electricity issue at home

A

anbm

Senior Member
Location
TX
Occupation
Designer
This week, lights in my bedroom are suddenly dimmed and then off completely. I changed new bulbs, same thing happens,
this only occur in one bedroom, also the dryer does not receive enough electricity, not providing enough heat to dry the cloth,
everything else in house work fine....can this be issue at the power company transformer located at the street?
loosing wire connection maybe? should I call the power company?
 
A

AC\DC

Senior Member
Location
Florence,Oregon,Lane
Occupation
EC
call electrician, If only your bedroom lights are a problem, and nothing else is having a problem your dryer is another issue probably. if you lose a leg your other 240 volt circuits would be having a problem and you would have other 120 volt not working. You have a lose connection some were and your dryer just happened to have a problem or already had it and you never mentally linked it to anything till the lights went out.
 
synchro

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
anbm said:
This week, lights in my bedroom are suddenly dimmed and then off completely. I changed new bulbs, same thing happens,
this only occur in one bedroom ...
Click to expand...

If these bedroom lights are on a dimmer, perhaps there was a voltage surge that damaged the dimmer. And maybe the control circuitry in the dryer was also damaged.

I agree that meter measurements of the voltages need to be done.
If you have good voltages at a dimmer (assuming there is one in the bedroom), you might change it out for a mechanical switch to see if that makes it work consistently.
 
E

Elect117

Senior Member
Location
California
Occupation
Engineer E.E. P.E.
Maybe it is because I was practicing open neutral problems with a new Engineer in training, but it sounds like an open neutral.

An open neutral can look fine when the load is balanced but when something is switched off (or on) it can raise the voltage and current on the leg that has less load on it. It could be negatively impacting performance on the dryer. I think that might depend on how it is wired, but if it uses the exception for 250.140, and the "grounded conductor" (neutral) instead of the EGC, then that sounds like it could be why it is acting up on an open neutral.
 
ptonsparky

ptonsparky

Tom
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
Go back and study the open neutral symptoms.
Joe.B said:
Electrician needed to verify, but sounds like it could be the beginning of an open neutral.
Click to expand...
Elect117 said:
Maybe it is because I was practicing open neutral problems with a new Engineer in training, but it sounds like an open neutral.

An open neutral can look fine when the load is balanced but when something is switched off (or on) it can raise the voltage and current on the leg that has less load on it. It could be negatively impacting performance on the dryer. I think that might depend on how it is wired, but if it uses the exception for 250.140, and the "grounded conductor" (neutral) instead of the EGC, then that sounds like it could be why it is acting up on an open neutral.
Click to expand...
What happens to the respective L-N voltages?
 
Joe.B

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
ptonsparky said:
Go back and study the open neutral symptoms.


What happens to the respective L-N voltages?
Click to expand...
Based on the OP description of symptoms I said it "could be", and also I said an electrician is "needed to verify", specifically to see what's going on with things such as L-N voltages.
 
E

Elect117

Senior Member
Location
California
Occupation
Engineer E.E. P.E.
ptonsparky said:
Go back and study the open neutral symptoms.


What happens to the respective L-N voltages?
Click to expand...
They drop respectively. If L1 has more load, then the voltage drops and the current goes down. At the same time, L2 will have a higher voltage and a higher current.

Here is a video for your reference. He probably explains it better than I could.
 
Little Bill

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
They dryer would not lose heat if there was a neutral problem. In fact if might get hotter if the drum wasn't turning. The dryer is mostly 120V and the heating elements are the only 240V. So if one leg is lost, the heating elements wouldn't get as hot.

I can't say for certain that the dryer not heating and the lights dimming are the same problem, but if it was related, it would point more to a lost leg rather than a lost, or going bad, neutral. If a leg is lost, you might have lights that work, although dimly, then stop working. That is because the lost leg is receiving power through backfeed from one of the legs of a 240V load. Then when that load is turned off, the lights will go out.
OP may have had the dryer on when the lights were dim, then when the dryer was off the lights went out. Then he noticed the clothes were not dry. Classic lost leg symptom.

As far as other things working fine, it could be all the other lights are on the "good" leg, and you might not notice things that aren't used much that might be on the lost leg, so you wouldn't know unless you tried them.
 
R

retirede

Senior Member
Location
Illinois
Little Bill said:
They dryer would not lose heat if there was a neutral problem. In fact if might get hotter if the drum wasn't turning. The dryer is mostly 120V and the heating elements are the only 240V. So if one leg is lost, the heating elements wouldn't get as hot.

I can't say for certain that the dryer not heating and the lights dimming are the same problem, but if it was related, it would point more to a lost leg rather than a lost, or going bad, neutral. If a leg is lost, you might have lights that work, although dimly, then stop working. That is because the lost leg is receiving power through backfeed from one of the legs of a 240V load. Then when that load is turned off, the lights will go out.
OP may have had the dryer on when the lights were dim, then when the dryer was off the lights went out. Then he noticed the clothes were not dry. Classic lost leg symptom.

As far as other things working fine, it could be all the other lights are on the "good" leg, and you might not notice things that aren't used much that might be on the lost leg, so you wouldn't know unless you tried them.
Click to expand...

This is exactly was I was alluding to in post #8. I was just too lazy to spell everything out!


Sent from my iPad using Tapatalk
 
kwired

kwired

Electron manager
Location
NE Nebraska
Little Bill said:
They dryer would not lose heat if there was a neutral problem. In fact if might get hotter if the drum wasn't turning. The dryer is mostly 120V and the heating elements are the only 240V. So if one leg is lost, the heating elements wouldn't get as hot.

I can't say for certain that the dryer not heating and the lights dimming are the same problem, but if it was related, it would point more to a lost leg rather than a lost, or going bad, neutral. If a leg is lost, you might have lights that work, although dimly, then stop working. That is because the lost leg is receiving power through backfeed from one of the legs of a 240V load. Then when that load is turned off, the lights will go out.
OP may have had the dryer on when the lights were dim, then when the dryer was off the lights went out. Then he noticed the clothes were not dry. Classic lost leg symptom.

As far as other things working fine, it could be all the other lights are on the "good" leg, and you might not notice things that aren't used much that might be on the lost leg, so you wouldn't know unless you tried them.
Click to expand...
Most old school dryers anyway have a centrifugal switch on the motor that serves as an interlock for the heater circuit. If you lost the line the motor operates on you won't have heat either because of this switch.

If you lost the line the motor does not operate on, then the dryer will start because the motor and other controls are all on the other line and the neutral. How much heat you end up with is dependent on other loads in the house as the working line has the heater element in series with the non working line though it will still be dramatically reduced heating. Could possibly have say a water heater element between the two lines as well. Low loading conditions and especially with mostly LED lighting being common these days and you may be able to go a while and never know you lost the line. Eventually not having hot water, if that applies, might be your first indication of any trouble.

Lost neutral will result in one line being low and other line being high when loads are imbalanced and is normally noticed more easily when loading is rather low.
 
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A

anbm

Senior Member
Location
TX
Occupation
Designer
The mystery was discovered…

Power company folk came to the house and checked the outdoor xfmr voltage and wiring connection, no issue was found. The voltage reading data is acceptable…

1. I replaced both LED light bulbs inside the ceiling light has dimming issue, it works fine… If replacing only one bulb and keep the other existing bulb, the dimming issue still exists. Total cost $3

2. The electrican checked voltage, replaced the defective 240V/120V, 25A/2P GFCI breaker serving the dryer with a new 30A/2P GFCI breaker, the issue solved. New Eaton GFCI breaker costs $165. Labor $70.
 
4x4dually

4x4dually

Senior Member
Location
Stillwater, OK
Occupation
Electrical Engineer/ Ex-Electrician
Elect117 said:
They drop respectively. If L1 has more load, then the voltage drops and the current goes down. At the same time, L2 will have a higher voltage and a higher current.

Here is a video for your reference. He probably explains it better than I could.
Click to expand...
Wow. What a great video. Next time anyone asks me to explain an open neutral, they are getting this link first thing. Thanks for posting that.
 
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