electrical ghosts

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Re: electrical ghosts

What are the voltages of the other phases when a load is applied?
Has there been any noticeable lights getting brighter/dimmer?
Do you have a DVM/Amp-Probe with peek reading and hold feature?
The only way to diagnose a problem like this is having the proper equipment and the know how to operate it. Most utilities will install a special meter that monitors power quality and will give you a readout after 48hrs which might give you some incite as to which side of the meter it might be coming from but don't expect a miracle, as many times it can be from branch circuit wiring or a problem in the panel even a loose buss bar. Without PQ monitoring equipment it's hard to see whats really happing. Something is just not making any sense.
With your Amp-Probe try to see what the start up current is on the saw. It can't be the 10 amps you posted? What are your phase to neutral voltages? what are your phase to phase voltages? unloaded and after loaded.
Try to un-balance the panel by only turning on single pole breakers to a known resistance load on one phase of the panel only, then measure the voltage to see if it goes low while the other phase go high.
If it does then it is a bad neutral connection. To see a intermittent loose connection a true RMS meter will not show it, but a peek reading meter will.
It's to fast sometimes for the dampened meter (RMS) to show it. I've had this problem a few times and the POCO would only use the RMS setting on their meter, which would not show the fast fluctuations of the loose connection.
 
Re: electrical ghosts

Mdshunk , absoulutly the grounding means is just as important as the incoming ungrounded conductors
For instance if the service is bonded at the first
service dissconnecting means and then again through-out the building ,you have a corrupted grnd. path and the breakers will not function properly.

It is very important that neutral current and fault current follow a direct path back to the incoming neutral
 
Re: electrical ghosts

Originally posted by honeyfarmer:
For instance if the service is bonded at the first
service disconnecting means and then again through-out the building ,you have a corrupted grnd. path and the breakers will not function properly.
Click to expand...
The breakers will work just fine with multiple bonds. There will be current flowing on EGCs that will be undesirable.
 
Re: electrical ghosts

I respectfully dissagree ,and it certainly would not hurt to research this because as you say that undesirable path is agaist code and is potentially dangerous to life and safety and could cure the problem :eek:
 
Re: electrical ghosts

Originally posted by honeyfarmer:
I respectfully dissagree ,and it certainly would not hurt to research this because as you say that undesirable path is agaist code and is potentially dangerous to life and safety and could cure the problem :)
Click to expand...
 
Re: electrical ghosts

the power company is exempt from the NEC ,yes ?
I have no idea how there ocpd s work or what they are rated at ,but I would surmise they are mainly concerned about fault current .

However our ocpd devices are much more sensitive than theres for life safety reasons ,yes ?

this problem has been troubleshooted at the panel in the space already .grounding problems can wreak all sorts of havoc
 
Re: electrical ghosts

The only thing multiple bonds will do to OCP operation is to help it.

More bonds results in less total resistance back to the source.

Of course multiple bonds are not wanted for other reasons.
 
Re: electrical ghosts

The only thing multiple bonds will do to OCP operation is to help it.

I disagree ,we want a clean path back to momma neautral ,the lastest info out ,research iso grounds , is saying that almost all backflo current is going back to the Utility co. neutral and dissapating on the way and not going into the grnd -mother earth

Multiple bonds will cause current flo going everywhere and is highly undesireable and if you ever come across it should be cleaned up .
this will cause all sorts of problems with electronic equipment ie. computer rooms and server rooms
 
Re: electrical ghosts

Originally posted by honeyfarmer:
I disagree ,we want a clean path back to momma neutral ,the lastest info out ,research iso grounds , is saying that almost all backflo current is going back to the Utility co. neutral and dissapating on the way and not going into the grnd -mother earth
Click to expand...
Honey isolated grounds are hardly the latest thing. :D

You mixing two separate issues, OCP operation which is aided by multiple bonds and unwanted electrical current flowing on EGCs which can be caused by multiple bonds.

During a ground fault the only direction current will flow is back to the source. The more paths (less impedance) back to the source the better for OCP operation.
 
Re: electrical ghosts

I had sort of the same thing happen to me. I had a chop saw which tripped the breaker but only when it was plugged into a GFCI Recpticle. Never tripped the recepticle though. I found that the recepticle was breaking down under the starting load of the saw and making the phase go to ground and kicking the breaker. The way I fixed this was to install a single recepticle especially for the saw which wasnt protected by a GFCI. I dont know if this is the case with you but if your recepticles you are plugged into are a GFCI or GFCI protected recepticle by feeding through a GFCI recepticle, this may be what is happening with you.
 
Re: electrical ghosts

although there is no mention of GFI in the post ,
And still contend that a bad grnd path can cause breakers to not function properly .I will research this to give you a more informed answer
 
Re: electrical ghosts

Every electrical circuit is protected by a circuit breaker. The purpose of the circuit breaker is to prevent the building wiring from overheating as a result of excessive user loads being plugged in. However, in the 3-wire system, the circuit breaker provides another critical safety function. If a hot wire or circuit were to become accidentally connected to an exposed metal part on a piece of equipment, then a shock hazard would exist. However, if the exposed parts are connected to the grounding wire, then the hot wire becomes connected to the grounding wire. This would not cause anything unusual to happen except for the fact that the second power wire, the neutral wire, is also connected to the grounding wire at the circuit breaker panel. Therefore, for this safety hazard the grounding wire essentially becomes connected as a load. The low resistance of the grounding wire causes it to draw a very large amount of current when it becomes inadvertently connected as a load, which in turn causes the circuit breaker feeding the hot wire to trip. Therefore, the 3-wire system operates in a manner which transforms a safety hazard into an over current condition, causing the safety hazard to be automatically cleared by the circuit breaker. The circuit breaker is used as both an over current protector and a shock hazard protector.

this what happens with multiple bonds
 
Re: electrical ghosts

Grounding is probably the source of the greatest confusion in the understanding of electrical power distribution. The National Electric Code? does little to clear this fog of misunderstanding.
Purposes of Grounding
"To limit voltages due to lightning, line surges or unintentional contact with higher voltage lines..."

These three sources of dangerous overvoltage are provided with an alternative path around the electrical system of your home or workplace by intentionally connecting the system to the earth.

This is a difficult concept. There are many sources of electricity. Every transformer can be considered a separate source. If there were not a common reference point for all these voltage sources it would be extremely difficult to calculate their relationships to each other.

The earth of course is the most omnipresent conductive surface, and so it was adopted in the very beginnings of the National Electric Code? as a nearly universal standard for all electric systems(there are a few exceptions where ungrounded systems are permitted).

"To provide a path in order to facilitate the operation of overcurrent devices..."

From a day to day point of view this last purpose of grounding is the most important one to understand.
 
Re: electrical ghosts

The rule of parallel resistance is, the total resistance will be lower than the lowest resistor in the parallel paths.

Low resistance is just what we are looking for to facilitate the opening of the over current device.

A bad grounding path is no good as the resistance will be high and the over current device will not operate.

Current = voltage divided by resistance

Example 1; 120 volts divided by 10 ohms of resistance equals 12 amps. This would not be enough to open a 15 amp over current device.

Example 2; 120 volts divided by 0.1 ohm of resistance equals 1200 amps of current and the 15 amp over current device will open.
__________________
Mike
North Carolina
 
Re: electrical ghosts

Mike make your posts as long as you want the fact remains that more paths back to the source results in lower overall resistance.

Lower total resistance results in quicker operation of the OCP.

You do understand that for a OCP to operate there must be a low resistance connection back to the source and the source is not 'mother earth'.
 
Re: electrical ghosts

sorry ,Mike is the name of the guy who wrote the peice ,otherwise known as JWELECTRIC

I go by Bill ,of Local 26 IBEW,Truland systems

the posts are pasted from other sites and in no way do I think long makes correct ,however multiple paths/bonds between nuetral +grnd -see nuetral fault -are not a quicker path but a corrupted path which current does not flow back directly to source but go in loop runs and every where but back to the source directly

{Moderator's Note: Edited to remove inappropriate language.}

[ November 07, 2005, 11:15 AM: Message edited by: charlie b ]
 
Re: electrical ghosts

If you are going to cut and paste from elsewhere you should make it known that you are quoting from someone.

Click on the
ubb_quote.gif
button below the reply screen and place your text between the QUOTES.

Roger
 
Re: electrical ghosts

Mike
You have mentioned how important understanding the concept of grounding is, I agree. I do not agree on your take of grounding, and I think you need to do more than research. Mike Holt has a good book discussing grounding and bonding, written just for electricians. I have an extra copy, and would be willing to send it to you for no charge. After reading it, I believe you will see where you are misunderstanding some of it. PM me with your address, and I will mail it tomorrow.
 
Re: electrical ghosts

I suggest you take up Pierre's generous offer. :cool:

Bob

{Moderator's Note: Edited because this thread referred to another comment that has since been deleted. I just didn't want anyone to be confused.}

[ November 07, 2005, 11:17 AM: Message edited by: charlie b ]
 
Re: electrical ghosts

Originally posted by jwelectric, reposted by honeyfarmer:
The rule of parallel resistance is, the total resistance will be lower than the lowest resistor in the parallel paths.
Click to expand...
Bill, just look at this one statement. Focus on it, it is the key.

Parallel resistance provides a path with a resistance lower than the lowest solo path.

Less resistance to current allows more current to pass, opening a breaker faster.

Definutely talk to Pierre, you will not regret it one bit. The NEC is not talking about "grounding" when it uses the term "Equipment Grounding Conductor", there's no shame in getting confused - it's poorly written and prone to misunderstanding. Mike Holt's book is an excellent place to gain understanding on this difficult issue. :)
 
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