determined by _____. A. visual inspection for dirt accumulation B. high megger readings C. low operating temperature D. the time period since the last cleaning

Description : The need for insulation cleaning may be determined by _____. A. visual inspection for dirt accumulation B. high megger readings C. low operating temperature D. the time period since the last cleaning

Last Answer : Answer: A

If the pointer on a megger fails to return to 'zero' when not being used, the _____________. A. megger is out of calibration B. megger is operating normally C. hairsprings are burned out D. pointer probably stuck in that position

Description : If the pointer on a megger fails to return to 'zero' when not being used, the _____________. A. megger is out of calibration B. megger is operating normally C. hairsprings are burned out D. pointer probably stuck in that position

Last Answer : Answer: B

Electrical machinery insulation will break down more rapidly due to _________________. A. low loading of motors and generators B. frequent megger testing C. high temperatures and vibration D. high operating frequencies

Description : Electrical machinery insulation will break down more rapidly due to _________________. A. low loading of motors and generators B. frequent megger testing C. high temperatures and vibration D. high operating frequencies

Last Answer : Answer: C

Routine maintenance of a ship's service alternator should include ______________. A. changing the pedestal bearing insulation yearly B. megger testing of all rectifying diodes C. lubricating excitation slip rings D. periodic cleaning of the air filters or screens

Description : Routine maintenance of a ship's service alternator should include ______________. A. changing the pedestal bearing insulation yearly B. megger testing of all rectifying diodes C. lubricating excitation slip rings D. periodic cleaning of the air filters or screens

Last Answer : Answer: D

A suspected 'open' in a motor field can be tested by using a/an ____________. A. potentiometer B. megger C. wattmeter D. ammeter

Description : A suspected 'open' in a motor field can be tested by using a/an ____________. A. potentiometer B. megger C. wattmeter D. ammeter

Last Answer : Answer: B

To determine if a stator coil is grounded, you should use a/an _____________. A. ammeter B. ground detection lamp C. magneto D. megger

Description : To determine if a stator coil is grounded, you should use a/an _____________. A. ammeter B. ground detection lamp C. magneto D. megger

Last Answer : Answer: D

If the pointer fails to return to zero when a megger is disconnected, the _____________. A. pointer is stuck B. hair springs are burned out C. megger is out of calibration D. megger is operating normally

Description : If the pointer fails to return to zero when a megger is disconnected, the _____________. A. pointer is stuck B. hair springs are burned out C. megger is out of calibration D. megger is operating normally

Last Answer : Answer: D

The electrician reports to you that he has obtained low (but above 1 megohm) megger readings on the windings of a deck winch motor. Upon checking the records of that motor, you find the readings have consistently been at that level for the last six yea A. motor be replaced B. windings be dried C. windings be cleaned D. readings are acceptable

Description : The electrician reports to you that he has obtained low (but above 1 megohm) megger readings on the windings of a deck winch motor. Upon checking the records of that motor, you find the readings have ... yea A. motor be replaced B. windings be dried C. windings be cleaned D. readings are acceptable

Last Answer : Answer: D

A generator has been exposed to water and is being checked for its safe operation. Therefore, it is necessary to _______________. A. check for shorted coils with a growler B. take moisture readings with a hydrometer C. test insulation values with a megger D. ground the commutator, or slip rings and run it at half load for 12 hours

Description : A generator has been exposed to water and is being checked for its safe operation. Therefore, it is necessary to _______________. A. check for shorted coils with a growler B. take moisture readings with a ... a megger D. ground the commutator, or slip rings and run it at half load for 12 hours

Last Answer : Answer: C

As shown in the illustration, what maintenance would be required of the circuit components? EL-0058 A. Change out both 'C' units monthly. B. Clean the glass surrounding 'E1' & 'E2' as needed. C. File the points at the upper end of 'G' every six months. D. Take megger readings on 'E1' & 'E2' windings quarterly.

Description : As shown in the illustration, what maintenance would be required of the circuit components? EL-0058 A. Change out both 'C' units monthly. B. Clean the glass surrounding 'E1' & 'E2' as needed. C. File ... upper end of 'G' every six months. D. Take megger readings on 'E1' & 'E2' windings quarterly.

Last Answer : Answer: B

As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to _____________. A. draw a one line diagram of the circuitry B. test all fuses and measure the line voltage C. take megger readings D. insulate the apparatus from ground

Description : As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to _____________. A. draw a one line diagram of the circuitry B. test all fuses and measure the line voltage C. take megger readings D. insulate the apparatus from ground

Last Answer : Answer: B

What is Megger?

Description : What is Megger?

Last Answer : The megohmmeter, commonly called a megger for short, is used to measure very high resistance values. It is primarily used to test the insulation of conductors. To measure high resistance values, a high voltage is applied, either by the use of a handcranked generator or electronic power supply. 

Why megger value of 1 minute is less than 10-minute value?

Description : Why megger value of 1 minute is less than 10-minute value?

Last Answer : After 10 minutes the high voltage applied make the molecules such a way that stabilised in a good insulation. If insulation is weak it leads to more leakage current due to high potential. 

Why guard connection is given for megger?

Description : Why guard connection is given for megger?

Last Answer : For true measurement of IR value of HV to earth of a transformer, connect line to HV, earth to transformer tank and guard to LV. Therefore leakage current from HV to LV is not included.  

A megger is to measure insulation resistance of a cable. The cable should be connected to

Description : A megger is to measure insulation resistance of a cable. The cable should be connected to   (a) Battery (b) DC supply (c) AC supply (d) No supply  

Last Answer : majorly in DC as well as AC......but ans is Battery

To measure insulation resistance of equipments of voltage rating upto 440 V the megger generator must generate...

Description : To measure insulation resistance of equipments of voltage rating upto 440 V the megger generator must generate   (a) 220 V (b) 440 V (c) 500 V (d) None of these 

Last Answer : 500 V

A current carrying conductor making an electrical contact with a wiring metal conduit is indicated by a _____________. A. low switchboard wattmeter reading B. reading of 1.0 on the power factor meter C. high switchboard voltmeter reading D. totally darkened switchboard ground-detecting light

Description : A current carrying conductor making an electrical contact with a wiring metal conduit is indicated by a _____________. A. low switchboard wattmeter reading B. reading of 1.0 on the power factor meter C. high switchboard voltmeter reading D. totally darkened switchboard ground-detecting light

Last Answer : Answer: D

In preparing to take insulation resistance readings on a main generator, the windings should be grounded for about 15 minutes prior to the test to _____________. A. allow accurate zeroing of the meter B. help the windings to cool to ambient temperature C. release any residual capacitive charge from the windings D. help the windings to cool to the same temperature as the ground test connection

Description : In preparing to take insulation resistance readings on a main generator, the windings should be grounded for about 15 minutes prior to the test to _____________. A. allow accurate zeroing of the meter ... the windings D. help the windings to cool to the same temperature as the ground test connection

Last Answer : Answer: C

When a megohmmeter is being used on a alternating current machine, the meter pointer will dip toward 'zero' and then gradually rise to the true resistance value if the motor insulation is _____________. A. grounded B. good C. shorted D. dirty

Description : When a megohmmeter is being used on a alternating current machine, the meter pointer will dip toward 'zero' and then gradually rise to the true resistance value if the motor insulation is _____________. A. grounded B. good C. shorted D. dirty

Last Answer : Answer: B

If reading AC current with the illustrated device and unsure of the range as a precaution , the first step should be to _________. EL-0047 A. secure power and test for voltage B. disconnect the lead to be tested and connect the meter in series C. connect the meter to measure resistance and use Ohm's law to calculate current D. unable to safely measure current with the device

Description : If reading AC current with the illustrated device and unsure of the range as a precaution , the first step should be to _________. EL-0047 A. secure power and test for voltage B. disconnect the ... resistance and use Ohm's law to calculate current D. unable to safely measure current with the device

Last Answer : Answer: A

The illustrated circuit is a wheatstone bridge. If the meter 'G' reads 0 with the switch closed then ________. EL-0024 A. the current through R1 - R2 is equal to the current through R3 - Rx B. the voltage across b - d is equal to the voltage of E C. the resistance of Rx is equal to the resistance of R2 D. all the above are true

Description : The illustrated circuit is a wheatstone bridge. If the meter 'G' reads 0 with the switch closed then ________. EL-0024 A. the current through R1 - R2 is equal to the current through R3 - Rx B. the voltage ... of E C. the resistance of Rx is equal to the resistance of R2 D. all the above are true

Last Answer : Answer: A

An internal resistance is placed in series with the meter movement of which of the following instruments? A. AC ammeter B. DC ammeter C. DC voltmeter D. Frequency meter

Description : An internal resistance is placed in series with the meter movement of which of the following instruments? A. AC ammeter B. DC ammeter C. DC voltmeter D. Frequency meter

Last Answer : Answer: C

When a resistor is used as a shunt and is connected in parallel with a meter movement coil, it will provide _____________. A. a measurement of circuit resistance B. an increased accuracy of approximately 1.5 percent C. an extended meter range D. none of the above

Description : When a resistor is used as a shunt and is connected in parallel with a meter movement coil, it will provide _____________. A. a measurement of circuit resistance B. an increased accuracy of approximately 1.5 percent C. an extended meter range D. none of the above

Last Answer : Answer: C

A capacitor is to be tested with a megohmmeter. If the meter is connected to a shorted capacitor, the meter pointer should _____________. A. immediately swing to the maximum resistance value B. deflect to zero and remain at that position C. swing to a high reading and gradually decrease D. swing to zero then gradually increase with slight pointer movements down scale

Description : A capacitor is to be tested with a megohmmeter. If the meter is connected to a shorted capacitor, the meter pointer should _____________. A. immediately swing to the maximum resistance value ... and gradually decrease D. swing to zero then gradually increase with slight pointer movements down scale

Last Answer : Answer: B

The basic meter movement responds to the flow of current through its coil. Therefore, this meter movement may be used as a/an _____________. A. voltmeter by placing a resistance in parallel with the coil B. ohmmeter by placing another meter movement in parallel with the coil C. wattmeter by placing a battery in parallel with the coil D. ammeter by placing a low resistance in parallel with the coil

Description : The basic meter movement responds to the flow of current through its coil. Therefore, this meter movement may be used as a/an _____________. A. voltmeter by placing a resistance in parallel with the ... in parallel with the coil D. ammeter by placing a low resistance in parallel with the coil

Last Answer : Answer: D

Before using a volt-ohmmeter to measure resistance readings, you should _____________. A. replace all batteries B. test the insulation resistance of the leads C. make sure the test leads do not touch D. hold the leads together and 'zero' the meter

Description : Before using a volt-ohmmeter to measure resistance readings, you should _____________. A. replace all batteries B. test the insulation resistance of the leads C. make sure the test leads do not touch D. hold the leads together and 'zero' the meter

Last Answer : Answer: D

Prior to taking a resistance reading with a volt-ohm-milliammeter, the 'zero' setting must be adjusted. After clipping the two leads together, you find the adjustment knob will not return the pointer to 'zero'. This is most likely an indication of ______ A. an improper resistance range setting B. weak batteries C. a faulty zero ohms knob D. a faulty meter movement

Description : Prior to taking a resistance reading with a volt-ohm-milliammeter, the 'zero' setting must be adjusted. After clipping the two leads together, you find the adjustment knob will not return the pointer ... range setting B. weak batteries C. a faulty zero ohms knob D. a faulty meter movement

Last Answer : Answer: B

In order to increase its range of measurement, a resistance would be placed in series with which of the following instruments? A. DC voltmeter B. DC ammeter C. frequency meter D. power factor meter

Description : In order to increase its range of measurement, a resistance would be placed in series with which of the following instruments? A. DC voltmeter B. DC ammeter C. frequency meter D. power factor meter

Last Answer : Answer: A

To test fuses in an energized circuit, you should use a ____________. A. low voltage light bulb B. megohmmeter C. voltmeter D. resistance meter

Description : To test fuses in an energized circuit, you should use a ____________. A. low voltage light bulb B. megohmmeter C. voltmeter D. resistance meter

Last Answer : Answer: C