We have a customer who is experiencing a periodic loud humming noise that last a couple of seconds in his electric room. He said he heard it was "inductive kick" and it will eventually cause a fault. Has anyone every heard of this term before and what can be done to correct this problem?
Inductive Kick?
- Thread starter jim popma
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Inductive Kick?
The property of ?induction? represents the ability of an electrical device to store energy in a magnetic field. It is usually discussed in the context of motors and generators, since their large coils of wire are highly ?inductive.? But even a straight wire has some measurable induction, and the induction of the finger nail clippers in your pocket is not zero.
The phrase ?inductive kick? is most often used in a sloppy, conversational manner, to describe any of the various behaviors that a motor or generator might exhibit, as it is being turned off or on. However, the ?kick? part of these behaviors lasts only a fraction of one second. Thus, the term does not really apply to the behavior of a large motor that takes several seconds to come up to speed.
Hillbilly is right: you are almost certainly looking at the starting cycle of a large motor. But the humming is probably not a normal condition. I am in the middle of a project in which an apartment building is experiencing the humming you describe. You can hear it in the electric room, whenever an elevator motor is started. In this instance, we believe that the humming is indicative of a potential failure in the making. Among the factors we are investigating are the ratings of the breaker, the size of the conductors, the tightness of the connections, and the capacity of the service transformer.
The property of ?induction? represents the ability of an electrical device to store energy in a magnetic field. It is usually discussed in the context of motors and generators, since their large coils of wire are highly ?inductive.? But even a straight wire has some measurable induction, and the induction of the finger nail clippers in your pocket is not zero.
The phrase ?inductive kick? is most often used in a sloppy, conversational manner, to describe any of the various behaviors that a motor or generator might exhibit, as it is being turned off or on. However, the ?kick? part of these behaviors lasts only a fraction of one second. Thus, the term does not really apply to the behavior of a large motor that takes several seconds to come up to speed.
Hillbilly is right: you are almost certainly looking at the starting cycle of a large motor. But the humming is probably not a normal condition. I am in the middle of a project in which an apartment building is experiencing the humming you describe. You can hear it in the electric room, whenever an elevator motor is started. In this instance, we believe that the humming is indicative of a potential failure in the making. Among the factors we are investigating are the ratings of the breaker, the size of the conductors, the tightness of the connections, and the capacity of the service transformer.
brian john
Senior Member
- Location
- Kilmarnock, Va
- Occupation
- Retired after 52 years in the trade.
Re: Inductive Kick?
We investigate numerous HUM’s in al type of electrical distribution equipment and rooms. The vast majority of these are loose or too tight covers. The noise is worse with higher loads. Try pressing on the covers of the affected equipment.
But by all means investigate, because just assuming it is a cover can be a big mistake
We investigate numerous HUM’s in al type of electrical distribution equipment and rooms. The vast majority of these are loose or too tight covers. The noise is worse with higher loads. Try pressing on the covers of the affected equipment.
But by all means investigate, because just assuming it is a cover can be a big mistake
scott thompson
Senior Member
- Location
- Anaheim, California
Re: Inductive Kick?
We've found a lot of those starting surge "Hums" that were Resonating the Branch Circuit's Conduit (shaking the Conductors inside, buzzing loose couplings, rattling loose strut straps, and such), and others rattling 4s / 5s box covers.
We also found (more than I expected to) buzzing inside of MCCB frames, and vibrating Bus Kits + Bolt-On Breaker terminations to Bus(es).
Forgot to mention the very loud buzzes due to plug-on bus type breakers having terminations that - in lack of a better term are: "Maybe 5 Starts From Flames".
Those are the connections which you bring Cole Slaw and Sauce to!
(AKA - Barbecued!)
Scott35
We've found a lot of those starting surge "Hums" that were Resonating the Branch Circuit's Conduit (shaking the Conductors inside, buzzing loose couplings, rattling loose strut straps, and such), and others rattling 4s / 5s box covers.
We also found (more than I expected to) buzzing inside of MCCB frames, and vibrating Bus Kits + Bolt-On Breaker terminations to Bus(es).
Forgot to mention the very loud buzzes due to plug-on bus type breakers having terminations that - in lack of a better term are: "Maybe 5 Starts From Flames".
Those are the connections which you bring Cole Slaw and Sauce to!
(AKA - Barbecued!)
Scott35
G
Guest
Guest
Re: Inductive Kick?
Harmonic vibration?
[ October 03, 2003, 03:22 PM: Message edited by: awwt ]
Harmonic vibration?
[ October 03, 2003, 03:22 PM: Message edited by: awwt ]
jrdsg
Senior Member
- Location
- Vancouver, Canada
Re: Inductive Kick?
is periodic loud humming different from whistling in the dark?
is periodic loud humming different from whistling in the dark?
brian john
Senior Member
- Location
- Kilmarnock, Va
- Occupation
- Retired after 52 years in the trade.
Re: Inductive Kick?
is periodic loud humming different from whistling in the dark?
jr: In both situations, it is only proff that you DON"T know the words.
is periodic loud humming different from whistling in the dark?
jr: In both situations, it is only proff that you DON"T know the words.
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