Define insulation resistance.

Define insulation resistance.
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1 Answer

Answer :

The resistance to current leakage through the insulation.
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Related questions

What instrument is used for measuring the insulation resistance of cables?

Description : What instrument is used for measuring the insulation resistance of cables?

Last Answer : Megohmmeter (megger).

What stripping tool would NOT be used to strip glass braid insulation?

Description : What stripping tool would NOT be used to strip glass braid insulation?

Last Answer : Hot-blade stripper.

What materials are commonly used as cushions between cable insulation and metallic armor?

Description : What materials are commonly used as cushions between cable insulation and metallic armor?

Last Answer : Jute and Asphalt coverings.

State the reasons that the Navy is getting away from the use of asbestos insulation.

Description : State the reasons that the Navy is getting away from the use of asbestos insulation.

Last Answer : Breathing asbestos fibers can cause lung disease and/or cancer

If the insulation of a conductor was being measured in figure1-51 (A), would the reading indicate a good insulation?

Description : If the insulation of a conductor was being measured in figure1-51 (A), would the reading indicate a good insulation?

Last Answer : Yes.

What is a normal indication on a megger when checking insulation?

Description : What is a normal indication on a megger when checking insulation?

Last Answer : Infinity.

What is the procedure for using a megger to check the insulation of a conductor?

Description : What is the procedure for using a megger to check the insulation of a conductor?

Last Answer : Connect one lead to the insulation and one lead to the conductor. Turn the handcrank until it starts to slip. Note the reading

Define the temperature coefficient of resistance.

Description : Define the temperature coefficient of resistance.

Last Answer : The amount of increase in the resistance of a 1-ohm sample of the conductor per degree of temperature rise above 0º C

Define specific resistance.

Description : Define specific resistance.

Last Answer : The resistance of a unit volume of a substance.

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

An open in the armature of a DC motor is suspected, but is not found by visual inspection of the commutator. The next step in troubleshooting this problem is to ________________. A. conduct a bar to bar test of the armature B. visually inspect the armature windings C. conduct an insulation resistance test of the armature D. test the commutator for a ground

Description : An open in the armature of a DC motor is suspected, but is not found by visual inspection of the commutator. The next step in troubleshooting this problem is to ________________. A. conduct a ... windings C. conduct an insulation resistance test of the armature D. test the commutator for a ground

Last Answer : Answer: A

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

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 insulation failure produces a low resistance current path between two conductors, the resulting condition is known as ____________. A. an open B. a short circuit C. a ground D. a surge

Description : When insulation failure produces a low resistance current path between two conductors, the resulting condition is known as ____________. A. an open B. a short circuit C. a ground D. a surge

Last Answer : Answer: B

When working on electrical circuits containing large capacitors, in addition to deenergizing the circuit, which of the listed precautions should also be taken? A. Keep all radio equipment away. B. Measure capacitor insulation resistance. C. Ground the capacitor terminals. D. Check capacitor circuit polarity.

Description : When working on electrical circuits containing large capacitors, in addition to deenergizing the circuit, which of the listed precautions should also be taken? A. Keep all radio equipment ... capacitor insulation resistance. C. Ground the capacitor terminals. D. Check capacitor circuit polarity.

Last Answer : Answer: C

A galvanometer is an instrument used to measure ___________. A. thickness of galvanized metal B. resistance of electrical wiring insulation C. very small amounts of current or voltage D. quantity of galvans in an electric circuit

Description : A galvanometer is an instrument used to measure ___________. A. thickness of galvanized metal B. resistance of electrical wiring insulation C. very small amounts of current or voltage D. quantity of galvans in an electric circuit

Last Answer : Answer: C

Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. lowers the insulation value and is a common cause of fault grounds in idle machines C. will enhance insulation resistance only if it is fresh water and contains no salt D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Description : Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. ... D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Last Answer : Answer: B

Which of the instruments listed is used to check insulation resistance? A. Magneto B. Megohmmeter C. Dynamometer D. Rheostat

Description : Which of the instruments listed is used to check insulation resistance? A. Magneto B. Megohmmeter C. Dynamometer D. Rheostat

Last Answer : Answer: B

When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter pointer _____________. A. fluctuating around a constant resistance reading B. dipping towards 'zero', then rising slowly C. kicking slightly downscale as voltage is applied D. continually rising as the test voltage is applied

Description : When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter pointer _____________. A. fluctuating around a ... slightly downscale as voltage is applied D. continually rising as the test voltage is applied

Last Answer : Answer: C

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

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

The existing resistance of a conductor is dependent upon its length, cross-sectional area, _____________. A. temperature and insulation B. material and insulation C. resistive coefficient and material D. material and temperature

Description : The existing resistance of a conductor is dependent upon its length, cross-sectional area, _____________. A. temperature and insulation B. material and insulation C. resistive coefficient and material D. material and temperature

Last Answer : Answer: D

When the current flow through a copper wire increases, its _____________. A. resistance will decrease B. insulation will burn C. temperature will increase D. conductivity will increase

Description : When the current flow through a copper wire increases, its _____________. A. resistance will decrease B. insulation will burn C. temperature will increase D. conductivity will increase

Last Answer : Answer: C

During its operation, loud buzzing and resultant welding of contacts of a magnetic relay may be caused by __________. A. overheating of the contactor coil B. low voltage on the operating coil C. low insulation resistance to ground D. lubrication of the contact bearing points

Description : During its operation, loud buzzing and resultant welding of contacts of a magnetic relay may be caused by __________. A. overheating of the contactor coil B. low voltage on the operating coil C. low insulation resistance to ground D. lubrication of the contact bearing points

Last Answer : Answer: B

Which of the listed statements is correct when using an analog multimeter as an ohmmeter? A. The pointer should be adjusted to zero each time a new resistance range is selected. B. The pointer will move to infinity when the meter is not in use. C. Ohmmeters are not sufficiently sized to measure conductor insulation resistance. D. All of the above.

Description : Which of the listed statements is correct when using an analog multimeter as an ohmmeter? A. The pointer should be adjusted to zero each time a new resistance range is selected. B. The ... C. Ohmmeters are not sufficiently sized to measure conductor insulation resistance. D. All of the above.

Last Answer : Answer: D

When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter's pointer _____________. A. dipping toward zero then raising slowly B. continually rising as test voltage is applied C. kicking slightly down scale as voltage is applied D. fluctuating around a constant resistance reading

Description : When a megohmmeter is being used to test insulation resistance, current leakage along the surface of the insulation is indicated by the megohmmeter's pointer _____________. A. dipping toward ... kicking slightly down scale as voltage is applied D. fluctuating around a constant resistance reading

Last Answer : Answer: C

To carry out an insulation resistance test, one terminal of the megohmmeter should be connected to the winding, with the other terminal being connected to the ____________________. A. power supply B. variable resistor C. frame of the machine D. armature

Description : To carry out an insulation resistance test, one terminal of the megohmmeter should be connected to the winding, with the other terminal being connected to the ____________________. A. power supply B. variable resistor C. frame of the machine D. armature

Last Answer : Answer: C

You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, becoming fairly steady as the leakage current stabilizes B. remain constant as the temperature of the windings increases C. continue to drop as the potential is maintained, becoming fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation

Description : You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, ... fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation

Last Answer : Answer: A

An insulation resistance reading is taken at 20°C and found to be 10 megohms. What would you expect the resistance reading to be at 40°C? A. 2.5 megohms B. 10 megohms C. 15 megohms D. 20 megohms

Description : An insulation resistance reading is taken at 20°C and found to be 10 megohms. What would you expect the resistance reading to be at 40°C? A. 2.5 megohms B. 10 megohms C. 15 megohms D. 20 megohms

Last Answer : Answer: A

When using a megohmmeter to test insulation, good insulation will be indicated by _____________. A. slight kicks of the needle down scale B. a downward dip followed by a gradual climb to the true resistance value C. a gradual rise in the pointer reading at the outset D. the initial dip of the pointer

Description : When using a megohmmeter to test insulation, good insulation will be indicated by _____________. A. slight kicks of the needle down scale B. a downward dip followed by a gradual climb to the true resistance ... C. a gradual rise in the pointer reading at the outset D. the initial dip of the pointer

Last Answer : Answer: B

When a megohmmeter is used to test insulation, the gradual rise of the pointer reading as a result of continued cranking, is caused by _____________. A. good conductor resistance B. the leakage of current along the surface of dirty insulation C. the inductive reactance of the windings D. the dielectric-absorption effect of the insulation

Description : When a megohmmeter is used to test insulation, the gradual rise of the pointer reading as a result of continued cranking, is caused by _____________. A. good conductor resistance B. the ... insulation C. the inductive reactance of the windings D. the dielectric-absorption effect of the insulation

Last Answer : Answer: D

Copper is often used as an electrical conductor because it _______________. A. has high resistance at low temperatures B. has a highly polished surface C. is able to pass current with little opposition D. holds insulation together well

Description : Copper is often used as an electrical conductor because it _______________. A. has high resistance at low temperatures B. has a highly polished surface C. is able to pass current with little opposition D. holds insulation together well

Last Answer : Answer: C

On tank vessels with an electrically-driven capstan, the motor should be meggered periodically to test _____________. A. insulation resistance B. eddy currents C. capacitance D. armature reactance

Description : On tank vessels with an electrically-driven capstan, the motor should be meggered periodically to test _____________. A. insulation resistance B. eddy currents C. capacitance D. armature reactance

Last Answer : Answer: A

The insulation resistance of electric equipment and machinery should be tested for the lowest normal insulation values _____________. A. immediately after shutting down the machine B. every time the brush rigging is adjusted C. immediately after starting up the machine D. every 30 days whether the machine is in use or not

Description : The insulation resistance of electric equipment and machinery should be tested for the lowest normal insulation values _____________. A. immediately after shutting down the machine B. every time the brush rigging is ... starting up the machine D. every 30 days whether the machine is in use or not

Last Answer : Answer: A

An insulation resistance test is performed on a particular piece of electric equipment. In addition to the resistance reading, what information listed below should be entered in the electrical log? A. The maximum allowable operating temperature of the machine. B. The temperature of the machine at the time the resistance reading was taken. C. The normal temperature rise of the machine. D. The complete nameplate data from the resistance test instrument used to obtain the reading.

Description : An insulation resistance test is performed on a particular piece of electric equipment. In addition to the resistance reading, what information listed below should be entered in the electrical log? A. ... D. The complete nameplate data from the resistance test instrument used to obtain the reading.

Last Answer : Answer: B

What should be the value of insulation resistance of induction motor?

Description : What should be the value of insulation resistance of induction motor? 

Last Answer : In Rm = kV + 1 M OHMS. Insulation resistance of any electrical machine (motor or generator) should be above 0.5-M ohms in all cases. 

What are the points contributes in insulation resistance of the motor?

Description : What are the points contributes in insulation resistance of the motor?

Last Answer : If the measured insulation resistance of the motor is less than 1 MΩ / kV with a minimum of 1MΩ, when the machine is cold it is to be dried out before full voltage is applied to the terminals of ... voltage. f. Residual charge in the winding. g. Ageing of the insulation. h. Mechanical stresses.  

The insulation resistance of a DC motor is observed to be 15 MΩ at a temp. of 70°C. what is its value corrected to 40°C. the correction factor for 70°C is 8.0.

Description : The insulation resistance of a DC motor is observed to be 15 MΩ at a temp. of 70°C. what is its value corrected to 40°C. the correction factor for 70°C is 8.0. 

Last Answer : Observed resistance at 70°C – 15 MΩ. Temperature correction factor – 8. Rm = kt * Rt           kt – correction factor. Rm = 8 * 15          Rt – resistance measured at +°C. Rm = 120 MΩ.       Rm – corrected value to 40°C The IR of DC motor corrected to 40°C is 120 MΩ. 

Insulation resistance of high voltage circuit breakers is more than (a) 1 mega ohms (b) 10 mega ohms (c) 100 mega ohms (d) 500 mega ohms

Description : Insulation resistance of high voltage circuit breakers is more than (a) 1 mega ohms (b) 10 mega ohms (c) 100 mega ohms (d) 500 mega ohms

Last Answer : (c) 100 mega ohms

Resistance measuring instrument particularly used in determining the insulation resistance

Description : Resistance measuring instrument particularly used in determining the insulation resistance

Last Answer : Megger/Megaohmmeter

Insulation resistance is measured by which meter?

Description : Insulation resistance is measured by which meter?

Last Answer : megger

Indicate the three types oftransmissionline energylosses. a. I2R, R , and temperature b. Radiation, I2R, and dielectric heating c. Dielectric separation, insulation breakdown, and radiation d. Conductor heating, dielectric heating, and radiation resistance.

Description : Indicate the three types oftransmissionline energylosses. a. I2R, R , and temperature b. Radiation, I2R, and dielectric heating c. Dielectric separation, insulation breakdown, and radiation d. Conductor heating, dielectric heating, and radiation resistance.

Last Answer : b. Radiation, I2R, and dielectric heating

49 The open circuit test is carried out in a transformer to find the A. Cu loss B. Core loss C. Total loss D. Insulation resistance

Description : 49 The open circuit test is carried out in a transformer to find the A. Cu loss B. Core loss C. Total loss D. Insulation resistance

Last Answer : B. Core loss

State the methods used to measure insulation resistance and explain Dielectric Absorption method.

Description : State the methods used to measure insulation resistance and explain Dielectric Absorption method.

Last Answer : There are three types of tests for measuring insulation resistance:  1. Spot test reading or Short Time test  2.Time-resistance test or Dielectric absorption test or Testing methods based on the PI & DAR  3. ... and if value of PI is less than 2 and value of DAR is less than 1.25

Name the method used to measure following resistances:- (i) Low resistance (ii) Medium resistance (iii) Insulation resistance (iv) Earth resistance.

Description : Name the method used to measure following resistances:- (i) Low resistance (ii) Medium resistance (iii) Insulation resistance (iv) Earth resistance.

Last Answer : Following are the methods used to measure resistances:-  (i) Low resistance: 1.Voltmeter-Ammeter Method 2. Kelvin's Double bridge Method  (ii) Medium resistance: 1.Voltmeter-Ammeter Method 2. ... of Charge Method  (iv) Earth resistance : 1. Fall of Potential Method 2. Earth tester

If the insulation resistance of a cable of length 10 km is 1 mega ohm, its insulation resistance

Description : If the insulation resistance of a cable of length 10 km is 1 mega ohm, its insulation resistance for 50 km length will be

Last Answer : If the insulation resistance of a cable of length 10 km is 1 mega ohm, its insulation resistance for 50 km length will be 0.2 mega ohm