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Mike G.
Mike G., Master Electrician
Category: Electrical
Satisfied Customers: 7094
Experience:  Proven Professional 46 years Experience
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I've got a customer with a 3 hp 1 phase 208/230v 16 amp pump motor that he replaced F

Customer Question

I've got a customer with a 3 hp 1 phase 208/230v 16 amp pump motor that he replaced Friday. Within 10 seconds of firing the motor, the capacitor fried! The motor continued to run fine and didn't trip the 20 amp breaker. I went out to him on Friday with a replacement capacitor, switched it out; fired it and, again within 10 seconds fried the second capacitor. We checked the voltage and was getting 124 and 125 v from each leg, with 14 and 15 amps respectively. Also replace the 5' whip from the breaker to the motor, just be safe. This morning I heard that the motor is fried and trips the breaker almost immediately when he tries to reset.
What should I/we be looking for or at?
Submitted: 1 year ago.
Category: Electrical
Expert:  Mike G. replied 1 year ago.
Hi, I'm Mike G and will be glad to assist you. Can you upload a picture of the nameplate and the wiring diagram for review?
Customer: replied 1 year ago.
Not at the property. What info would you like?
Expert:  Mike G. replied 1 year ago.
All the nameplate info and the wiring diagram. a picture of how it was wired would also be of help.
Customer: replied 1 year ago.
Who do I sent it to? (e-mail or text)
Expert:  Mike G. replied 1 year ago.
Use the paper clip icon on the toolbar if you have one or go to www.tinypic.com and upload it there (send the URL in a reply here).
Customer: replied 1 year ago.
https://us-mg6.mail.yahoo.com/ya/download?mid=2%5f0%5f0%5f1%5f671227%5fADHsw0MAABEXVbawJwC7gPCQSQw&m=YaDownload&pid=2&fid=Inbox&inline=1&appid=yahoomail
Customer: replied 1 year ago.
As far as the wiring, there is only 2 leads to connect; Line 1 and Line 2 and the ground, as shown in the wiring diagram.
Expert:  Mike G. replied 1 year ago.
Is the motor 120/208/230V. I need either the model number or all info on the nameplate.
Customer: replied 1 year ago.
The motor is 208/230v as I said in the original question. 1 phase amps 15.0-13.3. Open drip, 3,450 rpm Insulation class B continuous use. I'm guessing the picture didn't come through?
Expert:  Mike G. replied 1 year ago.
No picture, no model number.
Customer: replied 1 year ago.
The motor is a Century SQ1302V1 . In the 3 hp category, they do not offer a 110 option.
Customer: replied 1 year ago.
Can I text or e-mail the picture to you? Tiny pic is not cooperating.
Expert:  Mike G. replied 1 year ago.
It would work if you only give me the model number. I could look it up and have the info to work with.
Customer: replied 1 year ago.
I did - it is a Century SQ1302V1 3 HP Pool motor. Sent it just before your post of "No picture. No model number"
Expert:  Mike G. replied 1 year ago.
Got it. I'll be back a little later. Going to dinner.
Expert:  Mike G. replied 1 year ago.
OK, here are the facts.1) What is the distance to the panel and the wire size. Voltage drop may be part of the problem.2) A 16A motor load needs to be on a bigger circuit to allow for the inrush when starting. The listings online have different FLA ratings, should use the biggest.3) You gave me voltage reading of 124 amd 125V and the amperage for those readings. I need a voltage reading hot to hot and amperage for 230V not 120V, hot to ground for consideration.
Customer: replied 1 year ago.
As I said earlier, the whip from the circuit breaker to the motor is 5'. I also said that the hot to hot was 214v. Amps were coming through at 0.7.
Expert:  Mike G. replied 1 year ago.
None of your replys mentioned the 214V and .07A can't be real. Is the breaker for the pump in a sub panel and how far away is the main equipment, if so?
Customer: replied 1 year ago.
The breaker for the pump IS on a sub-panel. The main panel is about 40' away.
Expert:  Mike G. replied 1 year ago.
What size is the wire?
Customer: replied 1 year ago.
I'm going to say 10 gauge from memory, but I'm not there. They are 25 miles from me.
Expert:  Mike G. replied 1 year ago.
#!0 wire is OK One last thing, what size was the motor that this one is replacing. The original motor.
Customer: replied 1 year ago.
Let me re-state - from memory, the line into the sub panel (from the main) was 10 gauge. The whip is 14 gauge (from the breaker to the motor).
Expert:  Mike G. replied 1 year ago.
The wire size is too small on the whip. The 214V reading, if taken before starting the motor only says there is a low voltage the will increase when the motor starts. You need #10 wire to the pump motor on a 30A breaker to resolve the issue.
Customer: replied 1 year ago.
The motor was replaced like-for-like; 3 hp 1 phase 208/230v 3450 rpm 1.15 SF. We don't play mix n match on pumps because of the hydraulics involved. Additionally, the motor that we replaced was functioning when it was replaced. The bearings were trashed because of a failed shaft seal; it was NOT burned up.
Expert:  Mike G. replied 1 year ago.
That may very well be, I'm only working with actuals you have on the installation. Your problem is voltage drop as I see it. The connections are simple and this is the second motor replacement having issues. Nothing else it could be.
Customer: replied 1 year ago.
All due respect to your title, Mike, but there are thousands (literally) of pumps with 5 and 10' runs from the breaker to the pump running #14 and #12 and most ARE on 30a breakers.. #10 is being used on 3 phase and much longer runs. I find it extremely hard to believe that through the 4 counties I work in, that EVERY inspector in EVERY county passed EVERY installation on code inspection when they were originally permitted???
Why did the original configuration last over 4 years?
Expert:  Mike G. replied 1 year ago.
One more thing. Check all connections all the way back to the service equipment, check the jaws of the breakers and their buss positions for signs of arcing or corrosion, which could lead to a low voltage condition. I can only call it as I see it. If you have a difference of opinion, no problem. You might consider that possibly I'm right. If you want I'll opt out and you can get a second opinion on your problem.
Customer: replied 1 year ago.
I totally agree checking the connections at ALL ends - first thing I had him look at AS he was replacing the whip. Also thought he might have some aluminum wiring because of the age of the property, but NOT the case. All my basic 'go-to's' are being de-bunked. That's why I'm here.
Expert:  Mike G. replied 1 year ago.
Well then you have nothing to lose by going with my suggestions. I can't think of anything else it could be.
Customer: replied 1 year ago.
There have been several comments on different posts made about power companies installing new transformers (to the properties) that are intended to 'condition' or 'balance' the voltage to the property, while switching sub-stations. If am understanding the concept, this seems to be resulting in lower than desired voltage, in some instances. Are you aware of this anomoly and is my assessment anywhere near accurate?
Expert:  Mike G. replied 1 year ago.
Voltage eading from the feed side of the main, the buss after the main, the main for the sub pnel and the disconnect before and when starting the motor. Annomolies found can be addressed. A bad connection on a phase conductor at the transformer may have brought this on. All you can do is test for issues.
Expert:  Mike G. replied 1 year ago.
Voltage reading from the feed side of the main, the buss after the main, the main for the sub pnel and the disconnect before and when starting the motor. Annomolies found can be addressed. A bad connection on a phase conductor at the transformer may have brought this on. All you can do is test for issues.
Customer: replied 1 year ago.
I appreciate your time. Thank you.
Not arguing - looking for the 'magic' answer that everybody else is looking for.Again, thank you for your time.
Expert:  Mike G. replied 1 year ago.
You're welcome. Let me know how you make out with it. Good Luck.

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