Ohm Readings Between Single Phase Induction Awning Motor Leads

An AC motor is not working like it'due south supposed to.  What do you practice?  Before replacing the motor, here are three ways to showtime troubleshooting your AC motor with a circuit tester.

Air-conditioning motors are the easiest type of motors to use.  Once ability is connected, an Air conditioning motor runs at a certain speed, and stops when the power is asunder.  When an Ac motor does not work, it's usually a power or wiring issue.  The play a trick on to identifying the crusade is to isolate potential issues.

What is a Circuit Tester?

A circuit tester (also known as a multimeter or multitester), is an electronic measuring musical instrument that combines functions from a voltage meter, an ohmeter, and an ammeter.  A typical circuit tester can measure voltage, resistance, and current in a circuit.

Starting time, Cheque the Basic Wiring.

When the motor is wired to a ability supply but not working, the kickoff thing you should do is check the wiring and ostend the required components for operation are in expert working condition.  Since there could be many components in the power supply circuit that can affect motor functioning, such equally relays, switches, or controllers, commencement with the most basic circuit equally possible.  This means connecting the AC motor and capacitor directly to the Air conditioning ability supply.  Once you confirm that the motor works, then you lot can add dorsum the components back.  This tin can help you verify if the components are skilful or bad.

TIP: Many Ac motor problems are acquired past bad components or incorrect wiring.  To brand troubleshooting easier, isolate the problem past troubleshooting the near basic circuit first.  One time that has been confirmed, and so test each private component as they're added back into the circuit.

iii Things to Exam with a Circuit Tester

Here are three ways to help find the crusade of an AC motor trouble.

one.  Compare  the applied voltage with the capacitor's terminal voltage.
2.  Verify if electricity is being conducted through the extension cable.
3.  Verify motor winding resistance.

Now nosotros will show you how to do each measurement, and what it confirms.

TEST one:  Compare Applied Voltage with Capacitor Terminal Voltage

If properly connected, the capacitor terminal voltage should be roughly 1.7 times the value of the ability supply voltage.  This confirms if the motor is receiving the proper voltage.

Using Circuit Tester A as shown in the above diagram, connect the cherry needle tip to the exposed portion of the ruby-red wire, and connect the black needle tip to the exposed portion of the blackness wire (and make sure there is good contact).  Confirm that the proper voltage is received at the motor.  Select Air conditioning voltage measurement mode (indicated by a "5"), on the circuit tester before starting.  If correctly connected, Circuit Tester A volition bear witness the power supply voltage.  For easy calculation, nosotros used a 100 VAC motor in the example, so 100 V would display on the circuit tester.

Using Circuit Tester B every bit shown in the above diagram, connect the red needle tip to the exposed portion of the ruddy wire, and connect the black needle tip to the exposed portion of the white wire.  If properly connected, the circuit tester will bear witness a value that'due south about 1.vii times the ability supply voltage.  In this example, 170 5 is measured.

Compare the two measured voltages.  The capacitor terminal voltage (scarlet/white) should be 1.7 times more of the ability supply voltage (blackness/ruddy).

What If I Don't Have a Excursion Tester / Multimeter?

To check whether whatever capacitor is connected in the circuit, rotate the motor shaft manually past manus while the power is on.  If no capacitor is connected, it volition rotate in the direction in which you apply the force.

REVIEW:

TEST 2:  Verify if Electricity is Conducted Throughout the Cable

A break in the connection of the motor'south circuit with its power supply can preclude the motor from working properly.  Doing the following measurement can confirm if a circuit is airtight or open up.

Do this with the power off.  Using Circuit Tester C and D as shown in the higher up diagram to examination the continuity of the cables from the motor to the power supply.  Use the blackness and red needle tips from the circuit tester to connect to the exposed connectedness points closest to the motor to the power supply.  If in that location's no suspension in the circuit, the excursion tester will beep.

TEST iii:  Verify Motor Winding Resistance

By measuring the motor's winding resistance and comparing the values to the motor'southward original designed values, the electric condition of a motor can be verified.

Before measuring, remove all additional components, such as extension cables and capacitor, from the circuit.  Switch the circuit tester to resistance value measurement way.  Using Circuit Tester Eastward and F in the to a higher place diagram, connect to the exposed portions of the pb wires directly from the motor.

We are in one case once more using a 100 V motor every bit an case (model: 2IK6A-JA).  For this item motor, the resistance readings from both Excursion Tester E and F should be 170 ohms.  If the winding is cleaved, the circuit tester will read a value of over several thousand ohms.  If there'south an internal short circuit, a value smaller than 170 ohms.  For other motors, delight contact the motor manufacturer to see what the designed values are supposed to be.  There is a tolerance of about +/-ten% for winding resistance.

What Exercise I Do If My Motor Does Not Pass These Tests?

When a motor doesn't piece of work, it could be a bad motor, or just a bad component making the motor look bad.  Examples are bad switches, relays, cables, or just the wrong voltage.  Doing these tests would provide valuable hints on what to gear up.  These are examples.

If your motor doesn't pass Exam one, check/supplant the capacitor or wiring.

If your motor doesn't pass Test 2, check/supercede the cable or connector.

If your motor doesn't pass Test 3, replace the motor.

Mechanical problems, such as a damaged ball bearing due to excessive radial or centric loads, can also terminate the operation of a motor.  To examination this, remove the motor and gearhead and attempt to rotate the shaft in both directions.  If the motor shaft or the gearhead shaft feels locked up without whatever load, then something is not right.  An aberrant noise or friction while turning the shaft could point damage or misalignment.  The best thing to do would be to supervene upon the motor and/or gearhead.

Another way to get a better motor troubleshooter is to understand the product meliorate.  Take a wait at these related posts to increase your production cognition of Air-conditioning motors (or talk to our technical back up engineers).

Topics: AC Motors, Troubleshooting

Written by

Johann Tang is a Product Specialist at Oriental Motor USA Corp. with over 15 years of knowledge and experience supporting applications of various types of electric motors, gearheads, actuators, drivers, and controllers.

lairdese1972.blogspot.com

Source: https://blog.orientalmotor.com/3-ways-to-troubleshoot-ac-motors-with-a-circuit-tester

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