3 Phase Compressor Internal Troubleshooting: Checking a Short to Ground- Turn the Power off. Remove all of the wires off the terminals. Take an Ohmmeter and attach one probe to T1 then take the other probe and touch it to the metal housing of the HVAC system, the housing of the compressor, or the copper pipe.
What does it mean when a compressor is grounded?
What does a grounded compressor mean? A "grounded compressor" or "compressor short to ground" means that an electrical winding inside the compressor has broken and hit the side of the compressor. This causes a direct short to ground, igniting the oil and causing a burnout. And, of course, the circuit breaker trips due to the sudden current surge.
How do I know if my electric motor is shorted to ground?
Touch the meter's second probe to one of the motor's wire terminals. Read the meter. The meter should read infinite. If not, then the motor's windings are shorted to ground. Repeat this step for each wire terminal.
How much does it cost to replace an AC compressor?
The cost of an AC compressor unit can range from $195 to $736 for the part itself, while the cost for parts and labor can be between $376 to $986. This will depend on the model of car and how much work is involved in the repair, with some units being substantially more difficult to replace than others.
How can I tell if my compressor is grounded?
5:2811:06Testing if an HVACR Compressor is Shorted to Ground, Open, or ...YouTubeStart of suggested clipEnd of suggested clipSo the copper tube is a great spot to check to make sure that you're not short of the ground you canMoreSo the copper tube is a great spot to check to make sure that you're not short of the ground you can check any one of these wires as long as you've already checked the pairs.
What is the correct way to check a compressor motor for grounding?
0:2514:09Troubleshoot a Grounded (Shorted to Ground) Compressor - YouTubeYouTubeStart of suggested clipEnd of suggested clipToo much current because if it's just a slight over amperage or overload condition then generallyMoreToo much current because if it's just a slight over amperage or overload condition then generally the motor is gonna shut itself off via internal overload.
Should a compressor have resistance to ground?
You should have an infinite OL resistance to ground. A shorted motor will read 0 ohms across windings, to ground, or both. If it is both, you will need to replace the compressor.
How does a compressor ground out?
Compressor burnout is a very specific mode of failure that may be caused by high temperatures in the motor windings or discharge area of the compressor. High temperatures break down the motor winding insulation, which may cause a loss of electrical resistance and result in a short to the ground or even an open winding.
How do I test a 3 phase compressor?
2:193:49HVAC-How To Check The Windings Of a 3 Phase Compressor & Check ...YouTubeStart of suggested clipEnd of suggested clipHere's our light and we're gonna check across the three terminals. So let's start with any twoMoreHere's our light and we're gonna check across the three terminals. So let's start with any two between these two keep it on there we have a reading of 0.67 now between the next. Two.
How do you check if the motor is grounded?
2:253:46Basic Test to Check that AC Spindle Motors is Grounded - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo we'll hook the our ground clamp up to the motor. And we'll verify that we have a good ground byMoreSo we'll hook the our ground clamp up to the motor. And we'll verify that we have a good ground by touching the frame. And we do. So then we'll go to you. And we know you as grounded.
Can you fix a grounded compressor?
Just to answer your literal question, compressors are not field serviceable. If your compressor has a problem, the only option is to replace it. Final result: the compressor is just fine. The first tech didn't bother to examine the whip, which was shorted phase-to-phase just as it exited the disconnect box.
Should there be continuity between compressor windings?
A: No, not necessarily. If the internal overload protector opened, leave enough time for it to reset before checking the valves. An open overload protector could give the same readings as open windings, leading to a misdiagnosis and the condemnation of a good compressor.
How do I test a compressor with a multimeter?
6:018:12How to Test For BAD Compressor. Ohms Test With MultiMeter - YouTubeYouTubeStart of suggested clipEnd of suggested clipWe're gonna take a reading from common to run we're gonna take our multimeter we're gonna put oneMoreWe're gonna take a reading from common to run we're gonna take our multimeter we're gonna put one lead uncommon. One lead on run and then we want to see what the reading is on our multimeter.
How many ohms should a compressor have?
The lowest reading should be below 10 ohms (this is the run winding). The second highest reading should be about 2-4 times higher than the lowest reading (this is the start winding).
What is the most common cause of compressor failure?
AUTOPSY OF A COMPRESSOR: The two most common causes of compressor failure are loss of lubrication and slugging, according to Brainerd Compressor Inc.
3 phase compressor check
Hi : How would i check a three phase operated compressor and prove it bad?Check each terminal s, r &c to the housing for a tone or high ohm reading? Thanks Rick.
I've had it!!!!!!!
How come all you guys are so quick to jump all over some one looking for some guidence? Is it because everyone is so full of themseves or just rude?I bet most of you guys are the type of person who will jump over a pregnant woman in a subway fire to get to the exit.Oh but wait there is no subways in the south.Any way to hell with this site!!!!!
professional attitude
Lets say the three phases are L1 L2 L3, check to see if any are grounded to each other and then check if any of the phases are shorted to ground, if any have a dead short then it's bad as far as a high imped short you will need to meg out the compressor using a megger.
wasn't thinking work on all phases
Agreed 100%! Knowledge is everything in this trade and the more your willing to educate yourself the easier your job will become.
attitude
Where's #3??? How will we ever know the whole story??? It's an awful day!!!!!!! Our numbering system has completely tanked!!!! EEEGAAADDDDD!!!!!!! Run for the hills!!! It must be BO's fault (everything else is)...
Step 1
Disconnect the electricity to the motor. If the motor's appliance plugs into a wall receptacle, then remove the plug from the receptacle. If the motor operates an appliance that connects to a circuit breaker, like an air-conditioning compressor-motor, then turn off the appropriate circuit breaker.
Step 2
Access the motor's electrical connections and its case. Each type of motor application requires its own type of access. For example, pull the back panel off of a refrigerator to reach the condensing fan motor or disconnect a ceiling fan to reach its motor.
Step 3
Label each motor wire with a masking tape tag and a pencil. Make notes on the tape identifying the wire's terminal. In most cases, wire terminals have identification labels stamped next to the terminal.
Step 4
Disconnect all motor wires. If the motor wires use slide-on terminal connectors, then grasp the terminal connector with needle-nose pliers and pull it off the wire terminal. If the motor uses screws to hold the terminal connectors in place, then loosen the screw with the correct screwdriver, often a Philips-head, and remove the terminal connector.
Step 5
Turn a multimeter or ohmmeter to its highest resistance setting. A multimeter has voltage, amperage and resistance settings. Ohmmeters read resistance.
Step 6
Touch one of the meter's probes to the motor's case. If the manufacturer painted the motor's case, then scrape the paint from a small area with a screwdriver and then place the meter probe on the bare spot.
Step 7
Touch the meter's second probe to one of the motor's wire terminals. Read the meter. The meter should read infinite. If not, then the motor's windings are shorted to ground. Repeat this step for each wire terminal.
