# Light Flicker and frequency change with 3-phase well



## valeech (Jun 21, 2011)

Hi,

I am new here and did some searching but didn't find something close to what I am dealing with so don't flame me too bad 

I am working at a customer's house who has a Subdrive 150 constant pressure well pump (3-phase) connected to a 20A circuit via a 100A sub panel in his basement. Keep that in mind.

The homeowner called to complain that at odd times the lights in the master bath (PAR30 incandescent floods on a dimmer) would flicker sporadically. They also have some very high end A/V equipment and complained that the video and audio would flicker in and out at random times too. 

In troubleshooting, I was able to narrow both problems down to the well. The lights only flicker when the well pump is running and the A/V equipment only has issues when the pump is running. 

I measured voltage at the A/V (20A) circuit while the pump was off, 120VAC. When the pump was on, 120VAC. So I thought ok, frequency? I checked, with pump off 59.99. With the pump on, the frequency never drops below 59.99 but it bounces all over the place as high as 118! 

I test other large appliances to include AC and there is no problem. 

Any idea why the well pump on 3-phase would cause the frequency fluctuation? I am pretty sure this is what is causing the A/V equipment to crap out but I am wondering is it the cause for the flickering lights? I am thinking the well pump might be bad...

Thanks in advance!


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## Jlarson (Jun 28, 2009)

Sounds like the SubDrive is on it's way out, I've seen similar problems from them before. You can maybe bypass the drive and start the motor across the line with a pressure switch and a starter if it's gonna take a while to get a new drive so they aren't without water.


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## HARRY304E (Sep 15, 2010)

valeech said:


> Hi,
> 
> I am new here and did some searching but didn't find something close to what I am dealing with so don't flame me too bad
> 
> ...


Is the 100 amp panel 3 phase?


Can you get another pump motor?

I don't see how the motor is changing the frequency:blink:


Welcome to the forum.:thumbup:


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## steelersman (Mar 15, 2009)

who has a 3 phase motor at a residence? You sure about this? It's on a 3 pole breaker?


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## Jlarson (Jun 28, 2009)

Actually I take back what I said about bypassing the the SubDrive and starting it DOL, they could be feeding it single phase and then they have a 3 wire 3 phase motor down hole running off the SubDrive.


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## valeech (Jun 21, 2011)

HARRY304E said:


> Is the 100 amp panel 3 phase?
> 
> 
> Can you get another pump motor?
> ...


Thanks for the welcome! The sub panel is single phase. 



steelersman said:


> who has a 3 phase motor at a residence? You sure about this? It's on a 3 pole breaker?


It is definitely 3 phase. Check out these photos:

http://www.flickr.com/photos/[email protected]/5857448787/in/photostream

http://www.flickr.com/photos/[email protected]/5857449175/in/photostream/

I spoke with Franklin Electric today about their Subdrive and they mentioned that the frequency issue is because of RFI bleeding. They think the issue is with the ground. They suggested checking to verify the ground exists from the pump to the Subdrive, from the Subdrive to the panel. I'll check that tomorrow.

Thanks for the help!


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## nrp3 (Jan 24, 2009)

The well on the house that I wired for geo thermal has just that, some sort of vfd that takes a single phase input for a three phase well pump. Different unit than that one though.


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## Jmohl (Apr 26, 2011)

All VFDs are capable of running a three phase motor on single phase input power. That said, you could get one from Automation Direct for around $600, program it for single phase input, 3phase 230 out. Ramp accel, analog input from the Franklin unit with the scale factor set accordingly and rock on... about 1500 cheaper than from Franklin, and a lot easier to get.:thumbsup:


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## valeech (Jun 21, 2011)

Jmohl said:


> All VFDs are capable of running a three phase motor on single phase input power. That said, you could get one from Automation Direct for around $600, program it for single phase input, 3phase 230 out. Ramp accel, analog input from the Franklin unit with the scale factor set accordingly and rock on... about 1500 cheaper than from Franklin, and a lot easier to get.:thumbsup:


That sounds great, but I have no idea what you just wrote 

You lost me here:


Jmohl said:


> Ramp accel, analog input from the Franklin unit with the scale factor set accordingly and rock on...


Are you saying I should just copy those settings from the Franklin unit to the new one?

Thanks!


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## valeech (Jun 21, 2011)

Here's an update if you're interested.

I started to investigate the ground for the well since the Franklin guys thought that might be the problem. The connection goes like this:

Well driver -> Basement 100A sub panel -> Garage sub panel -> ATS -> Utility

The ground was good all the way until the ATS. The ATS is used as the service entrance device so the ground should be bonded to the neutral. It was not! I didn't have any #6 on me so I twisted two #10 together and bonded the neutral to the ground. 

I went back in the house, tested the frequency when the well pump was running and it still bounced around but not nearly as much as before. It would go from 60 to 70Hz. Before it went as high 118 Hz! 

Could the gauge of the wire be an issue at this point? I plan on putting #6 in as the bonding jumper but I am wondering if that will fix it completely.

One more thing. The Franklin guy mentioned that a lot of times this RFI bleeding happens when other systems "invade their space." One example he gave was when a satellite wire is run too close to the power wire of the well. The well will bleed RFI into the satellite cable and if the satellite isn't grounded properly it will act as one huge antenna.

Well, it just so happens this house has a satellite system. Now the satellite does not run anywhere close to the well power line, except in the basement. The SubDrive 150 unit is about 15 feet from a coax distribution panel where the satellite comes in. So, for grins I decided to see how the satellite was grounded. It has a ground wire going to an outside spigot. the bad news is, the spigot is copper through the foundation wall but then turns into CPVC. So the satellite is not grounded at all. I plan on fixing this in the morning however, there is no place for me to actually get back to ground! NEC says the ground must be as straight as possible. Well, the ground rod is on the opposite side of the house (7500 sq ft). I could drop a new ground rod but then I have to bond that to the current ground rod all the way around. Do you guys think it meets code to run a #10 back to the basement sub panel ground about 25 feet away and connect that to the satellite ground block?

Sorry for the long winded messages


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## Jlarson (Jun 28, 2009)

Huh, that's a new problem with those units for me, thanks for following up.


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## BBQ (Nov 16, 2010)

valeech said:


> So I thought ok, frequency? I checked, with pump off 59.99. With the pump on, the frequency never drops below 59.99 but it bounces all over the place as high as 118!


I am having a real hard time believing this pump is driving the grid frequency up or down or is this measurement between a drive and the pump?


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## Jlarson (Jun 28, 2009)

Valeech, you're measuring frequency on the circuit feeding the AV equipment right? What are you measuring between, hot and ground, hot and neutral, neutral and ground, and what's the voltage between those 2 points?


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## guest (Feb 21, 2009)

BBQ said:


> I am having a real hard time believing this pump is driving the grid frequency up or down or is this measurement between a drive and the pump?



Bob, it is VERY easy to impress a higher frequency waveform atop another. (That's how audio works in many respects, a complex waveform of many frequencies.) 

And don't forget that utilities used to inject a higher frequency to trigger devices to cut off water heaters and other energy hog loads. For example: 






That is in New Zealand. 

VFD's generate all kinds of RF noise..try to use an AM radio next to one. 

So I am not the least bit surprised that this pump drive is basically injecting a higher frequency back into the line. I am willing to bet, however, that it is a weak signal and not detectable from any great distance.


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## valeech (Jun 21, 2011)

Jlarson said:


> Valeech, you're measuring frequency on the circuit feeding the AV equipment right? What are you measuring between, hot and ground, hot and neutral, neutral and ground, and what's the voltage between those 2 points?


I have measured the frequency at 3 different circuits: The A/V equipment circuit which is just a few feet away from the well driver, a kitchen circuit on the first floor and a third circuit in the second floor master bath. All 3 circuits see the fluctuation in frequency when the well is running. In fact, there is a dimmer for lights in the master bath. Those lights flicker when the well runs.

I am measuring between neutral and hot on all 3 circuits. The voltage is an interesting question. Before I bonded the ground the voltage at all three circuits was a steady 120. Once I bonded the grounds, the voltage is steady at 123. There is never a drop in voltage when the well starts or stops.

Should I measure anything else? Would it help if I post some videos of the situation? I'm not crazy, really


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## valeech (Jun 21, 2011)

mxslick said:


> That is in New Zealand.


That is a cool video!


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## Jlarson (Jun 28, 2009)

Yeah sounds like you're seeing what mx is talking about. You're just using a dmm frequency counter so its just measuring the amplitude it "sees". In a situation like this I'd usually break out an o scope or PQ instrument and look at the waveform.

Sent from my Droid


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## nitro71 (Sep 17, 2009)

Does the problem only exist with the loads off the sub panel? If it's only those loads I'd scrutinize the conections, neutrals, bonding in that panel.


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## valeech (Jun 21, 2011)

nitro71 said:


> Does the problem only exist with the loads off the sub panel? If it's only those loads I'd scrutinize the conections, neutrals, bonding in that panel.


The problem exists throughout the house; on circuits off of the basement sub panel where the well is connected and off the sub panel in the garage where the rest of the house is wired.


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## steelersman (Mar 15, 2009)

Hey VAleech, what part of VA are you located?


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## valeech (Jun 21, 2011)

steelersman said:


> Hey VAleech, what part of VA are you located?


Not too far from you. Manassas PW Parkway and Hoadly Rd.


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## Jlarson (Jun 28, 2009)

Putting an EMI/RFI filter (like this http://www.alliedelec.com/search/productdetail.aspx?SKU=3110126#tab=Specs) on the drive input and a load reactor on the output would probably almost totally eliminate this problem.


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## steelersman (Mar 15, 2009)

valeech said:


> Not too far from you. Manassas PW Parkway and Hoadly Rd.


Damn dude right around the corner.....:thumbsup:


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## valeech (Jun 21, 2011)

Jlarson said:


> Putting an EMI/RFI filter (like this http://www.alliedelec.com/search/productdetail.aspx?SKU=3110126#tab=Specs) on the drive input and a load reactor on the output would probably almost totally eliminate this problem.


That's what I was wondering. It's not too expensive I may just give it a try...


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## TundraJD (Jun 20, 2011)

valeech said:


> That's what I was wondering. It's not too expensive I may just give it a try...


What are those filters

Sent from my iPhone using ET Forum


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## Jlarson (Jun 28, 2009)

TundraJD said:


> What are those filters


They are some inductors and capacitors put together, sometimes a bleeder resistor too to discharge the caps. They work by having a large reactive component to their impedance, so to high frequency noise they look like a high resistance so it reduces that noise.


I struggle to write stuff like that in a short and correct as possible way. I don't have the attention span for typing long drawn out posts :laughing:


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## hardworkingstiff (Jan 22, 2007)

My thoughts:

Did this ever work correctly or is this a new problem?

If it is a new problem, then installing a filter is just treating the symptom and not the problem.

In the 90's Franklin started using a variable speed pump and controller for submerged pumps at gas stations. The controller used frequency modification to control the pump output. They had a lot of problems with data circuits at gas stations that were tracked down to the FE Petro (Franklin's fuel division) IST controller. They denied a problem at 1st, but after some years, the problem quit occurring. 

My guess is your controller's filtering devices are failing and that's why you are having the symptoms you are having. The filtering failure (if that's what it is) shouldn't have any affect on the pump operation, just imposes something like I think you are seeing). I have no idea on how to check that, just throwing out my 2 cents.


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## Jlarson (Jun 28, 2009)

Jlarson said:


> I struggle to write stuff like that in a short and correct as possible way. I don't have the attention span for typing long drawn out posts


I'm gonna attempt to go into more detail about how the filter could solve the problem and how the problem _might_ not be failing drive components. In a paragraph or less though cause I'm already getting bored with myself :laughing:

So he's got a drive that has it's output run in probably a non metallic conduit or a non metallic cable. So there is no shielding, there's gonna be some stray capacitance to ground there, the output probably runs near plenty of other stuff in the basement. The EMI filter provides a path for the noise to get back to the drive through capacitors connected line to ground.


I'm starting to think I might have been paying attention when we learned about common mode noise and low pass filters in class


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## hardworkingstiff (Jan 22, 2007)

Jlarson said:


> I'm gonna attempt to go into more detail about how the filter could solve the problem and how the problem _might_ not be failing drive components. In a paragraph or less though cause I'm already getting bored with myself :laughing:
> 
> So he's got a drive that has it's output run in probably a non metallic conduit or a non metallic cable. So there is no shielding, there's gonna be some stray capacitance to ground there, the output probably runs near plenty of other stuff in the basement. The EMI filter provides a path for the noise to get back to the drive through capacitors connected line to ground.


To add to what you are saying, the fact he modified the grounding system and had changes does indicate that is the 1st place to look.


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## Jlarson (Jun 28, 2009)

I really wish the US would get on board with the Europeans in regard to drives and EMI stuff related to them. They have standards to eliminate or at least reduce problems like this, requiring things like drive cable, filters, noise chokes, and reactors.


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## BBQ (Nov 16, 2010)

mxslick said:


> Bob, it is VERY easy to impress a higher frequency waveform atop another.


That is not what I said is it? 



me said:


> I am having a real hard time believing this pump is driving the grid frequency up or down


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## Jmohl (Apr 26, 2011)

valeech said:


> That sounds great, but I have no idea what you just wrote
> 
> You lost me here:
> 
> ...


You could. The parameter set is probably a little dif. but all in all, should be able to make a 300dollar automation direct work like the high dollar Franklin does. The grounding issue being discussed is also a biggie. EMI can wreak havok on you with these things especially if the control wiring( the PID loop) isn't shielded. As far as the terms I used, Ramping just means what it sounds like, a gradual or "ramped" acceleration as opposed to a "flying" start which behaves like an accross the line contactor. On Ramp, the drive will output a frequency and voltage that follows a linear path to the desired or preset speed. On Fly, the freq/voltage curve will be instantaneously output to the corresponding speed. Also keep in mind the Stop method used. A coasting stop essentially "opens the contactor" and lets the motor spin down on it's own. A ramped stop works like the ramped start and gradually decreases freq/volts down to stop. The time for all of these parameters also plays a role....


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## valeech (Jun 21, 2011)

hardworkingstiff said:


> My thoughts:
> 
> Did this ever work correctly or is this a new problem?
> 
> ...


I asked the same thing. The homeowner bought the house a year ago and said during their walk through with the previous homeowner they were told about the master bathroom lights dimming. The previous homeowner worked for the electrician that wired the house and the electrician told him that the dimming was fine; that it had something to do with the 3 phase conversion for the well but that it was normal.

So I am guessing this has happened since day one.


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## valeech (Jun 21, 2011)

Jlarson said:


> So he's got a drive that has it's output run in probably a non metallic conduit or a non metallic cable.


All true



Jlarson said:


> So there is no shielding, there's gonna be some stray capacitance to ground there, the output probably runs near plenty of other stuff in the basement.


The output comes out of the drive, drops about a foot and then punches through the foundation on the wall the drive is on. But there is plenty of stuff within 15 feet of the drive...


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## Jlarson (Jun 28, 2009)

valeech said:


> The output comes out of the drive, drops about a foot and then punches through the foundation on the wall the drive is on. But there is plenty of stuff within 15 feet of the drive...


Just to satisfy my brain, is the service UG and where is is in relation to the well cable?


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## valeech (Jun 21, 2011)

Jlarson said:


> Just to satisfy my brain, is the service UG and where is is in relation to the well cable?


It is underground and it should cross the well cable at close to a 90 degree angle.


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## Jlarson (Jun 28, 2009)

valeech said:


> It is underground and it should cross the well cable at close to a 90 degree angle.


That shouldn't be a huge deal then, if it was parallel it would be.


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## valeech (Jun 21, 2011)

I dug more into the homeowner's AV system to find out they have and HDMI system that uses Cat6 cabling to extend HDMI throughout the house. All of the AV equipment resides in the basement to include DirecTV receivers, AppleTVs and DVD players. Everything is in a rack about 15 feet away from the drive.

Now that I know this, I am thinking maybe the Cat6 cabling is picking up radiated EMI. So, I have some STP and ask the homeowner if I can try installing a new run to one of the affected TVs. After about 30 minutes, the cable is in and the problem is GONE! W00t!

I had thought about getting a filter and placing it on the drive but then it occurred to me that would only eliminate conducted EMI. Since this issue is radiated EMI, the filter won't help much. 

Anyway, the homeowner is very pleased... Now I just need to determine why the lights on the second floor flicker whenever the well runs. They are on a dimmer so maybe the conducted EMI is the issue too 

I want to say thanks to everyone for all of the help!


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## Jlarson (Jun 28, 2009)

Man I wish we had basements here cause I'd probably be getting a bunch of calls from HO's with this problem cause the well company put the drive inside and wired it with NM cable. :laughing:


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## kwired (Dec 20, 2009)

valeech said:


> Anyway, the homeowner is very pleased... Now I just need to determine why the lights on the second floor flicker whenever the well runs. They are on a dimmer so maybe the conducted EMI is the issue too


Possibly the dimmer is picking up the interference and passing it on through its output? I wouldn't think an incandescant light would otherwise be affected by this.


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## nrp3 (Jan 24, 2009)

Not knowing any better, thats how I wired the one I did for the geothermal house. Now that I look at Franklins website, its a newer version of what we've been talking about. 10-2 in 10-3 out, not any trouble for two years.


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## valeech (Jun 21, 2011)

Jmohl said:


> You could. The parameter set is probably a little dif. but all in all, should be able to make a 300dollar automation direct work like the high dollar Franklin does. The grounding issue being discussed is also a biggie. EMI can wreak havok on you with these things especially if the control wiring( the PID loop) isn't shielded. As far as the terms I used, Ramping just means what it sounds like, a gradual or "ramped" acceleration as opposed to a "flying" start which behaves like an accross the line contactor. On Ramp, the drive will output a frequency and voltage that follows a linear path to the desired or preset speed. On Fly, the freq/voltage curve will be instantaneously output to the corresponding speed. Also keep in mind the Stop method used. A coasting stop essentially "opens the contactor" and lets the motor spin down on it's own. A ramped stop works like the ramped start and gradually decreases freq/volts down to stop. The time for all of these parameters also plays a role....


Good to know. Thanks for the education :thumbsup:


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## valeech (Jun 21, 2011)

kwired said:


> Possibly the dimmer is picking up the interference and passing it on through its output? I wouldn't think an incandescant light would otherwise be affected by this.


That's what I'm thinking. Maybe a filter will help after all...


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