Process of elimination, to rule in the switch as culprit, remove the wires on the line side and connect them to the load side. The motor should run , assuming you don’t have other issues. Just don’t leave it run and overpressure, oh, and disconnect the power supply while working on it.
The start capacitor for one model of a Bostitch air compressor is shown below. To see if your capacitor is within specification set the meter to the capacitance mode and apply the test leads to the terminals – it will take a few seconds as the meter is actually charging the capacitor and then reading it in farads. If you have any questions regarding how to test capacitors on air compressor motors then please leave a comment below with a photo if applicable so that someone can help you!
If the capacitor of the motor of your air compressor is damaged, then the motor takes in an unusual amount of power while starting. If there are internal problems in the motor, you can always rebuild or replace the motor to solve the air compressor electric motor problem. Finally, hope that this air compressor motor troubleshooting guide was helpful for you to find out the problem of your air compressor motor and fix it.
This article gives a description of electric motor capacitor test procedures to determine if a capacitor is damaged or working normally & test procedures to measure the capacitor’s capacitance or microfarads, MFD, or uF to determine if it is working within its rated capacitance range. This article series gives electric motor start-run capacitor and hard-start capacitor installation instructions to get a hard-starting air conditioner compressor motor, fan motor, refrigerator, or freezer compressor or other electric motor going. Discussed here: description of electric motor capacitor test procedures to determine if a capacitor is damaged or working normally & test procedures to measure the capacitor’s capacitance or microfarads, MFD, or uF to determine if it is working within its rated capacitance range.
The start capacitor cover on your compressor motor may look the same as the one shown in the photo, or might differ slightly. If the compressor motor start capacitor has failed, the power supply to the motor stops there, and the motor will not start. If you’ve checked the capacitor and it’s good, then possibly the electric motor itself has failed, particularly if, when you power up the air compressor with the tank empty, and power flowing to the tested start capacitor, your compressor motor makes no sound at all.
Air conditioning compressor motors are very simple to diagnose but can be confusing. Grounded Winding – This is similar to the shorted winding but the wire with the broken insulation is making electrical contact with the compressor casing or ground. Note – If you suspect you have an open winding, make sure the compressor isn’t overheated.
how to test air compressor electric motor Related Question:
How do you tell if a compressor is burnt out?
But perhaps the simplest method is the “odor test.” The smell that comes when a hose is connected to the system is both pungent and revealing. Once sniffed, it’s never forgotten and is one of the best indicators of a compressor burn-out.
How do you check motor continuity?
AC Motor Winding Continuity Test 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.
What is the most common cause of motor failure?
Low Resistance. The most common cause of motor failure, and arguably the most difficult to overcome, is low resistance. Low resistance is caused by the degradation of the insulation of the windings due to conditions such as overheating, corrosion, or physical damage.
How do you test a single phase electric motor?
With a multimeter, measure the resistance between motor frame (body) and earth. A good motor should read less than 0.5 ohms. Any value greater 0.5 ohms indicate trouble with the motor. For single phase motors, the expected voltage is about 230V or 208V depending whether you are using the UK or America voltage system.
Can a compressor motor be repaired?
Air compressor repair can be simple. It’s actually venting the residual pressure from the compressor head so the motor doesn’t have to work as hard on the next startup. The air compressor unloader valve is usually built into the pressure switch assembly.
Why did my air compressor stop working?
If your compressor is failing to work properly, it could simply be from a nearly empty oil tank. Power switch failure — When the compressor fails to power on, it could be due to a lack of contact between the pressure switch and inner circuitry. This can possibly be remedied with adjustments to the pressure switch.
Why does my air compressor not start?
If the compressor won’t start with air in tank, replace the check valve. If the compressor won’t start with an empty air tank, replace the pressure switch if it isn’t activating the pump motor. Replace the pump motor if it doesn’t start when activated by the pressure switch.
How do you know if a motor is bad on a multimeter?
With a multimeter set to low ohms (usually 200), test between each winding terminal and the metal casing of the motor. If there is any reading on any of these then the motor is bad, do not use it. You may find that when it runs ungrounded that the casing becomes live at up to supply voltage.
What is the first thing to do in testing any motor?
To begin an evaluation, check in first on the basic measures of motor performance: current levels, power, voltage, and resistance. Preliminary tests are generally done using the ubiquitous multimeter, which can provide diagnostic information for all kinds of motors.
What causes an electric motor to stop working?
Low resistance is the most common cause of failure in electric motors. It is also often the most difficult to overcome. Under conditions such as overheating, corrosion or physical damage, degradation of the insulation of the internal windings of the motor may occur.
How many ohms should a capacitor have?
A normal capacitor would have a resistance reading up somewhere in between these 2 extremes, say, anywhere in the tens of thousands or hundreds of thousands of ohms. But not 0Ω or several MΩ. This is a simple but effective method for finding out if a capacitor is defective or not.
How do you identify a starting capacitor and a running capacitor?
The voltage classifications are 370V and 440V. Capacitors with ratings above 70 microfarad (uF) are starting capacitors. Run capacitors are designed for continuous duty, and are energized the entire time the motor is running. Single phase electric motors need a capacitor to energize a second phase winding.
