can a vacuum cleaner cause a surge????

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mike kiser

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i had someone i have a lot of respect for knowledge wise tell me that a vacuum cleaner can cause a surge within a home? i thought i had a good understanding of electricty but am somewhat befuddled by his comment.if a vacuum USES electrictry how will it send a SPIKE into the grid and if it can produce a spike i assumed that it would contain DIODES to block voltage returning to the grid. if anyone out there can answer this or point me in the right direction it would be a great help thanks.
 
mike kiser said:
i had someone i have a lot of respect for knowledge wise tell me that a vacuum cleaner can cause a surge within a home? i thought i had a good understanding of electricty but am somewhat befuddled by his comment.if a vacuum USES electrictry how will it send a SPIKE into the grid and if it can produce a spike i assumed that it would contain DIODES to block voltage returning to the grid. if anyone out there can answer this or point me in the right direction it would be a great help thanks.
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Tell us what you mean or better still what physically happens when the vacuum is turned on.
 
Quit sticking the hose on the cat !!!, and dimming the lights down...;)

I suppose some vac cleaner motors that are brushed motors could have alot of trash spikes due to normal brush arc's, Im sure that the current swings up and down a bit while sweeping, but Ive never heard of a serious issue, other than burning up cord and plugs and receptacles......:cool:

I see this is your 1st post, are you a electrician?
 
anything can cause a spike - your blender, air conditioner, a light switch. the question is - how big the spike is. suggest you google this and do some reading, I'm sure you will find lots of info. as to whether or not your spike is seen on the grid, well, maybe your air conditioner sags so a few neighbors can see it, but unless you have a really really big vacuum cleaner I doubt that it is noticable on the grid (you might want to google "grid" too)

this would be an example of a really large vacuum
312730main_image_1281_946-710.jpg
 
090301-1757 EST

A typical vacuum sweeper uses a universal motor. This consists of inductance, resistance, brushes, and a commutator. The brushes when the motor is rotating are fast operating switches. Suppose there are 20 segments on the commutator and the motor runs at 6000 RPM. 100 revolutions per second. Therefore you switch from one contact to the next 2000 times per second. Arcing occurs as the brushes slide on the commutator. You have RF (radio frequency) noise generated from the arcing, and there is probably some modulation at 2000 Hz and multiples thereof.

When the vacuum is turned on it will increase the load on the supply and the supply voltage at the vacuum will drop a little. When the vacuum is turned off the voltage will return to its level.

However, because you have current flowing in an inductor at the time of turn off there will be a transient voltage produced. Much of this voltage will occur across the power switch contacts. There maybe some very short transient rise in voltage on the supply wiring. Could be several thousand volts next to the switch and diminish as you move further from vacuum connection point.

These large transients are likely in the microsecond range.

None of this is very specific, just some generalizations. How does this relate to your question?

If I take an appropriate size capacitor and connect it to the supply I can probably produce some rather large voltage surge for a cycle or so. This would be done by selecting the capacitor to resonant at 60 Hz with the leakage inductance of the supply transformer. No such thing is in the vacuum sweeper.

.
 
gar said:
090301-1757 EST

A typical vacuum sweeper uses a universal motor. This consists of inductance, resistance, brushes, and a commutator. The brushes when the motor is rotating are fast operating switches. Suppose there are 20 segments on the commutator and the motor runs at 6000 RPM. 100 revolutions per second. Therefore you switch from one contact to the next 2000 times per second. Arcing occurs as the brushes slide on the commutator. You have RF (radio frequency) noise generated from the arcing, and there is probably some modulation at 2000 Hz and multiples thereof.

When the vacuum is turned on it will increase the load on the supply and the supply voltage at the vacuum will drop a little. When the vacuum is turned off the voltage will return to its level.

However, because you have current flowing in an inductor at the time of turn off there will be a transient voltage produced. Much of this voltage will occur across the power switch contacts. There maybe some very short transient rise in voltage on the supply wiring. Could be several thousand volts next to the switch and diminish as you move further from vacuum connection point.

These large transients are likely in the microsecond range.

None of this is very specific, just some generalizations. How does this relate to your question?

If I take an appropriate size capacitor and connect it to the supply I can probably produce some rather large voltage surge for a cycle or so. This would be done by selecting the capacitor to resonant at 60 Hz with the leakage inductance of the supply transformer. No such thing is in the vacuum sweeper.

.
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Im impressed....!!! SaaLute a knowledable feller..... can't they just tie all of those commutator segments together and quit that arcing?. sounds logical to me, then you wouldn't have to undercut...................:D:D
 
actually the topic came up as he was trying to justify installing a surge protector in a residence.he informed the people in the room that any major appliance could cause a spike i feel that a sag is more probable rather than a spike, and that surge protectors are meant to protect the residence from the grid and not appliances within the residence.unfortunately i was unable to obtain any solid info by googling this topic and hope that someone here can break it down shotgun style for me thanks... and yes im an electrician
 
090302-1427 EST

mike kiser:

You can get transient voltages from loads within your home from inductive loads when they are switched off. These are short duration, much shorter than a half cycle. A surge protector, MOV type device or equivalent, would help here. These do not clip heavily until way above peak line voltage.

For study search for MOV (metal oxide varistor), back to back Zener diodes, and Thyrector (I think this was a GE trademark).
http://so-much-stuff.com/pdp8/pdf/6rs20sp.pdf

A surge (voltage increase) is a type of transient of great energy that lasts for a moderately long time. Maybe a half cycle or much longer. No real source in a home for this type of transient. Also standard MOV devices are unlikely to provide any protection for this type of transient.

I have a lot of 8' Slimline fixtures. These are good transient generators. However, on most of these I have a noise filter. This is a low pass L-C filter. These will greatly reduce transient peaks.

If you apply a high voltage impulse to the input of a low pass filter the energy of the pulse is spread out over a much longer time at the output and therefore the peak output amplitude is greatly reduced.

In WWII there was a high failure rate of vacuum tubes on board ship. Shock measurements at gun mounts produced figures like 1000 G. So ruggedized tubes were developed to withstand these shock levels and the measured durations. When put on board ship these ruggedized tubes were essentially no better than the standard tubes. The design criteria was wrong. The very high short duration shock impulse at the gun mount was reduced in amplitude but stretched in duration because of the low pass characteristic of the ship hull. So at the equipment location a much different shock was imparted to the tube than for what the tube was designed.

.
 
nakulak said:
anything can cause a spike - your blender, air conditioner, a light switch. the question is - how big the spike is. suggest you google this and do some reading, I'm sure you will find lots of info. as to whether or not your spike is seen on the grid, well, maybe your air conditioner sags so a few neighbors can see it, but unless you have a really really big vacuum cleaner I doubt that it is noticable on the grid (you might want to google "grid" too)

this would be an example of a really large vacuum
312730main_image_1281_946-710.jpg
Click to expand...

Is that the vaccum from the movie "Spaceballs" that sucks all the air out of the planet?:grin:

My 2 cents on the discussion: I have never seen any direct correlation between any voltage transients coming from devices in the home switching on or off, other equipment in the house getting damaged. Surge protection is generally a good idea with respect to plug in TVSS, and possibly one at the main, but I don't think it is necessary due to the appliances switching on/off.

Many people outside of our industry often associate a surge with what was actually a voltage sag. A vaccum cleaner in a home...sounds like this might be the case and a surge protector is not really necessary for this reason.
 
can a vacuum cleaner cause a surge

can a vacuum cleaner cause a surge

What I like best about this post/thread was that the 'surge protector ' factor was not mentioned initially--it felt like a puzzle--And here I thought it was about to be another reference to motor induced surges causing nuisance afci tripping issues.
My Dad wrote books on electric theory years ago--same 'puzzle problem-theory-possible answers-correct answer' method and I can see him shakin' his head at me up there.
What a flash back-well...,I guess now i should just go to the panel now for a jolt.
 
gar said:
090302-1427 EST

mike kiser:

In WWII there was a high failure rate of vacuum tubes on board ship. Shock measurements at gun mounts produced figures like 1000 G. So ruggedized tubes were developed to withstand these shock levels and the measured durations. When put on board ship these ruggedized tubes were essentially no better than the standard tubes. The design criteria was wrong. The very high short duration shock impulse at the gun mount was reduced in amplitude but stretched in duration because of the low pass characteristic of the ship hull. So at the equipment location a much different shock was imparted to the tube than for what the tube was designed.

.
Click to expand...
gar:

During my Navy days, '62-'65 on board ship, some transceivers were shock mounted. When they were installing them, I remember the riggers would use the shock mounts to bounce them over the hatch entrance into the radio room and to their locations.
 
I've seen vacuums cause a surge of sorts on multi-wire circuits. Switch it on in one room, the lights get brighter across the hall!

Same sort of thing, it would seem.:D
 
090328-0849 EST

Bill:

I assume that was still tube type equipment.

Every so often when loading ammunition onto the ship a 16" shell would get dropped, the decks are wood, and you would hear a thud. When these were fired you would hear a big boom, and then a rush of air. Any shock was something I did not particularly detect. Obviously the equipment would because it was directly connected to the ship structure. 5" guns produced a very sharp crack and not the noticeable wind. The acoustic effect was much worse from the 5" and I could not hear in one ear for several days following one night when I was within 20 feet when the gun was fired. This caused permanent loss of high frequency capability in that ear.


kbsparky:

The cause of the surge from the vacuum was a high resistance neutral common to the two phases, and the opposite phase saw the surge. This surge would remain as long as the vacuum was on, and would be somewhat greater on initial turn on of the vacuum.

.
 
Spikes, surges, and swells all describe different types of overvoltage events. In the world of power quality knowing what the problem is every important as each condition requires a different type of protective devices.
 
gar said:
090328-0849 EST

Bill:

I assume that was still tube type equipment.

Every so often when loading ammunition onto the ship a 16" shell would get dropped, the decks are wood, and you would hear a thud. When these were fired you would hear a big boom, and then a rush of air. Any shock was something I did not particularly detect. Obviously the equipment would because it was directly connected to the ship structure. 5" guns produced a very sharp crack and not the noticeable wind. The acoustic effect was much worse from the 5" and I could not hear in one ear for several days following one night when I was within 20 feet when the gun was fired. This caused permanent loss of high frequency capability in that ear.
.
Click to expand...
gar:

They were of the sub-miniture tube type but the PA had two large ceramic tubes. It was a communication ship with only a single 5", two twin 40s and seldom used.

The story we heard, how true, I don't know was that the propeller shaft isn't just turned off after a voyage, it's done slowly over time to allowed it to cool down slowly. Even after days at a pier, it's still turning very slowly. Because of a emergency repair, it had to be shut down and warped. In rough seas, the prop comes out of the water causing the whole ship to shake. You could see those units moving on their shock mounts.
 
mthead said:
What I like best about this post/thread was that the 'surge protector ' factor was not mentioned initially--it felt like a puzzle--And here I thought it was about to be another reference to motor induced surges causing nuisance afci tripping issues.
My Dad wrote books on electric theory years ago--same 'puzzle problem-theory-possible answers-correct answer' method and I can see him shakin' his head at me up there.
What a flash back-well...,I guess now i should just go to the panel now for a jolt.
Click to expand...

Can you post links to these or are they out of publication.

Thanks
 
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