I am slowly fixing all the annoying features of this house we bought.
I may never get all of them corrected. But have a temporary solution
to one.

The house is mostly wired with 14 gauge wire and 15 amp breakers. So
the drill press with a 1.5 hp motor will pop the circuit breaker if
used for very long. The long term solution is to add a 220 volt 20 amp
circuit, change out the motor for a three phase motor and use a VFD.
But there are lots of other things that are more pressing.

So the temporary fix is to add a 40 ufd run capacitor in parallel with
the motor. That corrects the power factor a bit and drops the current
enough that the circuit breaker does not pop. The savings in power is
pretty much nothing, but having the power stay on is priceless.

Dan

" fired this volley in news:2d790886-
:

So the temporary fix is to add a 40 ufd run capacitor in parallel with
the motor. That corrects the power factor a bit and drops the current
enough that the circuit breaker does not pop. The savings in power is
pretty much nothing, but having the power stay on is priceless.

Dan,

I know it would be much more expensive, but how about an active power
factor controller? That would handle correction at all loads, and also
wouldn't present that potential "dead short" across the line, should the
cap decide to upchuck.

LLoyd

On Thu, 8 Jul 2010 05:20:26 -0700 (PDT), "
wrote:

I am slowly fixing all the annoying features of this house we bought.
I may never get all of them corrected. But have a temporary solution
to one.

The house is mostly wired with 14 gauge wire and 15 amp breakers. So
the drill press with a 1.5 hp motor will pop the circuit breaker if
used for very long. The long term solution is to add a 220 volt 20 amp
circuit, change out the motor for a three phase motor and use a VFD.
But there are lots of other things that are more pressing.

So the temporary fix is to add a 40 ufd run capacitor in parallel with
the motor. That corrects the power factor a bit and drops the current
enough that the circuit breaker does not pop. The savings in power is
pretty much nothing, but having the power stay on is priceless.

Dan

If you can change the voltage, leave the 14G wire and run it 240V
15A. Change out or blank off other outlets on that circut.

Thank You,
Randy

Remove 333 from email address to reply.

On 7/8/2010 5:24 AM, Lloyd E. Sponenburgh wrote:
fired this volley in news:2d790886-
:

So the temporary fix is to add a 40 ufd run capacitor in parallel with
the motor. That corrects the power factor a bit and drops the current
enough that the circuit breaker does not pop. The savings in power is
pretty much nothing, but having the power stay on is priceless.

Dan,

I know it would be much more expensive, but how about an active power
factor controller? That would handle correction at all loads, and also
wouldn't present that potential "dead short" across the line, should the
cap decide to upchuck.

I stumbled across this Power Factor info just now:
http://ecmweb.com/power_quality/reso..._effects_0201/
http://ecmweb.com/powerquality/capac...esonance_0301/
It is a cogent read, notwithstanding the equation error on page 1
under "Harmonic and reactive currents".

[Reader's Digest Version:
Low PF can *also* be caused by a 'current resonance' in the
load, which can also have the effect of distorting the voltage waveform.
(This is in addition to the more traditional 'impedance mismatch' cause
of low Power Factor, addressed with parallel capacitance.)]

If you had a nifty Hall Effect current adapter, you could clamp it on to
the line supplying your drill press and determine if your DP is trying to
be a radio transmitter.

As you see at the end of Page 1, the author suggests that an
RC filter tuned to snub the frequency of the 'current resonance' can
reduce it significantly, improving system reliability.

--Winston

On Jul 8, 9:41*am, Randy wrote:


If you can change the voltage, leave the 14G *wire and run it 240V
15A. * Change out or blank off other outlets on that circut.

Thank You,
Randy


That is a good idea and I looked at the motor. It is a 120 volt non
reversible motor. 8-(. The drill press manufacturer probably saved a
dollar or two.
Dan
..

On Jul 8, 8:24*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:


I know it would be much more expensive, but how about an active power
factor controller? *That would handle correction at all loads, and also
wouldn't present that potential "dead short" across the line, should the
cap decide to upchuck.

LLoyd

The cap is one I got at the recycling yard and did not cost me
anything. Probably came out of a air conditioner. If it does short,
the circuit breaker should keep things from becoming a disaster.
Since the load is an electric motor, I am not sure how I could build
an active power factor controler.

On Jul 8, 9:53*am, Winston wrote:
On 7/8/2010 5:24 AM, Lloyd E. Sponenburgh wrote:

*fired this volley in news:2d790886-
:

So the temporary fix is to add a 40 ufd run capacitor in parallel with
the motor. *That corrects the power factor a bit and drops the current
enough that the circuit breaker does not pop. *The savings in power is
pretty much nothing, but having the power stay on is priceless.

Dan,

I know it would be much more expensive, but how about an active power
factor controller? *That would handle correction at all loads, and also
wouldn't present that potential "dead short" across the line, should the
cap decide to upchuck.

I stumbled across this Power Factor info just now:http://ecmweb.com/power_quality/reso...esonance_0301/
It is a cogent read, notwithstanding the equation error on page 1
under "Harmonic and reactive currents".

[Reader's Digest Version:
Low PF can *also* be caused by a 'current resonance' in the
load, which can also have the effect of distorting the voltage waveform.
(This is in addition to the more traditional 'impedance mismatch' cause
of low Power Factor, addressed with parallel capacitance.)]

If you had a nifty Hall Effect current adapter, you could clamp it on to
the line supplying your drill press and determine if your DP is trying to
be a radio transmitter. *

As you see at the end of Page 1, the author suggests that an
RC filter tuned to snub the frequency of the 'current resonance' can
reduce it significantly, improving system reliability.

--Winston

Interesting. But I think that they are talking about non-linear
loads, not electric motors.

Dan

" fired this volley in news:0ba0bbfc-
:

Since the load is an electric motor, I am not sure how I could build
an active power factor controler.

There are commercial power factor controllers for motors that are usually
lightly loaded, and only occasionally under normal load. They start at
about $10.

I have one made many years ago -- "The Green Plug".

LLoyd

Dan sez:
"The house is mostly wired with 14 gauge wire and 15 amp breakers. So
the drill press with a 1.5 hp motor will pop the circuit breaker if
used for very long."

AFAIK, there should be no time limit as to how long a given load operates from a CB. Could it be
your motor is defective and draws excessive current after it warms up? Figuring 1000 Watts per HP
(Allowing for normal PF and efficiency) a fully loaded 1.5 HP motor on 120 volts should not trip a
15 amp breaker. The aproximate 12.5 amps is well within the 15 amp rated CB. It is highly unlikely
the drill press will be fully loaded to 1.5 HP all the time it is on; thus it appears something is
wrong with the motor or the CB is the real culprit.

Bob Swinney

On Jul 8, 12:42*pm, "Robert Swinney" wrote:
Dan sez:
"The house is mostly wired with 14 gauge wire and 15 amp breakers. *So
the drill press with a 1.5 hp motor will pop the circuit breaker if
used for very long."

AFAIK, there should be no time limit as to how long a given load operates from a CB. *Could it be
your motor is defective and draws excessive current after it warms up? *Figuring 1000 Watts per HP
(Allowing for normal PF and efficiency) a fully loaded 1.5 HP motor on 120 volts should not trip a
15 amp breaker. *The aproximate 12.5 amps is well within the 15 amp rated CB. *It is highly unlikely
the drill press will be fully loaded to 1.5 HP all the time it is on; thus it appears something is
wrong with the motor or the CB is the real culprit.

Bob Swinney


Interesting problem; What is the drill capacity? Do you REALLY need
1.5 HP on it?

These motors are notoriously inefficient, as are most split-phase
motors.

Consider: 1.5 HP x 746 Watts/HP / .67 efficiency = 1670 Watts maximum
demand. (I'm estimating the efficiency based on pool pump motors).
Supply: 115 VAC x 15 Amps = 1725 Watts. Therefore pretty marginal
set-up if the motor is loaded to capacity.

The circuit breakers have probably deteriorated over the years and the
motor efficiency may very well be less than .67... But unless the
motor is faulty or loaded to capacity, the breaker should not trip.
Can you check the running current with a clamp-on meter?

Wolfgang

On Jul 8, 12:42*pm, "Robert Swinney" wrote:
Dan sez:
"The house is mostly wired with 14 gauge wire and 15 amp breakers. *So
the drill press with a 1.5 hp motor will pop the circuit breaker if
used for very long."

AFAIK, there should be no time limit as to how long a given load operates from a CB. *Could it be
your motor is defective and draws excessive current after it warms up? *Figuring 1000 Watts per HP
(Allowing for normal PF and efficiency) a fully loaded 1.5 HP motor on 120 volts should not trip a
15 amp breaker. *The aproximate 12.5 amps is well within the 15 amp rated CB. *It is highly unlikely
the drill press will be fully loaded to 1.5 HP all the time it is on; thus it appears something is
wrong with the motor or the CB is the real culprit.

Bob Swinney

Looking in the W.W. Grainger catalog I find a 1.5 hp motors with full
load amps from 15.2 to 19.8. I would not be surprised if the
circuit breaker is off a little, but think the motor is the major
culprit and has a low power factor.

Dan

On Jul 8, 1:29*pm, wolfgang wrote:


Interesting problem; *What is the drill capacity? *Do you REALLY need
1.5 HP on it?


The circuit breakers have probably deteriorated over the years and the
motor efficiency may very well be less than .67... * But unless the
motor is faulty or loaded to capacity, the breaker should not trip.
Can you check the running current with a clamp-on meter?

Wolfgang

The drill press has a #2 MT and I have a 5/8 cap chuck on it. And I
really do not need a 1.5 hp motor on it, but I bought it used and that
is what it had. I wanted to check the running current and have a
clamp on adapter that is used with a regular multimeter. But the 200
mv range of my DMM does not zero. Otherwise I would have posted what
the power factor of the motor is. The motor efficiency is probably
well above .67, but the power factor is likely to be very poor.

Dan

" wrote:

I am slowly fixing all the annoying features of this house we bought.
I may never get all of them corrected. But have a temporary solution
to one.

The house is mostly wired with 14 gauge wire and 15 amp breakers. So
the drill press with a 1.5 hp motor will pop the circuit breaker if
used for very long. The long term solution is to add a 220 volt 20 amp
circuit, change out the motor for a three phase motor and use a VFD.
But there are lots of other things that are more pressing.

So the temporary fix is to add a 40 ufd run capacitor in parallel with
the motor. That corrects the power factor a bit and drops the current
enough that the circuit breaker does not pop. The savings in power is
pretty much nothing, but having the power stay on is priceless.


Most residential services are billed in KWH instead of KVAR. I hope you are not in a KVAR
billing area. That could make running rpc's expensive.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

"Robert Swinney" wrote in

AFAIK, there should be no time limit as to how long a given load
operates from a CB.

Household circuit breakers have a definite time based response to current.
They have dual overcurrent sensing methods; thermal and magnetic. The
thermal portion reacts to long duration overload situations and the
magnetic portion reacts quickly to short circuits.

Any good breaker will carry an overload up to say 150% for at least several
minutes without tripping. Higher overloads, say 300% should trip it in
several seconds.

Being in the panel beside another heavily loaded breaker tends to reduce
the breaker's ability to carry it's rated current due to mutual heating.

On Jul 9, 12:21*am, Wes wrote:

Most residential services are billed in KWH instead of KVAR. *I hope you are not in a KVAR
billing area. *That could make running rpc's expensive.


I do not think there is anyplace where residential services are billed
in KVA.

Dan

On 2010-07-09, wrote:
On Jul 9, 12:21*am, Wes wrote:

Most residential services are billed in KWH instead of KVAR. *I hope you are not in a KVAR
billing area. *That could make running rpc's expensive.


I do not think there is anyplace where residential services are billed
in KVA.

It happens when you talk them into running three phase to your
house. :-)

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Don sez:
"It happens when you talk them into running three phase to your
house. :-)"

Which is the best reason to build your own 3-Phase system. And I don't mean buy an individual VFD
for each machine. See many articles on Rotary Phase Convertors.

Bob Swinney

"DoN. Nichols" wrote in message
...
On 2010-07-09, wrote:
On Jul 9, 12:21 am, Wes wrote:

Most residential services are billed in KWH instead of KVAR. I hope you are not in a KVAR
billing area. That could make running rpc's expensive.


I do not think there is anyplace where residential services are billed
in KVA.


Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Sat, 10 Jul 2010 12:06:40 -0500, "Robert Swinney"
wrote:

Don sez:
"It happens when you talk them into running three phase to your
house. :-)"

Im sure it depends on the specific utility and the tariffs it operates
under, but I've had two small (100~200 amp) 3-phase services and also
worked in shops with the same and none had a power factor penalty, or
even service equipment capable of measuring power factor. On the other
hand, the rate was a bit higher than residential, so perhaps the
utility gets it's due that way.

--
Ned Simmons