Earl Krueger on mon 17 dec 07
Most of the time when I read well recognized
pottery experts give "expert" advice on subjects
they may know a little about but do not have a
deep understanding of I usually chuckle a little
and then move on to the next topic. But the
recent advice to remove the GFCI device from
the circuit you use to power your wheel is not
only bad advice, it is dangerous advice which
I can not let slide without comment.
To the person whose wheel trips their GFCI device
I have a Shimpo VL Whisper and it runs fine on
a GFCI protected circuit. In fact, I will not run
it on a circuit that is not GFCI protected as I value
my life a little more than the few dollars it takes
to install a GFCI device. I will explain how GFCI
works and it should become apparent why I feel
the way I do.
In the USA, modern day 110-120V electrical circuits
in your home or studio consist of 3 wires. One is the
"Hot" wire which can be thought of as bringing the
electricity to the outlet, one is the "Neutral" wire which
is used to complete the electrical circuit when the power
switch is "ON" and one is the "Ground" wire which
is there mostly for safety reasons.
Many people get confused about the difference
between the Neutral and Ground wires, especially
since if you follow them back to the power panel you
will find that they are tied together by a bus bar and
are therefore at the same electrical potential at that
point at all times. The real difference between the
two occurs inside the device you plug into the outlet;
your wheel for example.
Inside the wheel's electronics package the Hot and
Neutral wires are connected so that when the power
switch is in the "ON" position they, along with the
electronics, form a complete electrical circuit. Current
flows through both wires. Look closely and you will
see that both Hot and Neutral are insulated from all
metal parts that you might touch in order to protect
you from any electrical current.
But what happens if that insulation should fail or a
stray wire touch against the metal case. Then the
metal case, even the wheel head, could become
Hot and if you were touching that part and something
else that provided a good return path for the electricity
you would definetly not have a good day. This is
where the Ground wire comes into play.
The Ground wire is connected to the metal parts of
your wheel that do not form a part of the normal
electrical circuit. If for some reason, as given above,
the metal case should become Hot then the Ground
wire will provide a low resistance return path to the
power panel and since there would most likely be an
excessive amount of current flowing the circuit
breaker would trip cutting off the electricity to your
wheel. So we're protected, right? Well, not really !
You see, it may take a second or more for the
circuit breaker to trip. In that time the voltage
at your wheel, and in you, will reach maximum
potential or 170 volts 120 times. Your internal
circuitry, heart, brain, etc. may not be able to
handle that much disruption without dire
consequences. This is where the GFCI device
comes into play.
When a circuit is operating normally the electrical
current flowing through the Hot wire and the Neutral
wire have to be the same. When there is a "Short"
circuit some of the current flows through a different
path than the Neutral wire. The GFCI device
monitors the current flow through the Hot and Neutral
wires and if it detects a difference it will turn off
electricity to the Hot wire. And it does this quick.
So quick, in fact, that the device being protected,
and you, can experience the electricity reaching it's
maximum potential a maximum of one time. This
may be enough for you to feel the shock but it's not
normally enough to cause you severe problems, like
dying.
The electrical building codes in effect today require
GFCI protection in locations where it is likely that
potential alternate ground paths exists, such as
around plumbing fixtures, outdoor locations, garages
and such and where water is likely to be around to
facilitate the flow of electricity.
I consider working on a wheel with both hands wet
and touching metal parts which may become Hot
enough of a risk that I won't use my wheel unless
it is plugged into a known good GFCI protected
circuit. I believe that a pottery wheel fits with the
spirit of the electrical codes definitions of high risk
situations.
And, to be technically correct, it is Ground Fault Circuit
Interrupter (GFCI) not Ground Fault Interrupter (GFI)
since the device interrupts power to the circuit
that is experiencing the ground fault; it does not
interupt the ground fault itself.
Earl Krueger
Veneta, Oregon, usa
Alisha Clarke on tue 18 dec 07
I agree with Earl that GFCI protection is a good safeguard, but what do you
do when you have a device that constantly trips the circuit. I finished the
construction of a new studio attached to my garage this summer ( you can
see pictures of it at http://www.flickr.com/gp/65564173@N00/QKFG29 ). All of
the 110 recepticles are protected with GFCI. However, I found that my new
Peter Pugger VPM-9 trips the GFCI. The only way I could get it to work is to
connect it to a non-GFCI circuit. Right now I'm running an extension cord
from the garage, but I was planning to move the GFCI receptacle on one of
the lines to the second box so I have a non-GFCI outlet in the studio I
could use for the VPM-9.
Should a heavy drawing item like a pugmill still be able to work on GFCI? Is
there an alternative GFCI receptacle that would work for it, or does this
suggest a flaw in the pugmill?
Leesh
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
Pottery by Leesh: www.alishaclarke.com
Pottery Basics: www.potterybasics.com
On Dec 18, 2007 2:17 AM, Earl Krueger wrote:
> Most of the time when I read well recognized
> pottery experts give "expert" advice on subjects
> they may know a little about but do not have a
> deep understanding of I usually chuckle a little
> and then move on to the next topic. But the
> recent advice to remove the GFCI device from
> the circuit you use to power your wheel is not
> only bad advice, it is dangerous advice which
> I can not let slide without comment.
>
> To the person whose wheel trips their GFCI device
> I have a Shimpo VL Whisper and it runs fine on
> a GFCI protected circuit. In fact, I will not run
> it on a circuit that is not GFCI protected as I value
> my life a little more than the few dollars it takes
> to install a GFCI device. I will explain how GFCI
> works and it should become apparent why I feel
> the way I do.
>
> In the USA, modern day 110-120V electrical circuits
> in your home or studio consist of 3 wires. One is the
> "Hot" wire which can be thought of as bringing the
> electricity to the outlet, one is the "Neutral" wire which
> is used to complete the electrical circuit when the power
> switch is "ON" and one is the "Ground" wire which
> is there mostly for safety reasons.
>
> Many people get confused about the difference
> between the Neutral and Ground wires, especially
> since if you follow them back to the power panel you
> will find that they are tied together by a bus bar and
> are therefore at the same electrical potential at that
> point at all times. The real difference between the
> two occurs inside the device you plug into the outlet;
> your wheel for example.
>
> Inside the wheel's electronics package the Hot and
> Neutral wires are connected so that when the power
> switch is in the "ON" position they, along with the
> electronics, form a complete electrical circuit. Current
> flows through both wires. Look closely and you will
> see that both Hot and Neutral are insulated from all
> metal parts that you might touch in order to protect
> you from any electrical current.
>
> But what happens if that insulation should fail or a
> stray wire touch against the metal case. Then the
> metal case, even the wheel head, could become
> Hot and if you were touching that part and something
> else that provided a good return path for the electricity
> you would definetly not have a good day. This is
> where the Ground wire comes into play.
>
> The Ground wire is connected to the metal parts of
> your wheel that do not form a part of the normal
> electrical circuit. If for some reason, as given above,
> the metal case should become Hot then the Ground
> wire will provide a low resistance return path to the
> power panel and since there would most likely be an
> excessive amount of current flowing the circuit
> breaker would trip cutting off the electricity to your
> wheel. So we're protected, right? Well, not really !
>
> You see, it may take a second or more for the
> circuit breaker to trip. In that time the voltage
> at your wheel, and in you, will reach maximum
> potential or 170 volts 120 times. Your internal
> circuitry, heart, brain, etc. may not be able to
> handle that much disruption without dire
> consequences. This is where the GFCI device
> comes into play.
>
> When a circuit is operating normally the electrical
> current flowing through the Hot wire and the Neutral
> wire have to be the same. When there is a "Short"
> circuit some of the current flows through a different
> path than the Neutral wire. The GFCI device
> monitors the current flow through the Hot and Neutral
> wires and if it detects a difference it will turn off
> electricity to the Hot wire. And it does this quick.
> So quick, in fact, that the device being protected,
> and you, can experience the electricity reaching it's
> maximum potential a maximum of one time. This
> may be enough for you to feel the shock but it's not
> normally enough to cause you severe problems, like
> dying.
>
> The electrical building codes in effect today require
> GFCI protection in locations where it is likely that
> potential alternate ground paths exists, such as
> around plumbing fixtures, outdoor locations, garages
> and such and where water is likely to be around to
> facilitate the flow of electricity.
>
> I consider working on a wheel with both hands wet
> and touching metal parts which may become Hot
> enough of a risk that I won't use my wheel unless
> it is plugged into a known good GFCI protected
> circuit. I believe that a pottery wheel fits with the
> spirit of the electrical codes definitions of high risk
> situations.
>
> And, to be technically correct, it is Ground Fault Circuit
> Interrupter (GFCI) not Ground Fault Interrupter (GFI)
> since the device interrupts power to the circuit
> that is experiencing the ground fault; it does not
> interupt the ground fault itself.
>
> Earl Krueger
> Veneta, Oregon, usa
>
>
> ______________________________________________________________________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, or change your
> subscription settings here: http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
--
Larry Kruzan on tue 18 dec 07
Hi Leesh,
The Peter Pugger VPM-9 specs call for a current draw of 8 amps for the motor
and 3 amps for the vacuum pump. On startup any electric motor instantly
draws up to three times the running current for the first few milliseconds.
So your VPM-9 could be drawing as much as 25 amps during this initial
start-up spike. To a GFI this spike would "look" like a short circuit and
cause the safety to trip. Remember the job of a GFI is to protect us.
If you are using the normal easy to find GFI outlet receptacle it may only
be rated for 15 amps - not enough.
I have my VPM-60 on a dedicated circuit with a 40 amp GFI protecting it (and
me). I designed my studio to be cleaned up with a hose so every outlet is
protected with a GFI and sized for the load. There are four wheels on one
15 amp circuit and even with students at all four I've never had a problem,
but if I plug the studio vac into that circuit it will trip every time -
have to use a 20 amp circuit for that unit.
Larry Kruzan
Lost Creek Pottery
www.lostcreekpottery.com
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Alisha Clarke
Sent: Tuesday, December 18, 2007 8:32 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: [CLAYART] GFCI and Pottery wheels; its your life at stake
I agree with Earl that GFCI protection is a good safeguard, but what do you
do when you have a device that constantly trips the circuit. I finished the
construction of a new studio attached to my garage this summer ( you can
see pictures of it at http://www.flickr.com/gp/65564173@N00/QKFG29 ). All of
the 110 recepticles are protected with GFCI. However, I found that my new
Peter Pugger VPM-9 trips the GFCI. The only way I could get it to work is to
connect it to a non-GFCI circuit. Right now I'm running an extension cord
from the garage, but I was planning to move the GFCI receptacle on one of
the lines to the second box so I have a non-GFCI outlet in the studio I
could use for the VPM-9.
Should a heavy drawing item like a pugmill still be able to work on GFCI? Is
there an alternative GFCI receptacle that would work for it, or does this
suggest a flaw in the pugmill?
Leesh
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
Pottery by Leesh: www.alishaclarke.com
Pottery Basics: www.potterybasics.com
On Dec 18, 2007 2:17 AM, Earl Krueger wrote:
> Most of the time when I read well recognized
> pottery experts give "expert" advice on subjects
> they may know a little about but do not have a
> deep understanding of I usually chuckle a little
> and then move on to the next topic. But the
> recent advice to remove the GFCI device from
> the circuit you use to power your wheel is not
> only bad advice, it is dangerous advice which
> I can not let slide without comment.
>
> To the person whose wheel trips their GFCI device
> I have a Shimpo VL Whisper and it runs fine on
> a GFCI protected circuit. In fact, I will not run
> it on a circuit that is not GFCI protected as I value
> my life a little more than the few dollars it takes
> to install a GFCI device. I will explain how GFCI
> works and it should become apparent why I feel
> the way I do.
>
> In the USA, modern day 110-120V electrical circuits
> in your home or studio consist of 3 wires. One is the
> "Hot" wire which can be thought of as bringing the
> electricity to the outlet, one is the "Neutral" wire which
> is used to complete the electrical circuit when the power
> switch is "ON" and one is the "Ground" wire which
> is there mostly for safety reasons.
>
> Many people get confused about the difference
> between the Neutral and Ground wires, especially
> since if you follow them back to the power panel you
> will find that they are tied together by a bus bar and
> are therefore at the same electrical potential at that
> point at all times. The real difference between the
> two occurs inside the device you plug into the outlet;
> your wheel for example.
>
> Inside the wheel's electronics package the Hot and
> Neutral wires are connected so that when the power
> switch is in the "ON" position they, along with the
> electronics, form a complete electrical circuit. Current
> flows through both wires. Look closely and you will
> see that both Hot and Neutral are insulated from all
> metal parts that you might touch in order to protect
> you from any electrical current.
>
> But what happens if that insulation should fail or a
> stray wire touch against the metal case. Then the
> metal case, even the wheel head, could become
> Hot and if you were touching that part and something
> else that provided a good return path for the electricity
> you would definetly not have a good day. This is
> where the Ground wire comes into play.
>
> The Ground wire is connected to the metal parts of
> your wheel that do not form a part of the normal
> electrical circuit. If for some reason, as given above,
> the metal case should become Hot then the Ground
> wire will provide a low resistance return path to the
> power panel and since there would most likely be an
> excessive amount of current flowing the circuit
> breaker would trip cutting off the electricity to your
> wheel. So we're protected, right? Well, not really !
>
> You see, it may take a second or more for the
> circuit breaker to trip. In that time the voltage
> at your wheel, and in you, will reach maximum
> potential or 170 volts 120 times. Your internal
> circuitry, heart, brain, etc. may not be able to
> handle that much disruption without dire
> consequences. This is where the GFCI device
> comes into play.
>
> When a circuit is operating normally the electrical
> current flowing through the Hot wire and the Neutral
> wire have to be the same. When there is a "Short"
> circuit some of the current flows through a different
> path than the Neutral wire. The GFCI device
> monitors the current flow through the Hot and Neutral
> wires and if it detects a difference it will turn off
> electricity to the Hot wire. And it does this quick.
> So quick, in fact, that the device being protected,
> and you, can experience the electricity reaching it's
> maximum potential a maximum of one time. This
> may be enough for you to feel the shock but it's not
> normally enough to cause you severe problems, like
> dying.
>
> The electrical building codes in effect today require
> GFCI protection in locations where it is likely that
> potential alternate ground paths exists, such as
> around plumbing fixtures, outdoor locations, garages
> and such and where water is likely to be around to
> facilitate the flow of electricity.
>
> I consider working on a wheel with both hands wet
> and touching metal parts which may become Hot
> enough of a risk that I won't use my wheel unless
> it is plugged into a known good GFCI protected
> circuit. I believe that a pottery wheel fits with the
> spirit of the electrical codes definitions of high risk
> situations.
>
> And, to be technically correct, it is Ground Fault Circuit
> Interrupter (GFCI) not Ground Fault Interrupter (GFI)
> since the device interrupts power to the circuit
> that is experiencing the ground fault; it does not
> interupt the ground fault itself.
>
> Earl Krueger
> Veneta, Oregon, usa
>
>
>
____________________________________________________________________________
__
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, or change your
> subscription settings here: http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
--
____________________________________________________________________________
__
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, or change your
subscription settings here: http://www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
Taylor Hendrix on tue 18 dec 07
When is is advisable to use GFCI BREAKERS rather than wiring in a GFCI
outlet into the circut?
I rewired my detatched garage but used the existing breakers and GFCI
only in the bathroom area. I'm not too worried about using my
lockerbie on a straight circut but I was planning on plumbing new
water to a cleanup area and haven't decided on how to GFCI protect
that circut.
Interested to hear from the Head.
Taylor, in Rockport TX
On 12/18/07, Earl Krueger wrote:
> Most of the time when I read well recognized
> pottery experts give "expert" advice on subjects
> they may know a little about but do not have a
> deep understanding of I usually chuckle a little
> and then move on to the next topic. But the
> recent advice to remove the GFCI device from
> the circuit you use to power your wheel is not
> only bad advice, it is dangerous advice which
> I can not let slide without comment.
...
Steve Slatin on tue 18 dec 07
Alisha --
There're two different kinds of GFCI's that you commonly find in the home
or studio -- a circuit breaker GFCI and an outlet GFCI. Circuit breaker
GFCI's trip for either a circuit unbalance or an overload. AFAIK, the
outlet breakers typically only trip for an unbalance.
If you're tripping a circuit breaker, it could be either indicating a ground
fault or an overload -- if it's an outlet, it's almost certainly the
unbalance.
So, first -- have you plugged the pugger into different GFCI outlets?
Are you sure that you're using an outlet and a circuit with adequate
capacity for the pugger? Have you tried unplugging everything else
on the circuit first, to see if whatever it is still trips?
If it's an outlet tripping, how is the receptacle rated? Maybe it's
insufficient for the draw the pugger puts onto it.
If it's an outlet that's tripping, and only one outlet will trip and others
won't, perhaps the GFCI is defective.
It's also true that some equipment may trip a GFCI even when it's
working properly -- space heaters sometimes to this, for example.
Maybe with some more details we can zero in on the issue.
Best wishes -- Steve S
Alisha Clarke wrote:
I agree with Earl that GFCI protection is a good safeguard, but what do you
do when you have a device that constantly trips the circuit. I finished the
construction of a new studio attached to my garage this summer ( you can
see pictures of it at http://www.flickr.com/gp/65564173@N00/QKFG29 ). All of
the 110 recepticles are protected with GFCI. However, I found that my new
Peter Pugger VPM-9 trips the GFCI. The only way I could get it to work is to
connect it to a non-GFCI circuit. Right now I'm running an extension cord
from the garage, but I was planning to move the GFCI receptacle on one of
the lines to the second box so I have a non-GFCI outlet in the studio I
could use for the VPM-9.
Should a heavy drawing item like a pugmill still be able to work on GFCI? Is
there an alternative GFCI receptacle that would work for it, or does this
suggest a flaw in the pugmill?
Leesh
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
Pottery by Leesh: www.alishaclarke.com
Pottery Basics: www.potterybasics.com
On Dec 18, 2007 2:17 AM, Earl Krueger wrote:
> Most of the time when I read well recognized
> pottery experts give "expert" advice on subjects
> they may know a little about but do not have a
> deep understanding of I usually chuckle a little
> and then move on to the next topic. But the
> recent advice to remove the GFCI device from
> the circuit you use to power your wheel is not
> only bad advice, it is dangerous advice which
> I can not let slide without comment.
>
> To the person whose wheel trips their GFCI device
> I have a Shimpo VL Whisper and it runs fine on
> a GFCI protected circuit. In fact, I will not run
> it on a circuit that is not GFCI protected as I value
> my life a little more than the few dollars it takes
> to install a GFCI device. I will explain how GFCI
> works and it should become apparent why I feel
> the way I do.
>
> In the USA, modern day 110-120V electrical circuits
> in your home or studio consist of 3 wires. One is the
> "Hot" wire which can be thought of as bringing the
> electricity to the outlet, one is the "Neutral" wire which
> is used to complete the electrical circuit when the power
> switch is "ON" and one is the "Ground" wire which
> is there mostly for safety reasons.
>
> Many people get confused about the difference
> between the Neutral and Ground wires, especially
> since if you follow them back to the power panel you
> will find that they are tied together by a bus bar and
> are therefore at the same electrical potential at that
> point at all times. The real difference between the
> two occurs inside the device you plug into the outlet;
> your wheel for example.
>
> Inside the wheel's electronics package the Hot and
> Neutral wires are connected so that when the power
> switch is in the "ON" position they, along with the
> electronics, form a complete electrical circuit. Current
> flows through both wires. Look closely and you will
> see that both Hot and Neutral are insulated from all
> metal parts that you might touch in order to protect
> you from any electrical current.
>
> But what happens if that insulation should fail or a
> stray wire touch against the metal case. Then the
> metal case, even the wheel head, could become
> Hot and if you were touching that part and something
> else that provided a good return path for the electricity
> you would definetly not have a good day. This is
> where the Ground wire comes into play.
>
> The Ground wire is connected to the metal parts of
> your wheel that do not form a part of the normal
> electrical circuit. If for some reason, as given above,
> the metal case should become Hot then the Ground
> wire will provide a low resistance return path to the
> power panel and since there would most likely be an
> excessive amount of current flowing the circuit
> breaker would trip cutting off the electricity to your
> wheel. So we're protected, right? Well, not really !
>
> You see, it may take a second or more for the
> circuit breaker to trip. In that time the voltage
> at your wheel, and in you, will reach maximum
> potential or 170 volts 120 times. Your internal
> circuitry, heart, brain, etc. may not be able to
> handle that much disruption without dire
> consequences. This is where the GFCI device
> comes into play.
>
> When a circuit is operating normally the electrical
> current flowing through the Hot wire and the Neutral
> wire have to be the same. When there is a "Short"
> circuit some of the current flows through a different
> path than the Neutral wire. The GFCI device
> monitors the current flow through the Hot and Neutral
> wires and if it detects a difference it will turn off
> electricity to the Hot wire. And it does this quick.
> So quick, in fact, that the device being protected,
> and you, can experience the electricity reaching it's
> maximum potential a maximum of one time. This
> may be enough for you to feel the shock but it's not
> normally enough to cause you severe problems, like
> dying.
>
> The electrical building codes in effect today require
> GFCI protection in locations where it is likely that
> potential alternate ground paths exists, such as
> around plumbing fixtures, outdoor locations, garages
> and such and where water is likely to be around to
> facilitate the flow of electricity.
>
> I consider working on a wheel with both hands wet
> and touching metal parts which may become Hot
> enough of a risk that I won't use my wheel unless
> it is plugged into a known good GFCI protected
> circuit. I believe that a pottery wheel fits with the
> spirit of the electrical codes definitions of high risk
> situations.
>
> And, to be technically correct, it is Ground Fault Circuit
> Interrupter (GFCI) not Ground Fault Interrupter (GFI)
> since the device interrupts power to the circuit
> that is experiencing the ground fault; it does not
> interupt the ground fault itself.
>
> Earl Krueger
> Veneta, Oregon, usa
>
>
> ______________________________________________________________________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, or change your
> subscription settings here: http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
--
______________________________________________________________________________
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, or change your
subscription settings here: http://www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
---------------------------------
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Alisha Clarke on tue 18 dec 07
Thanks Larry and Steve,
I have the GFCI outlets on the first outlet in each series, therefore
protecting all of the outlets in the series. There are three series of
outlets in the studio, one 20 amp and two 15 amp. I tried it in each of them
with the same result. However, I don't know the capacity of the GFCI outlet
breakers that the electrician used. It's possible that they are 15 amp. As
Larry indicated, the VPM-9 is rated at 8 amps and should run on any of these
circuits. I wasn't running anything else on them at the time of the test.
The resolution was to use an extension cord to plug the pugmill into a 15
amp circuit outlet in the garage that doesn't have GFCI, and it works there
fine. The GFCI flips immediately when I turn on the pugmill, so I'm inclined
to think that Larry's right, that it's the initial surge that's causing it
to flip. I'm going to look into the possibility of using a heavier duty
GFCI, but I may just switch the GFCI to the second outlet in one of the
series and use the unprotected one for the pugmill.
Thanks for the ideas!
Leesh
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
Pottery by Leesh: www.alishaclarke.com
Pottery Basics: www.potterybasics.com
On Dec 18, 2007 1:59 PM, Steve Slatin wrote:
> Alisha --
>
> There're two different kinds of GFCI's that you commonly find in the home
> or studio -- a circuit breaker GFCI and an outlet GFCI. Circuit breaker
> GFCI's trip for either a circuit unbalance or an overload. AFAIK, the
> outlet breakers typically only trip for an unbalance.
>
> If you're tripping a circuit breaker, it could be either indicating a
> ground
> fault or an overload -- if it's an outlet, it's almost certainly the
> unbalance.
>
> So, first -- have you plugged the pugger into different GFCI outlets?
> Are you sure that you're using an outlet and a circuit with adequate
> capacity for the pugger? Have you tried unplugging everything else
> on the circuit first, to see if whatever it is still trips?
>
> If it's an outlet tripping, how is the receptacle rated? Maybe it's
> insufficient for the draw the pugger puts onto it.
>
> If it's an outlet that's tripping, and only one outlet will trip and
> others
> won't, perhaps the GFCI is defective.
>
> It's also true that some equipment may trip a GFCI even when it's
> working properly -- space heaters sometimes to this, for example.
>
> Maybe with some more details we can zero in on the issue.
>
> Best wishes -- Steve S
>
> Alisha Clarke wrote:
> I agree with Earl that GFCI protection is a good safeguard, but what do
> you
> do when you have a device that constantly trips the circuit. I finished
> the
> construction of a new studio attached to my garage this summer ( you can
> see pictures of it at http://www.flickr.com/gp/65564173@N00/QKFG29 ). All
> of
> the 110 recepticles are protected with GFCI. However, I found that my new
> Peter Pugger VPM-9 trips the GFCI. The only way I could get it to work is
> to
> connect it to a non-GFCI circuit. Right now I'm running an extension cord
> from the garage, but I was planning to move the GFCI receptacle on one of
> the lines to the second box so I have a non-GFCI outlet in the studio I
> could use for the VPM-9.
>
> Should a heavy drawing item like a pugmill still be able to work on GFCI?
> Is
> there an alternative GFCI receptacle that would work for it, or does this
> suggest a flaw in the pugmill?
> Leesh
> ~~~~~~~~~~~~~~~~~~~~~~~~~
> Alisha Clarke
> Pottery by Leesh: www.alishaclarke.com
> Pottery Basics: www.potterybasics.com
>
> On Dec 18, 2007 2:17 AM, Earl Krueger wrote:
>
> > Most of the time when I read well recognized
> > pottery experts give "expert" advice on subjects
> > they may know a little about but do not have a
> > deep understanding of I usually chuckle a little
> > and then move on to the next topic. But the
> > recent advice to remove the GFCI device from
> > the circuit you use to power your wheel is not
> > only bad advice, it is dangerous advice which
> > I can not let slide without comment.
> >
> > To the person whose wheel trips their GFCI device
> > I have a Shimpo VL Whisper and it runs fine on
> > a GFCI protected circuit. In fact, I will not run
> > it on a circuit that is not GFCI protected as I value
> > my life a little more than the few dollars it takes
> > to install a GFCI device. I will explain how GFCI
> > works and it should become apparent why I feel
> > the way I do.
> >
> > In the USA, modern day 110-120V electrical circuits
> > in your home or studio consist of 3 wires. One is the
> > "Hot" wire which can be thought of as bringing the
> > electricity to the outlet, one is the "Neutral" wire which
> > is used to complete the electrical circuit when the power
> > switch is "ON" and one is the "Ground" wire which
> > is there mostly for safety reasons.
> >
> > Many people get confused about the difference
> > between the Neutral and Ground wires, especially
> > since if you follow them back to the power panel you
> > will find that they are tied together by a bus bar and
> > are therefore at the same electrical potential at that
> > point at all times. The real difference between the
> > two occurs inside the device you plug into the outlet;
> > your wheel for example.
> >
> > Inside the wheel's electronics package the Hot and
> > Neutral wires are connected so that when the power
> > switch is in the "ON" position they, along with the
> > electronics, form a complete electrical circuit. Current
> > flows through both wires. Look closely and you will
> > see that both Hot and Neutral are insulated from all
> > metal parts that you might touch in order to protect
> > you from any electrical current.
> >
> > But what happens if that insulation should fail or a
> > stray wire touch against the metal case. Then the
> > metal case, even the wheel head, could become
> > Hot and if you were touching that part and something
> > else that provided a good return path for the electricity
> > you would definetly not have a good day. This is
> > where the Ground wire comes into play.
> >
> > The Ground wire is connected to the metal parts of
> > your wheel that do not form a part of the normal
> > electrical circuit. If for some reason, as given above,
> > the metal case should become Hot then the Ground
> > wire will provide a low resistance return path to the
> > power panel and since there would most likely be an
> > excessive amount of current flowing the circuit
> > breaker would trip cutting off the electricity to your
> > wheel. So we're protected, right? Well, not really !
> >
> > You see, it may take a second or more for the
> > circuit breaker to trip. In that time the voltage
> > at your wheel, and in you, will reach maximum
> > potential or 170 volts 120 times. Your internal
> > circuitry, heart, brain, etc. may not be able to
> > handle that much disruption without dire
> > consequences. This is where the GFCI device
> > comes into play.
> >
> > When a circuit is operating normally the electrical
> > current flowing through the Hot wire and the Neutral
> > wire have to be the same. When there is a "Short"
> > circuit some of the current flows through a different
> > path than the Neutral wire. The GFCI device
> > monitors the current flow through the Hot and Neutral
> > wires and if it detects a difference it will turn off
> > electricity to the Hot wire. And it does this quick.
> > So quick, in fact, that the device being protected,
> > and you, can experience the electricity reaching it's
> > maximum potential a maximum of one time. This
> > may be enough for you to feel the shock but it's not
> > normally enough to cause you severe problems, like
> > dying.
> >
> > The electrical building codes in effect today require
> > GFCI protection in locations where it is likely that
> > potential alternate ground paths exists, such as
> > around plumbing fixtures, outdoor locations, garages
> > and such and where water is likely to be around to
> > facilitate the flow of electricity.
> >
> > I consider working on a wheel with both hands wet
> > and touching metal parts which may become Hot
> > enough of a risk that I won't use my wheel unless
> > it is plugged into a known good GFCI protected
> > circuit. I believe that a pottery wheel fits with the
> > spirit of the electrical codes definitions of high risk
> > situations.
> >
> > And, to be technically correct, it is Ground Fault Circuit
> > Interrupter (GFCI) not Ground Fault Interrupter (GFI)
> > since the device interrupts power to the circuit
> > that is experiencing the ground fault; it does not
> > interupt the ground fault itself.
> >
> > Earl Krueger
> > Veneta, Oregon, usa
> >
> >
> >
> ______________________________________________________________________________
> > Clayart members may send postings to: clayart@lsv.ceramics.org
> >
> > You may look at the archives for the list, post messages, or change your
> > subscription settings here: http://www.acers.org/cic/clayart/
> >
> > Moderator of the list is Mel Jacobson who may be reached at
> > melpots2@visi.com
> >
>
>
>
> --
>
>
> ______________________________________________________________________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, or change your
> subscription settings here: http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
>
>
> ---------------------------------
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>
> ______________________________________________________________________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, or change your
> subscription settings here: http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
--
Steve Slatin on thu 20 dec 07
Alisha --
Breakers should have their capacity marked on the visible surface.
If your electrician was really careful, he may also have had
them marked in s list inside the door of the breaker box.
You may also wish to call the Peter Pugger people and
ask them -- they may have experience with this. Most
equipment, though, can run on a properly configured GFCI.
Best wishes -- Steve S
Alisha Clarke wrote:
Thanks Larry and Steve,
I have the GFCI outlets on the first outlet in each series, therefore
protecting all of the outlets in the series. There are three series of
outlets in the studio, one 20 amp and two 15 amp. I tried it in each of them
with the same result. However, I don't know the capacity of the GFCI outlet
breakers that the electrician used. It's possible that they are 15 amp. As
Larry indicated, the VPM-9 is rated at 8 amps and should run on any of these
circuits. I wasn't running anything else on them at the time of the test.
The resolution was to use an extension cord to plug the pugmill into a 15
amp circuit outlet in the garage that doesn't have GFCI, and it works there
fine. The GFCI flips immediately when I turn on the pugmill, so I'm inclined
to think that Larry's right, that it's the initial surge that's causing it
to flip. I'm going to look into the possibility of using a heavier duty
GFCI, but I may just switch the GFCI to the second outlet in one of the
series and use the unprotected one for the pugmill.
Thanks for the ideas!
Leesh
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
---------------------------------
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