My mom called me yesterday...

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ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
... and she told me that ever since the electrical storm the other day which shut down the grid and caused her genset to come on, every time she turns on a light switch or appliance, a crackling sound emanates from the speakers of her stereo system. According to her, it never happened before the storm. Could something in the ATS, like maybe it didn't close its contacts well enough after the grid came back, be causing this? The generator isn't still running; I verified that much. She lives 300 miles from me, so I couldn't just run over and check it out myself. I told her to call the folks that installed her genset and tell them what she is hearing.
 

templdl

Senior Member
Location
Wisconsin
I would sow some concern about the house wiring and if there was a lightning strike close tat there may be damase do tho the electrical wiring, that the insulation somewhere may have been compromised.
I would go down to the distribution panel and turn off ever other breaker on onee rowas well as that breaker directly across from those isolating those circuits on repeated the same action causing the crackling. If the crackling persists turn those breakers back of and turn off the others repeating the same action that caused the crackling.
If turning off the set of breakers resulted in the crackling to go away then turn each breaker back on one at a time repeating the action that caused the static in the hopes of isolating he circuit causing the issue. Your inspection could also be directed towards those loads connected to that circuit.
Doing so will at least give you some direction or eliminate a posible issue.
 

James L

Senior Member
Location
Kansas Cty, Mo, USA
Occupation
Electrician
I would probably look at the sound source (receiver, cd, dvd, etc) and amplifier of the sound system. It could be clipping at the amplifier input due to damaged source component, something along those lines.

I wonder if the problem was present with the generator on, or only after the transfer back to POCO?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Possibly a neutral to ground SPD element has shorted out, causing switching transient to appear on an audio system ground connection.
Lift ground neutral bond at the main with power off and also interrupt the neutral, then look for continuity.
(Not a DIY test).
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
I would probably look at the sound source (receiver, cd, dvd, etc) and amplifier of the sound system. It could be clipping at the amplifier input due to damaged source component, something along those lines.

I wonder if the problem was present with the generator on, or only after the transfer back to POCO?

I agree as well that there may be an internal component that has suffered damage. I would lean towards a bad capacitor that filters power supply/audio before final amp stage.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
I agree as well that there may be an internal component that has suffered damage. I would lean towards a bad capacitor that filters power supply/audio before final amp stage.
So why would it make noise whenever a wall switch to a light somewhere else in the room is turned on?
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
Yes, the random frequencies that can be emanated by the arc within the switch (EMI) or spike on electrical circuit by turning appliances off or on.
You can also think of it as a AM radio and a thunderstorm.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Yes, the random frequencies that can be emanated by the arc within the switch (EMI) or spike on electrical circuit by turning appliances off or on.
You can also think of it as a AM radio and a thunderstorm.

In the first place, her stereo is getting signal from her cable service, not radio.

In the second place, she says this started after she had had a power outage and her ATS reconnected her to the grid.

In the third place, she has no knowledge of electrical matters and may be mistaken about when it started.
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
Just live with it. As I said it could be a filtering capacitor ahead of amp stage in stereo so it would not matter what input was selected (radio,TV,disc player). The amp within the stereo is simply amplifying a small spike/RFI/EMI on the circuit in which it is plugged into and you hear it coming from speakers.
When the ATS transfers back to utility power, the transition from generator power to utility could result in a spike on electrical system that may have damaged filtering capacitor. After all, it is abrupt to take generator power at one stage in the electrical cycle then within a split second re energize off utility at another point within a/c cycle. And concider what kind of inductive kickbacks are imposed from motor loads on your electric system.
Hope this helps explain it unless someone here has more electronics training than me that can elaborate.

Or it could be that the sound she now hears has always been there and now she has a new piece of electrical equipment she is being more observative to things around her and fixating on it. I'm sure sychiatrists probably have a name for it and it happens all the time.
 
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ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
She says that her generator guy came out and replaced "some switch" and now the noise is gone.
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
Would like to hear more on exactly what he replaced. Homeowners tend to get a simplistic explanation that sometimes doesn't accurately describe the technical babble.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Would like to hear more on exactly what he replaced. Homeowners tend to get a simplistic explanation that sometimes doesn't accurately describe the technical babble.

She is 87 years old and lives 300 miles away. I am not likely to get any more explanation than that. But she's happy with the result, whatever the guy did, so I'm happy, too.
 

iwire

Moderator
Staff member
Location
Massachusetts
She is 87 years old and lives 300 miles away. I am not likely to get any more explanation than that. But she's happy with the result, whatever the guy did, so I'm happy, too.

My mom is 86 and a maintainance guy just replaced her door bell. Now the front door just 'dings' and the back door 'ding dongs'. He told her it is not fixable and that he hooked it up just like the one he took down.

I have to swing by and make her happy, lucky she is only about 20 minutes drive from me.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
My mom is 86 and a maintainance guy just replaced her door bell. Now the front door just 'dings' and the back door 'ding dongs'. He told her it is not fixable and that he hooked it up just like the one he took down.

I have to swing by and make her happy, lucky she is only about 20 minutes drive from me.
What's the prob? It's not a bug, it's a feature; now she can tell by the sound which door has a visitor.
 

iwire

Moderator
Staff member
Location
Massachusetts
What's the prob? It's not a bug, it's a feature; now she can tell by the sound which door has a visitor.

It is a feature but it is backwards.


When you wire a door bell the the terminals are labeled front, rear and common.

The front door is intended to double chime, the rear door should single chime. The guy hooked it up backwards and could not figure it out.

Seeing as she is 86 and this is backwards from every home she had lived in it is a big deal to her. It's also a way to get me to stop by.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
It is a feature but it is backwards.


When you wire a door bell the the terminals are labeled front, rear and common.

The front door is intended to double chime, the rear door should single chime. The guy hooked it up backwards and could not figure it out.

Seeing as she is 86 and this is backwards from every home she had lived in it is a big deal to her. It's also a way to get me to stop by.
Are you bringing your laundry? :D
 
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