0
What is the normal insulation leakage current in three phase motor?
Wiki User
∙ 13y ago
zero
insulation leakage is known as a ground fault
AC, DC, single phase, 3 phase .... same answer
on a damp day or with water present it may be a bit higher than zero
there is no perfect insulation
if you have more than a milliamp you have problems
Wiki User
∙ 13y ago
Add your answer:
Earn +20 pts
What is the length of time that a motor can safely run on starting and full load current?
It depends on the insulation provided in winding, motor can safely run on full load current. and over that it may burn but depends on cooling system of the motor. Motor can burn if insulation fails, failure of insulation depends on only the temperature rise.
What is the minimum insulation of the motor for normal working condition?
5 mega ohms and above
How can the leakage flux be minimized in a dc motor?
An opposing magnetic field around the motor coil.
When does a motor draw current more than its rated current?
This is a good indication that the motor is being overloaded. If the motor load is belt driven, remove the belt and then check the motor amps. If it goes back to normal FLA then there is a problem with the driven load. If the motor amperage stays high check the motor bearings for the problem.
How do you test an electrical motor to see if is electrically faulty?
There is only two test you can do measure on the Ohm scale the resistance at the power connection if there is a reading then it means it's not open but that's not an indication that the motor is Ok, then measure on the MOhm scale between the body of the motor and any of the power connections if there is a reading then the motor have a internal short, the best is to open the motor and inspect it for black spots on the coils your nose is the best test smell it
How do you calculate earth leakage current for certain load example 5KW motor 660Vac?
There are many factors that determine what the leakage current will be. You could find out what the insulation winding resistance of the new motor should be and use the 660 volts and Ohm's law to calculate the current. If you measure this using a DC insulation tester however it probably will not yield an exact measurement since the test is not under normal operating conditions, but is a DC voltage test. To get the best measurement you really need to test the motor under operation and use a leakage clamp on the ground connection to see what the current really is since other factors come into play such as the insulation resistance, imbalance and frequency. An example of a tool would be the Fluke 1630 or Fluke 360.
What is the length of time that a motor can safely run on starting and full load current?
It depends on the insulation provided in winding, motor can safely run on full load current. and over that it may burn but depends on cooling system of the motor. Motor can burn if insulation fails, failure of insulation depends on only the temperature rise.
Why you use DOL starter in starting of motor?
because of starting current of induction motor is very high and it damages the insulation of motor
What is the minimum insulation of the motor for normal working condition?
5 mega ohms and above
Why do you have variation in leakage reactance of induction motor?
leakage reactance in induction motor depends on the reluctance of the path in which the leakage flux is establishing. with the increase in stator current the leakage flux also increases but it cannot maintain linear relationship because of saturation of the leakage flux path, even though current is increasing the flux will not increase and it'll be constant after saturation. this leakage flux links with the stator winding and induces emf which will be opposite to the supply voltage causes drop in applied voltage , the drop in the applied voltage is represented with the leakage reactance. as flux is responsible for the induction of emf , the increase in current does not increase flux after saturation and therefore emf also doesnot increase so the leakage reactance is not constant throughout the machine operation...
Dry run protection in pumps how it works?
A pump without water inlet is considered as motor without load. Hence the motor picksup more speed and draws more than the normal intended current there by the windings gets heated up before the insulation fails. Hence an arrangement to detect the over current (current more than the normal intended current) should be provided. The dry run protection utilises this principle of detecting the over current which inturn operates a relay or a control circuit to trip the motor circuit.
What will happen to a motor that is running that suddenly receives a heavy load?
The RPM of the motor will momentarily slow down, the current will go higher until the motor gets up to speed again. The motor will then go back to normal operation. If the load is in excess of the horse power rating of the motor, the motor will go into overload and the current will go higher that nameplate rating. If left in this condition the overload protection should trip the motor off line. If there is no protection on the motor, the life span of the motor is shortened likely from insulation failure.
How the normal speed of the dc motor can be set before varying the flux?
the normal speed of motor can be set by varing field current before using the turn
Causes of over temperature of induction motor?
the main reason is the amount of current flowing in the motor's winding is huge (over current) that why temperature begins to build up, continues using may end up to a burned motor. over voltage, defective bearing / bushing, shaft misalignment, defective insulation are some of the reason why motor experience over current.
How can the leakage flux be minimized in a dc motor?
An opposing magnetic field around the motor coil.
When does a motor draw current more than its rated current?
This is a good indication that the motor is being overloaded. If the motor load is belt driven, remove the belt and then check the motor amps. If it goes back to normal FLA then there is a problem with the driven load. If the motor amperage stays high check the motor bearings for the problem.
What is the effect of increasing the length of the air gap in an induction motor?
The magnetic flux that couples the rotor to the stator will weaken significantly reducing the motor's torque.
