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Depends firstly on the type of motor and secondly what your testing for.
If you are the manufacturer, you test according to the IEC/AS Codes for electromechanical machines.
Considering just one type of 3 phase motor, the Squirrel Cage: if you are testing it electrically, then first of all you have to check the insulation resistance of each phase to earth with an appropriately sized megger (insulation tester). Then you measure the stator's winding resistance between each phase. (You don't check the phase-to-phase on the rotor as it's basically a dead short for Squirrel Cage motors.)
If you are load-testing, depending on the codes you are following, you start it up and run it for around 8 hours. During this period you take temperature measurements on the windings and the bearings and vibration measurements of the bearings. For the stator windings, you just measure the temperature of the stator housing unless the motor is big enough to have its own set of built-in RTDs. (Remote Temperature Detectors.)
Wiki User
∙ 12y ago
Wiki User
∙ 12y agoYou use a megger. This allows you to check what the condition of the insulation of the motor windings are. It is an insulation test to see is the insulation has been injured in any way to cause a short circuit when normal power is applied to it. On my megger there are 3 ranges 300V, 750V, and 1000 volts. Applying the proper voltage is essential to not damaging the device you are testing. Working voltages up to 240 volts should use the 300 range. Working voltages up to 600 volts use the 750 volt range and working voltages above 600 use the 1000 volt range. As you can see if you used the 1000 volt range on a device that had a working voltage of say 24 volts you could damage the insulation just by testing it. Connect one lead of the megger to the frame of the motor and the other lead to the end of the coil winding. If the motor has a start and run winding both coils must be checked.
Wiki User
∙ 8y agoIf by using the word "check" it is meant to establish the condition of the motor in an operative state, then there are a couple of things that can be done. The very first thing is to measure the amperage that the motor is drawing and compare that value to what the manufacturer recommends on the motor's nameplate. The second and important thing to do is establish the condition of the motors windings to ground. This is done with a megger. Continuous readings over the life time of the motor will show a continuous degrading of the insulation capacity of the motor' internal windings. When the readings get low enough, at some point in time the decision has to be made as to whether it is time to replace the motor before the windings short circuit and there is a total motor failure. In large industrial installations this type of preventative maintenance prevents production line shut downs.
Wiki User
∙ 13y agoGo to your local marina, and connect to the 3 phase shore power there. If the motor spins at proper speed, you should be good.
Wiki User
∙ 11y agohow to test starting and running windings
Wiki User
∙ 11y agowith a muiltermeter.
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Can a starter used for 5 hp 3 phase motor be used for 7.5 hp 3 phase motor?
No.
What you basically want is will each phase take 26 Amps current for 15HP 3 phase 415VAC motor?
Yes. In a 3-phase motor, all 3 phases have the same current.
How much more efficient is a 2 hp 240 v 3 phase motor compared to a 120 v single phase 2 hp motor?
I would guess it would use a third less than a single phase motor. The voltage differences don't save but 3 phase does. A 3 phase motor also starts easier.
Which phase is the reverse phase?
Connecting Phase A, B and C to the motor leads will make a 3 phase motor run in one direction while interchanging any two will make the motor rotate in the opposite direction.
Why would you use 2 point starters instead of 3 point starters for a motor?
traditionally, 3 contact starters are for a three phase motor and two contact starters are for a single phase motor.
When connecting a external generator 3 phase to an existing 3 phase electrical network how do you know that the 2 systems are in phase?
use a rotor phaser or simply connect a 3 phase motor and check dirrection
Why cannot test phase to phase on 3 phase motor?
Motor voltages and amperages can both be tested. The best way to test the continuity of a motor is with a megger. This will check that the motor windings are intact and if there is any voltage leakage to ground or voltage leakage to one of the other two windings in the motor. To check amperages on the motor it will have to be energized. Leave a message in discussion page as to what you are trying to do. <<>> Because there is no such thing as 'phase to phase'! However, there is such a thing as 'line to line', and this can be tested!
Is 3 phase motor run on 1 phase supply?
No. That would be a single phase motor.
How do you turn a 3 phase motor in to a generator?
We can convert a 3 phase ac motor into generator by changing phase sequence of the ac input cable of that motor
Can you replace a 480-240V 3-phase motor with a single phase motor as a temporary replacement or will it burn it out?
Yes, you can, and it won't burn out IF>>> the horsepower rating is the SAME. Pay attention to wiring and motor rotation. Also check the voltage: the motor voltage must be the same as the voltage between two hots of your 3 phase system. You will only use two hots as this is a single phase motor.
How do you check single phase motor winding?
Single phase motor winding is often checked just by listening to the noise that the motor is making. An experienced person can tell if the motor is working at single phase or double phase.
How can you determine if a electric motor is 1 phase or 3 phase if there is no name plate?
Check the motor's terminal box. If there are three service input cables - such as red, yellow and blue - plus an earth wire, then it is a three phase motor. If there are only two wires plus an earth wire, then it is single phase.
Can a starter used for 5 hp 3 phase motor be used for 7.5 hp 3 phase motor?
No.
Can I test wires from a 3 phase motor to see if its configured in low or high voltage?
Using a multimeter, check the continuity of motor winding from phase to phase ( U to V, V to W , W to U ). Each phase to phase must have a continuity if winding is OK. If any particular phase fails the continuity test, your motor is probably burnt.
Is a 3 phase motor a Synchronous motor?
A synchronous motor can be a type of 3-Phase AC motor, or not.A synchronous motor is defined by the period of the rotor being synchronized with the frequency of the stator windings' current. The stator windings might be 3-Phase or not (2-Phase would work).Also synchronous motors are not the only type of 3-Phase AC motors. An induction motor could also be 3-Phase AC and has a few advantages and disadvantages over a synchronous motor.
How do you convert or rewire a 20HP 3 phase motor to single phase motor?
The winding design of the motor will not economically allow this to work. You would have to drive a 3 phase generator to supply it.
What are the advantages of three phase motor over the single phase motor?
A 3-phase motor produces a steady torque that does not pulsate. A 3-phase motor starts turning in the right direction when switched on without the need for a separate starting winding.
