Shawn Woodworth

[Shawn Woodworth]

OK. Thanks.

[Shawn Woodworth]

Hello Sam,

Can you be more specific?

REF:

Another trick for testing these MCU (inverter) outputs is by using a phase rotation tester, like this one: http://amzn.to/1AXyu6V

If you’re telling the MCU (via the CCU) to run and it’s not, you can use that phase rotation tester to see if the MCU is putting out all three phases to the motor. If not, no lights and bad MCU (assuming you have a good PWM signal at the MCU and that the MCU is getting a valid 120vac power supply). You can’t measure the MCU output directly but you can use that instrument to at least if the phase is present. And this is typical failure mode for MCUs: they fail in such a way that they completely stop putting out one or more of the phases to the motor so the motor can’t run (as opposed to putting out voltage that’s too high or a little too low).

I would like to learn the trick but am unfamiliar with the tool. Will there be three pins to port into?

Thanks,

Shawn W

[Shawn Woodworth]

Thank you Sam!

[Shawn Woodworth]

Thank You Sam,

This makes complete sense now. I will start utilizing this in my mental tool bag.

Regards,

Shawn W

[Shawn Woodworth]

Hello Samurai,

I’m interested in learning more abut how to conduct the testing of the MCU putting out all three phases to the motor. And, I would like to find an appropriate tool to do this. Below is a paste from your response with a link to a Amazon page for a phase rotation tester that has now expired. I have googled “phase rotation tester” but came up with Fluke 9040 Phase Rotation Indicator. It appears to do the same test: Key features
3 phase indication
Indication of phase rotation
Clear LCD display
No battery required.

How is this test conducted? the tool has three leads so I’m gathering that this would be hooked up to the MCU or the motor but not sure.

[Shawn Woodworth]

Hello Susan,

My question is related to how to implement this testing. I visualize running my blow dryer over the outside of a dishwasher water valve (for example) and just seeing plastic flaking off. It seems there would be more to this. I want to make sure I understand the procedure.

[Shawn Woodworth]

Hello Mrs. Brown,

Thank you for your feedback.

Shawn W.

[Shawn Woodworth]

Hello Mrs. Brown,

Thanks for your follow up. I have been using Google Chrome through the whole course up to this point. I tried Internet Explorer for the audio and it worked.

Thanks,

Shawn W.

[Shawn Woodworth]

Hello Sam,

Any feedback?

Shawn Woodworth

[Shawn Woodworth]

Hello Sam,

Sorry for the late response. Been pretty busy eating, drinking and sleeping appliance repair. I purchased the same sperry tester that the course recommends:

https://www.amazon.com/dp/B000RUL2UU?tag=mrssamskit-20&camp=0&creative=0&linkCode=as4&creativeASIN=B000RUL2UU&adid=0TRAQ3D8FDB38B7BW551&

I have run across this a few times now.

If you can find anything that would be great.

Shawn Woodworth

[Shawn Woodworth]

Hello Mrs. Samurai,

Ha Ha. I look forward to it now….I’m over thinking things again.

Thanks,

Shawn Woodworth

[Shawn Woodworth]

Hello Mrs. Brown,

I was afraid you were going to ask that, and had we been corresponding in real time during my original question I could probably answer that quickly. It is what prompted me to think that my original statement might be correct, although I felt it was incorrect and was trying to clarify. I’m sorry about the initial late follow up. As a bit of a reason, on a whim I applied for a few Appliance Repair jobs with an updated resume noting that I was a current student at Samurai Tech and it got me an interview and a job as an Appliance Repair Technician. Please thank the Samurai for developing such a fine program with a valuable reputation. I know it played a part in securing my new position. Not one of the 20 some technicians where I work have been through Samurai Training and the Manager seemed excited to have a Technician that will eventually have the Samurai skills. Apparently the owner has offered to pay for any of the Technicians to go through the MST Academy, but there have been no takers. I have been going through ride along training and gaining valuable hands on experience. There have been a lot of late days and human resource items to attend to so it has delayed my Samurai progress a bit. Although I feel I have a strong grasp on the Electricity portion of the training and could probably pass the Midterm, I want to make sure I take my time and know it inside and out as you and the Samurai suggest. I’ve been going over all the training and videos to ensure I can articulate with confidence all the topics and questions on the study sheet you have provided. I really want to move on to the next phase of the training so when I locate the section in the training I will let you know. I know you guys are always improving the program as needed.

I believe I have a good grasp on the current flow in parallel circuits and I will review the quiz questions for Units 4 and 5 again today. Thanks again for all your help and playing a part in getting my foot in the door to the Appliance Repair industry.

Best Wishes,

Shawn Woodworth

[Shawn Woodworth]

Hello Mrs. Samurai,

Your response helps and makes sense to me but I had found a statement from the training that current was the same in parallel circuits. However, based on your input it would be more accurate to say that “current varies in each branch of a parallel circuit depending on the total resistance of loads in each corresponding branch of the parallel circuit. However, the current will be the same outside of the branches.”

Would this be a more accurate statement then?

Thanks,

Shawn Woodworth

[Shawn Woodworth]

Hello Mrs. Brown,

Thank you, that link was helpful. I think I understand the concept. That’s nifty. Looks like it would be good for tight spaces.

Thank,

Shawn Woodworth

[Shawn Woodworth]

Thank you for your feedback Mr. Brown.

Example and point understood.

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