Humming
- Thread starter guschash
- Start date
- Status
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Pulsed load (like an SCR dimmer) causing the magnetic trip coil to vibrate?
I doesn't know the words?
readydave8
re member
- Location
- Clarkesville, Georgia
- Occupation
- electrician
In several cases I thought a breaker was humming only to find that it powered nearby transformer or ballast.
- Location
- Simi Valley, CA
No Daja7 had the right answer.
K8MHZ
Senior Member
- Occupation
- Electrician
Bees?
Not so much in jest, either. Especially if the meter can is adjacent to the panel.
mek421
Member
- Location
- Upstate NY, USA
I hope this does not come from personal experience.
Drake Pallister
Member
- Location
- Old Bridge, NJ
Humming Breaker
Humming Breaker
Branch circuit breaker supplying mainly or only lighting. Hmm. Considering the suggestions already been made... Does it only hum while load is applied? (I've had humming 200 A 3ph Square-D QO Main in a 40 space, even after all shutting off all breakers below, and was barely even acceptably warm to the feel -- next to an identical panel that was totally silent) If convenient narrow down to the problem being the breaker or the load sending back undesirable eddies by: 1) swapping the breaker 2) swapping the load to another breaker of same size in the same panel. 3) if the load causes a different breaker to hum, then the breaker isn't the issue, it is likely from the load. 4) load-test that breaker with a pure resistive load directly to the panel's neutral , will give an idea if it's an inductive circuit load issue. Even if a it's a brand new breaker, and you narrow the problem down to the breaker being the culprit, I have learned that "new" just means that you recently paid money for it, not that it couldn't be defective. If it's the circuit causing the hum, and if you can't physically see all the load, such as in an open warehouse, maybe there's more than meets the eye happening. Not knowing if it's a single or polyphase panel, something else could have been connected to the branch circuit by someone else at some period in the past, and perhaps there's a sharing of phases happening. I'd be curious if there was any substantial (more than stray) coming back from a different phase on that outbound circuit when the conductor is disconnected from the breaker.
Internet-- It's just diagnostic methodology suggestions unless physically onsite, right?
Regards,
Drake,
NJ
Humming Breaker
Branch circuit breaker supplying mainly or only lighting. Hmm. Considering the suggestions already been made... Does it only hum while load is applied? (I've had humming 200 A 3ph Square-D QO Main in a 40 space, even after all shutting off all breakers below, and was barely even acceptably warm to the feel -- next to an identical panel that was totally silent) If convenient narrow down to the problem being the breaker or the load sending back undesirable eddies by: 1) swapping the breaker 2) swapping the load to another breaker of same size in the same panel. 3) if the load causes a different breaker to hum, then the breaker isn't the issue, it is likely from the load. 4) load-test that breaker with a pure resistive load directly to the panel's neutral , will give an idea if it's an inductive circuit load issue. Even if a it's a brand new breaker, and you narrow the problem down to the breaker being the culprit, I have learned that "new" just means that you recently paid money for it, not that it couldn't be defective. If it's the circuit causing the hum, and if you can't physically see all the load, such as in an open warehouse, maybe there's more than meets the eye happening. Not knowing if it's a single or polyphase panel, something else could have been connected to the branch circuit by someone else at some period in the past, and perhaps there's a sharing of phases happening. I'd be curious if there was any substantial (more than stray) coming back from a different phase on that outbound circuit when the conductor is disconnected from the breaker.
Internet-- It's just diagnostic methodology suggestions unless physically onsite, right?
Regards,
Drake,
NJ
K8MHZ
Senior Member
- Occupation
- Electrician
Actually, I read something similar on a thread in one of the forums here, and it is very common to find bee's nests in old meter sockets. At least in my area.
I have been on large commercial jobs where the supervision was not what it should have been
and the Electrician that installed the Sub panel has taken the feeder neutral feed through a different
conduit from the ungrounded feeder conductors.
And some times its just sounds like it is one of the breakers humming.This makes the metal
Enclosure of the panel act like a transformer lamination it over heats and hums.The panel neutral has to have a heavy load on it to do this.
You would be very suprised to know how many Good Electricians and inspectors alike don't
realize how important it is to group all conductor Eq. grd,neutral and ungrounded conductors
into one conduit for feeders.
Ronald
- Status