Lights flickering when washer is in spin cycle

[1haz]

Service call today where homeowners lights (every light) in her condo flickers when the washer is in the spin cycle. This is the only thing that makes them do this. Checked the meter, all neutrals/grounds inside main panel, pulled alot of plugs out checking them. Tighen all wires in panel, new breaker on washer circuit. Still does it. Plugged my auger drill in same outlet and no flickering. Thinking it may be the washer. Any other ideas?

 

[Jraef]

Service call today where homeowners lights (every light) in her condo flickers when the washer is in the spin cycle. This is the only thing that makes them do this. Checked the meter, all neutrals/grounds inside main panel, pulled alot of plugs out checking them. Tighen all wires in panel, new breaker on washer circuit. Still does it. Plugged my auger drill in same outlet and no flickering. Thinking it may be the washer. Any other ideas?

Possibilities:

• Loose connection inside of the washer, only evident with the high vibration of the spin cycle.
• Washer uses a VFD / ECM for the drive motor and at high speed, it spews a lot of harmonics that are interacting with her lighting system.

 

[kwired]

Service call today where homeowners lights (every light) in her condo flickers when the washer is in the spin cycle. This is the only thing that makes them do this. Checked the meter, all neutrals/grounds inside main panel, pulled alot of plugs out checking them. Tighen all wires in panel, new breaker on washer circuit. Still does it. Plugged my auger drill in same outlet and no flickering. Thinking it may be the washer. Any other ideas?

Plug a 1000-1500 watt load in instead of your unloaded drill when doing load testing.

Temporarily move the washer circuit to the other bus in the panel and see if it still does the same thing, or even if it moves the effect to different lights.

Newer washers with electronic motor drives could possibly put too much distortion on the line and impact LED lighting performance?

 

[JFletcher]

I can see my lights flicker when my washer is on the agitate cycle but not the spin. How heavily was the washer loaded? Im thinking overload may cause higher amp draw and perhaps enough voltage drop to be visually noticeable. I have incandescent lights and can see this with the vanity lights in the bathroom where it's brightest.

eta: I bet if you ran a 1 1/4" auger bit into a 6 x 6 on that circuit and toggled the trigger you could get nearly the same effect as her washer. Spin cycle could do it with a load of heavy towels tho my machine bangs LOUDLY long before I noticed any lights flickering.

 

[kwired]

I can see my lights flicker when my washer is on the agitate cycle but not the spin. How heavily was the washer loaded? Im thinking overload may cause higher amp draw and perhaps enough voltage drop to be visually noticeable. I have incandescent lights and can see this with the vanity lights in the bathroom where it's brightest.

eta: I bet if you ran a 1 1/4" auger bit into a 6 x 6 on that circuit and toggled the trigger you could get nearly the same effect as her washer. Spin cycle could do it with a load of heavy towels tho my machine bangs LOUDLY long before I noticed any lights flickering.

Agitate cycle does make sense for light flicker as the load constantly varies when the washer is agitating. spin cycle may have a higher draw but is not a constantly changing load.

 

[JFletcher]

Agitate cycle does make sense for light flicker as the load constantly varies when the washer is agitating. spin cycle may have a higher draw but is not a constantly changing load.

Yeah a heavy load starting and stopping or going no/low load to full causes a faint but noticeable cyclic flicker in my lights. I havent noticed it in the kitchen, bedrooms or outside but they arent nearly as bright as the bathroom vanity. I'm thinking CFL or LED wouldnt flicker, at least not to the degree that incandescents do it.

1Haz is on the right track; the problem is in the washer or its operation. Only problem I could see electric-wise is the circuit the washer is on is already loaded a good amount, is on #14, and/or is a long distance from the panel, exacerbating the voltage dips.

First thing I'd do is run it w/o a load in it thru the cycles and see what happens.

 

[mbrooke]

Agitate cycle does make sense for light flicker as the load constantly varies when the washer is agitating. spin cycle may have a higher draw but is not a constantly changing load.

Especially if you have a dual action agitator:

The bottom fins will move back and forth, but the top auger will only move in the clockwise stroke. Each time the auger moves it puts very significant strain on the motor as its designed to drag clothes to the bottom of the wash basket. I had a washer like this and you could literally see all the lights in the home connected to the same phase as the washer pulsating.

Newer washers do it even more because they have a permanent split capacitor motor which mimics agitation by reversing direction hundreds of times a minute instead of the old fashioned gear case transmission which accomplished this with gears. Further spin is accomplished by gradually increasing the speed of the motor instead of using a clutch. See page 18 (3-1):

Drive System:

Motor- Bi-directional PSC (Permanent Split Capacitor) 120VAC. Agitation and variable spin speeds are accomplished by applying power in pulses.

http://www.msaworld.com/wp-content/uploads/sites/3/2014/08/VMW-Job-Aid-W10329932.pdf

Also see page 82 for the wiring diagram. The motor is thyristor fired, and speed and agitation is achieved by rapidly pulsing these semiconductor switches.


But to sum it up this may be completely normal or a problem depending on the make, model of the washer and the severity.

 

[mbrooke]

Wiring diagram showing triac fired PSC motor:

 

[retirede]

I have a Fisher & Paykel washer. It has no transmission. The motor is direct drive and is reversed rapidly by the drive during the wash cycle. I never thought much about it before, but I could see this potentially causing problems in a home with a substandard electrical system.

 

[mbrooke]

I have a Fisher & Paykel washer. It has no transmission. The motor is direct drive and is reversed rapidly by the drive during the wash cycle. I never thought much about it before, but I could see this potentially causing problems in a home with a substandard electrical system.

Certainly. Though my understanding is that F&P uses a 3 phase high frequency inverter system which drives the motor very smoothly and limits inrush both in the inverter itself and how the power is applied to the stator. On the other hand, many newer low and mid range washer uses an off the shelf permanent split capacitor motor where the triacs are simply either on or off, with each "on" cycle simply dumping line frequency 60Hz across the motor without any current limiting. Each time that happens there is significant inrush as compared to the intelligent VFD control system. You are literally turning a single phase line voltage AC motor on and off several times a second.

 

[kwired]

Certainly. Though my understanding is that F&P uses a 3 phase high frequency inverter system which drives the motor very smoothly and limits inrush both in the inverter itself and how the power is applied to the stator. On the other hand, many newer low and mid range washer uses an off the shelf permanent split capacitor motor where the triacs are simply either on or off, with each "on" cycle simply dumping line frequency 60Hz across the motor without any current limiting. Each time that happens there is significant inrush as compared to the intelligent VFD control system. You are literally turning a single phase line voltage AC motor on and off several times a second.

any electronic controlled motor is likely "soft started" and isn't as severe with starting surge current, but still you are constantly cycling the load level and could see some effects if you have a substandard supply or weak component somewhere in the supply. Even older washers that have constant speed motor and reverse via a transmission will still see current level cycle up and down each time it stops and then reverses the driven load.

 

[gar]

170808-2127 EDT

1haz:

I have to assume that the washer runs on only 120 V. I would also assume that the power company supply is a split phase center tapped transformer secondary.

The claim is "(every light) in her condo flickers". If we assume that lights are equally distributed between the two phases, and that probably none are on the washer circuit, then on this assumption if all lights flicker dim, then this could only occur from a power company transformer primary side problem. If some lights brighten while others at the same time dim, then there is a neutral problem from power company transformer to the main panel.

If the spin cycle does not stop and start the motor, then it is doubtful that current changes great than 10 A occur during spin. You can use the min-max mode of a current meter to monitor the washer current.

Also use a min-max voltmeter to monitor both incoming phases to neutral at the main panel. At my home main panel an approximate change of 10 A causes about 0.8 V between the loaded phase hot line and neutral. This voltage change I can not easily see when looking at an incandescent bulb on the same phase. The other phase to neutral read about 0.3 V change for the about 10 A load change on the opposite phase. This is consistent with what I would expect. The difference in the two readings is because the unloaded hot phase wire has no current change and only the neutral current change is seen.

I would expect you have several volts change for the ordinary person to notice flicker.

Also note that the loaded side dims with an increase load, while the unloaded phase brightens. Unchanging absolute load on either phase has no affect on flicker.

 

[mbrooke]

any electronic controlled motor is likely "soft started" and isn't as severe with starting surge current, but still you are constantly cycling the load level and could see some effects if you have a substandard supply or weak component somewhere in the supply. Even older washers that have constant speed motor and reverse via a transmission will still see current level cycle up and down each time it stops and then reverses the driven load.

True- however it tends to be more severe with thyristor motors than VFDs, and when dealing with the spin cycle you will notice it much more than a clutch machine in terms of it lasting past the initial start.