Rocksolid Light

Welcome to novaBBS (click a section below)

mail  files  register  newsreader  groups  login

Message-ID:  

I can't drive 55. I'm looking forward to not being able to drive 65, either.

interests / rec.woodworking / Re: Amperage for 5HP table saw?

SubjectAuthor
* Re: Amperage for 5HP table saw?Bob Davis
+* Re: Amperage for 5HP table saw?Joe Gwinn
|+- Re: Amperage for 5HP table saw?krw
|+- Re: Amperage for 5HP table saw?Clare Snyder
|`- Re: Amperage for 5HP table saw?Bob Davis
`* Re: Amperage for 5HP table saw?Clare Snyder
 `* Re: Amperage for 5HP table saw?Bob Davis
  +- Re: Amperage for 5HP table saw?Scott Lurndal
  +- Re: Amperage for 5HP table saw?krw
  +* Re: Amperage for 5HP table saw?J. Clarke
  |+- Re: Amperage for 5HP table saw?Markem618
  |`- Re: Amperage for 5HP table saw?Clare Snyder
  `- Re: Amperage for 5HP table saw?Bob Davis

1
Re: Amperage for 5HP table saw?

<2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5189&group=rec.woodworking#5189

  copy link   Newsgroups: rec.woodworking
X-Received: by 2002:a05:620a:2903:: with SMTP id m3mr2588614qkp.452.1636416444974;
Mon, 08 Nov 2021 16:07:24 -0800 (PST)
X-Received: by 2002:a05:6808:1485:: with SMTP id e5mr2071750oiw.172.1636416444614;
Mon, 08 Nov 2021 16:07:24 -0800 (PST)
Path: i2pn2.org!i2pn.org!paganini.bofh.team!weretis.net!feeder8.news.weretis.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: rec.woodworking
Date: Mon, 8 Nov 2021 16:07:24 -0800 (PST)
In-Reply-To: <020320040720322031%comfortable@work.com>
Injection-Info: google-groups.googlegroups.com; posting-host=73.55.151.166; posting-account=Pu0UeAoAAABPhKXXMI9Wp2n-KFrwpmWm
NNTP-Posting-Host: 73.55.151.166
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com>
Subject: Re: Amperage for 5HP table saw?
From: wrobertd...@gmail.com (Bob Davis)
Injection-Date: Tue, 09 Nov 2021 00:07:24 +0000
Content-Type: text/plain; charset="UTF-8"
 by: Bob Davis - Tue, 9 Nov 2021 00:07 UTC

On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
> In article <1078204646.761648@smirk>,
> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
> > What amperage breaker does one need for a 5HP table saw on a 240V
> > single phase circuit?
> >
> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
> > (look it up in the NEC sometime), this means a 25 A breaker would be
> > borderline sufficient, and that a 30A breaker should be generous.
> > With a slow breaker (not a fuse), there should be no problems with the
> > startup surge of the motor tripping the breaker.
> Using Ohm's law this is a relatively simple question to answer...
> 1 horsepower = 745.7 watts
> Power (watts) = I (amperage) x E (voltage)
> When you have two values for the variables in the equation you can
> figure out the third.
> P 3728.5 (watts 1 HP x 5)
> Therefore I = --- or I = ------
> E 230 volts
>
> 230 volts = 16.21 amps
> 240 volts = 15.53 amps
>
> Using the "80% rule", a 20 amp breaker should not exceed a continuous
> load above 16 amps. It seems to me, that with the proper type of "slow"
> breaker, you should be OK with a 20 amp breaker.
>
> Joe
>
> PS
> I am not an electrician or an electrical engineer. In fact, I have
> never even played one on TV.

Ohm's law is for DC. It does not apply to AC.

Re: Amperage for 5HP table saw?

<5jjjogpop9nkl5ae3helpskq893flmj8hr@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5190&group=rec.woodworking#5190

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!feeder1.feed.usenet.farm!feed.usenet.farm!tr1.eu1.usenetexpress.com!feeder.usenetexpress.com!tr1.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!buffer1.nntp.dca1.giganews.com!buffer2.nntp.dca1.giganews.com!news.giganews.com.POSTED!not-for-mail
NNTP-Posting-Date: Mon, 08 Nov 2021 19:30:47 -0600
From: joegw...@comcast.net (Joe Gwinn)
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Date: Mon, 08 Nov 2021 20:30:47 -0500
Message-ID: <5jjjogpop9nkl5ae3helpskq893flmj8hr@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com>
User-Agent: ForteAgent/8.00.32.1272
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 49
X-Usenet-Provider: http://www.giganews.com
X-Trace: sv3-Gcs5vZx3a+SWx2//QCqOIBsRVsnioeL4QgmfmsywJW5OzBivFxxm3vztinoKuCDIDKEmhjtjXLhuYLn!w10KCtpD5auuF1isv9Gp1+YICli5gBvnrXiszFm7/jYULjecV572aawWNcz7vDvsS9IDAeM=
X-Complaints-To: abuse@giganews.com
X-DMCA-Notifications: http://www.giganews.com/info/dmca.html
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
X-Original-Bytes: 3126
 by: Joe Gwinn - Tue, 9 Nov 2021 01:30 UTC

On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
<wrobertdavis@gmail.com> wrote:

>On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>> In article <1078204646.761648@smirk>,
>> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>> > What amperage breaker does one need for a 5HP table saw on a 240V
>> > single phase circuit?
>> >
>> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>> > (look it up in the NEC sometime), this means a 25 A breaker would be
>> > borderline sufficient, and that a 30A breaker should be generous.
>> > With a slow breaker (not a fuse), there should be no problems with the
>> > startup surge of the motor tripping the breaker.
>> Using Ohm's law this is a relatively simple question to answer...
>> 1 horsepower = 745.7 watts
>> Power (watts) = I (amperage) x E (voltage)
>> When you have two values for the variables in the equation you can
>> figure out the third.
>> P 3728.5 (watts 1 HP x 5)
>> Therefore I = --- or I = ------
>> E 230 volts
>>
>> 230 volts = 16.21 amps
>> 240 volts = 15.53 amps
>>
>> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>> load above 16 amps. It seems to me, that with the proper type of "slow"
>> breaker, you should be OK with a 20 amp breaker.
>>
>> Joe
>>
>> PS
>> I am not an electrician or an electrical engineer. In fact, I have
>> never even played one on TV.
>
>Ohm's law is for DC. It does not apply to AC.

Sure it does, for RMS volts and amps, and pure resistances (like metal
wires and components).

Motors and inductors and capacitors are a different kettle of fish. An
ordinary ohmmeter measures DC resistance, which for an inductor is the
resistance of the copper wire winding, but AC current and voltage are
connected by AC reactance., which will be far larger than the DC
resistance at the usual operating frequency of that inductor.

Joe Gwinn

Re: Amperage for 5HP table saw?

<hekjogpf8cd7625fb2lcipi8rncms1pkf5@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5192&group=rec.woodworking#5192

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!paganini.bofh.team!weretis.net!feeder8.news.weretis.net!ecngs!feeder2.ecngs.de!178.20.174.213.MISMATCH!feeder1.feed.usenet.farm!feed.usenet.farm!peer03.ams4!peer.am4.highwinds-media.com!peer02.iad!feed-me.highwinds-media.com!news.highwinds-media.com!fx42.iad.POSTED!not-for-mail
From: krw...@notreal.com
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Message-ID: <hekjogpf8cd7625fb2lcipi8rncms1pkf5@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <5jjjogpop9nkl5ae3helpskq893flmj8hr@4ax.com>
User-Agent: ForteAgent/8.00.32.1272
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 64
X-Complaints-To: abuse@easynews.com
Organization: Forte - www.forteinc.com
X-Complaints-Info: Please be sure to forward a copy of ALL headers otherwise we will be unable to process your complaint properly.
Date: Mon, 08 Nov 2021 20:59:41 -0500
X-Received-Bytes: 3546
 by: krw...@notreal.com - Tue, 9 Nov 2021 01:59 UTC

On Mon, 08 Nov 2021 20:30:47 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

>On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
><wrobertdavis@gmail.com> wrote:
>
>>On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>>> In article <1078204646.761648@smirk>,
>>> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>>> > What amperage breaker does one need for a 5HP table saw on a 240V
>>> > single phase circuit?
>>> >
>>> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>>> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>>> > (look it up in the NEC sometime), this means a 25 A breaker would be
>>> > borderline sufficient, and that a 30A breaker should be generous.
>>> > With a slow breaker (not a fuse), there should be no problems with the
>>> > startup surge of the motor tripping the breaker.
>>> Using Ohm's law this is a relatively simple question to answer...
>>> 1 horsepower = 745.7 watts
>>> Power (watts) = I (amperage) x E (voltage)
>>> When you have two values for the variables in the equation you can
>>> figure out the third.
>>> P 3728.5 (watts 1 HP x 5)
>>> Therefore I = --- or I = ------
>>> E 230 volts
>>>
>>> 230 volts = 16.21 amps
>>> 240 volts = 15.53 amps
>>>
>>> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>>> load above 16 amps. It seems to me, that with the proper type of "slow"
>>> breaker, you should be OK with a 20 amp breaker.
>>>
>>> Joe
>>>
>>> PS
>>> I am not an electrician or an electrical engineer. In fact, I have
>>> never even played one on TV.
>>
>>Ohm's law is for DC. It does not apply to AC.
>
>Sure it does, for RMS volts and amps, and pure resistances (like metal
>wires and components).
>
>Motors and inductors and capacitors are a different kettle of fish. An
>ordinary ohmmeter measures DC resistance, which for an inductor is the
>resistance of the copper wire winding, but AC current and voltage are
>connected by AC reactance., which will be far larger than the DC
>resistance at the usual operating frequency of that inductor.

A motor is a little different than an inductor. A motor is doing
"work". If the motor were 100% efficient, it would look like a pure
resistor. They aren't, of course, but the more efficient they are,
the closer to a resistor they appear.

80% efficiency for fully loaded small motors isn't too far off but
probably a little high. They get worse when lightly loaded but for
figuring circuit size, the fully loaded numbers are used. A safety
factor of another 20% is a good idea (if not code). Motors can be
overloaded. ;-)

Re: Amperage for 5HP table saw?

<2mmjogd966bv5ek5s5s10ioe1sg0oln6au@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5193&group=rec.woodworking#5193

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: cla...@snyder.on.ca (Clare Snyder)
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Date: Mon, 08 Nov 2021 21:25:44 -0500
Organization: A noiseless patient Spider
Lines: 60
Message-ID: <2mmjogd966bv5ek5s5s10ioe1sg0oln6au@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <5jjjogpop9nkl5ae3helpskq893flmj8hr@4ax.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Injection-Info: reader02.eternal-september.org; posting-host="c977f46e1d3cfe0886916e1f112b66b8";
logging-data="4528"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/6pDsrHzng6EY7VnbvDwo9"
User-Agent: ForteAgent/8.00.32.1272
Cancel-Lock: sha1:YtlovEBgNvFHcSwUh2YA8+qPHN8=
 by: Clare Snyder - Tue, 9 Nov 2021 02:25 UTC

On Mon, 08 Nov 2021 20:30:47 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

>On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
><wrobertdavis@gmail.com> wrote:
>
>>On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>>> In article <1078204646.761648@smirk>,
>>> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>>> > What amperage breaker does one need for a 5HP table saw on a 240V
>>> > single phase circuit?
>>> >
>>> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>>> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>>> > (look it up in the NEC sometime), this means a 25 A breaker would be
>>> > borderline sufficient, and that a 30A breaker should be generous.
>>> > With a slow breaker (not a fuse), there should be no problems with the
>>> > startup surge of the motor tripping the breaker.
>>> Using Ohm's law this is a relatively simple question to answer...
>>> 1 horsepower = 745.7 watts
>>> Power (watts) = I (amperage) x E (voltage)
>>> When you have two values for the variables in the equation you can
>>> figure out the third.
>>> P 3728.5 (watts 1 HP x 5)
>>> Therefore I = --- or I = ------
>>> E 230 volts
>>>
>>> 230 volts = 16.21 amps
>>> 240 volts = 15.53 amps
>>>
>>> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>>> load above 16 amps. It seems to me, that with the proper type of "slow"
>>> breaker, you should be OK with a 20 amp breaker.
>>>
>>> Joe
>>>
>>> PS
>>> I am not an electrician or an electrical engineer. In fact, I have
>>> never even played one on TV.
>>
>>Ohm's law is for DC. It does not apply to AC.
>
>Sure it does, for RMS volts and amps, and pure resistances (like metal
>wires and components).
>
>Motors and inductors and capacitors are a different kettle of fish. An
>ordinary ohmmeter measures DC resistance, which for an inductor is the
>resistance of the copper wire winding, but AC current and voltage are
>connected by AC reactance., which will be far larger than the DC
>resistance at the usual operating frequency of that inductor.
>
>Joe Gwinn
You will want a "high magnetic" breaker - which, fortunately for you
most "twinned" breakers are (at leat all Square D QO breakers are ). I
ended up using a twinned breaker for my central vac (120 volt 12 amp)
because it quite occaisionally tripped the single standard 15 amp
breaker on start-up and a single high magnetic breaker was not
readilly available locally and cost more to order in than my local
supplier charged for the twinned breaker. Hasn't tripped since (about
3 years) - and it tripped on 3 different single breakers - - -

Re: Amperage for 5HP table saw?

<q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5194&group=rec.woodworking#5194

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: cla...@snyder.on.ca (Clare Snyder)
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Date: Mon, 08 Nov 2021 21:28:50 -0500
Organization: A noiseless patient Spider
Lines: 43
Message-ID: <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Injection-Info: reader02.eternal-september.org; posting-host="c977f46e1d3cfe0886916e1f112b66b8";
logging-data="4528"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19BWkpCYc6QCPfPo4lHoDFz"
User-Agent: ForteAgent/8.00.32.1272
Cancel-Lock: sha1:fRvdG/Quct1nurJyK5WJpaQMMHE=
 by: Clare Snyder - Tue, 9 Nov 2021 02:28 UTC

On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
<wrobertdavis@gmail.com> wrote:

>On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>> In article <1078204646.761648@smirk>,
>> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>> > What amperage breaker does one need for a 5HP table saw on a 240V
>> > single phase circuit?
>> >
>> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>> > (look it up in the NEC sometime), this means a 25 A breaker would be
>> > borderline sufficient, and that a 30A breaker should be generous.
>> > With a slow breaker (not a fuse), there should be no problems with the
>> > startup surge of the motor tripping the breaker.
>> Using Ohm's law this is a relatively simple question to answer...
>> 1 horsepower = 745.7 watts
>> Power (watts) = I (amperage) x E (voltage)
>> When you have two values for the variables in the equation you can
>> figure out the third.
>> P 3728.5 (watts 1 HP x 5)
>> Therefore I = --- or I = ------
>> E 230 volts
>>
>> 230 volts = 16.21 amps
>> 240 volts = 15.53 amps
>>
>> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>> load above 16 amps. It seems to me, that with the proper type of "slow"
>> breaker, you should be OK with a 20 amp breaker.
>>
>> Joe
>>
>> PS
>> I am not an electrician or an electrical engineer. In fact, I have
>> never even played one on TV.
>
>Ohm's law is for DC. It does not apply to AC.
Yes it does - the R just means reactance instead of resistance -
wheather inductive or capacitive. With resistive loads it's the same
as with DC - read the resistance on your ohm-meter. With "inductive
loads" the reactance will always be higher than the resistance (draws
less current)

Re: Amperage for 5HP table saw?

<132a125f-3494-45a4-874d-1775d476dfe5n@googlegroups.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5217&group=rec.woodworking#5217

  copy link   Newsgroups: rec.woodworking
X-Received: by 2002:a05:622a:288:: with SMTP id z8mr17311422qtw.75.1636550377909;
Wed, 10 Nov 2021 05:19:37 -0800 (PST)
X-Received: by 2002:aca:b846:: with SMTP id i67mr12572999oif.105.1636550377564;
Wed, 10 Nov 2021 05:19:37 -0800 (PST)
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: rec.woodworking
Date: Wed, 10 Nov 2021 05:19:37 -0800 (PST)
In-Reply-To: <5jjjogpop9nkl5ae3helpskq893flmj8hr@4ax.com>
Injection-Info: google-groups.googlegroups.com; posting-host=73.55.151.166; posting-account=Pu0UeAoAAABPhKXXMI9Wp2n-KFrwpmWm
NNTP-Posting-Host: 73.55.151.166
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com>
<2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <5jjjogpop9nkl5ae3helpskq893flmj8hr@4ax.com>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <132a125f-3494-45a4-874d-1775d476dfe5n@googlegroups.com>
Subject: Re: Amperage for 5HP table saw?
From: wrobertd...@gmail.com (Bob Davis)
Injection-Date: Wed, 10 Nov 2021 13:19:37 +0000
Content-Type: text/plain; charset="UTF-8"
 by: Bob Davis - Wed, 10 Nov 2021 13:19 UTC

On Monday, November 8, 2021 at 7:30:56 PM UTC-6, Joe Gwinn wrote:
> On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
> <wrober...@gmail.com> wrote:
>
> >On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
> >> In article <1078204646.761648@smirk>,
> >> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
> >> > What amperage breaker does one need for a 5HP table saw on a 240V
> >> > single phase circuit?
> >> >
> >> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
> >> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
> >> > (look it up in the NEC sometime), this means a 25 A breaker would be
> >> > borderline sufficient, and that a 30A breaker should be generous.
> >> > With a slow breaker (not a fuse), there should be no problems with the
> >> > startup surge of the motor tripping the breaker.
> >> Using Ohm's law this is a relatively simple question to answer...
> >> 1 horsepower = 745.7 watts
> >> Power (watts) = I (amperage) x E (voltage)
> >> When you have two values for the variables in the equation you can
> >> figure out the third.
> >> P 3728.5 (watts 1 HP x 5)
> >> Therefore I = --- or I = ------
> >> E 230 volts
> >>
> >> 230 volts = 16.21 amps
> >> 240 volts = 15.53 amps
> >>
> >> Using the "80% rule", a 20 amp breaker should not exceed a continuous
> >> load above 16 amps. It seems to me, that with the proper type of "slow"
> >> breaker, you should be OK with a 20 amp breaker.
> >>
> >> Joe
> >>
> >> PS
> >> I am not an electrician or an electrical engineer. In fact, I have
> >> never even played one on TV.
> >
> >Ohm's law is for DC. It does not apply to AC.
> Sure it does, for RMS volts and amps, and pure resistances (like metal
> wires and components).
>
> Motors and inductors and capacitors are a different kettle of fish. An
> ordinary ohmmeter measures DC resistance, which for an inductor is the
> resistance of the copper wire winding, but AC current and voltage are
> connected by AC reactance., which will be far larger than the DC
> resistance at the usual operating frequency of that inductor.
>
> Joe Gwinn
You are right in the theory. In practice, doing calculations about motor current with simple ohm's law does not work because a motor is not a pure resistive load.

Re: Amperage for 5HP table saw?

<2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5218&group=rec.woodworking#5218

  copy link   Newsgroups: rec.woodworking
X-Received: by 2002:a37:9544:: with SMTP id x65mr12714648qkd.275.1636550557869;
Wed, 10 Nov 2021 05:22:37 -0800 (PST)
X-Received: by 2002:a05:6830:4486:: with SMTP id r6mr12488244otv.251.1636550557365;
Wed, 10 Nov 2021 05:22:37 -0800 (PST)
Path: i2pn2.org!i2pn.org!aioe.org!news.uzoreto.com!fu-berlin.de!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: rec.woodworking
Date: Wed, 10 Nov 2021 05:22:37 -0800 (PST)
In-Reply-To: <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com>
Injection-Info: google-groups.googlegroups.com; posting-host=73.55.151.166; posting-account=Pu0UeAoAAABPhKXXMI9Wp2n-KFrwpmWm
NNTP-Posting-Host: 73.55.151.166
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com>
<2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com>
Subject: Re: Amperage for 5HP table saw?
From: wrobertd...@gmail.com (Bob Davis)
Injection-Date: Wed, 10 Nov 2021 13:22:37 +0000
Content-Type: text/plain; charset="UTF-8"
 by: Bob Davis - Wed, 10 Nov 2021 13:22 UTC

On Monday, November 8, 2021 at 8:28:53 PM UTC-6, Clare Snyder wrote:
> On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
> <wrober...@gmail.com> wrote:
> >On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
> >> In article <1078204646.761648@smirk>,
> >> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
> >> > What amperage breaker does one need for a 5HP table saw on a 240V
> >> > single phase circuit?
> >> >
> >> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
> >> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
> >> > (look it up in the NEC sometime), this means a 25 A breaker would be
> >> > borderline sufficient, and that a 30A breaker should be generous.
> >> > With a slow breaker (not a fuse), there should be no problems with the
> >> > startup surge of the motor tripping the breaker.
> >> Using Ohm's law this is a relatively simple question to answer...
> >> 1 horsepower = 745.7 watts
> >> Power (watts) = I (amperage) x E (voltage)
> >> When you have two values for the variables in the equation you can
> >> figure out the third.
> >> P 3728.5 (watts 1 HP x 5)
> >> Therefore I = --- or I = ------
> >> E 230 volts
> >>
> >> 230 volts = 16.21 amps
> >> 240 volts = 15.53 amps
> >>
> >> Using the "80% rule", a 20 amp breaker should not exceed a continuous
> >> load above 16 amps. It seems to me, that with the proper type of "slow"
> >> breaker, you should be OK with a 20 amp breaker.
> >>
> >> Joe
> >>
> >> PS
> >> I am not an electrician or an electrical engineer. In fact, I have
> >> never even played one on TV.
> >
> >Ohm's law is for DC. It does not apply to AC.
> Yes it does - the R just means reactance instead of resistance -
> wheather inductive or capacitive. With resistive loads it's the same
> as with DC - read the resistance on your ohm-meter. With "inductive
> loads" the reactance will always be higher than the resistance (draws
> less current)

What is a real world example of purely resistive load supplied by AC?

Re: Amperage for 5HP table saw?

<tTQiJ.36994$OB3.8029@fx06.iad>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5219&group=rec.woodworking#5219

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!aioe.org!news.uzoreto.com!news-out.netnews.com!news.alt.net!fdc2.netnews.com!peer02.ams1!peer.ams1.xlned.com!news.xlned.com!peer02.iad!feed-me.highwinds-media.com!news.highwinds-media.com!fx06.iad.POSTED!not-for-mail
X-newsreader: xrn 9.03-beta-14-64bit
Sender: scott@dragon.sl.home (Scott Lurndal)
From: sco...@slp53.sl.home (Scott Lurndal)
Reply-To: slp53@pacbell.net
Subject: Re: Amperage for 5HP table saw?
Newsgroups: rec.woodworking
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com> <2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com>
Lines: 6
Message-ID: <tTQiJ.36994$OB3.8029@fx06.iad>
X-Complaints-To: abuse@usenetserver.com
NNTP-Posting-Date: Wed, 10 Nov 2021 14:42:33 UTC
Organization: UsenetServer - www.usenetserver.com
Date: Wed, 10 Nov 2021 14:42:33 GMT
X-Received-Bytes: 993
 by: Scott Lurndal - Wed, 10 Nov 2021 14:42 UTC

Bob Davis <wrobertdavis@gmail.com> writes:

>
>What is a real world example of purely resistive load supplied by AC?

An incandescent light bulb.

Re: Amperage for 5HP table saw?

<2dvnogl9mrnjpkchffg64vcumlpq3dnd0o@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5227&group=rec.woodworking#5227

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!paganini.bofh.team!news.dns-netz.com!news.freedyn.net!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!feeder1.feed.usenet.farm!feed.usenet.farm!peer03.ams4!peer.am4.highwinds-media.com!peer02.iad!feed-me.highwinds-media.com!news.highwinds-media.com!fx09.iad.POSTED!not-for-mail
From: krw...@notreal.com
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Message-ID: <2dvnogl9mrnjpkchffg64vcumlpq3dnd0o@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com> <2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com>
User-Agent: ForteAgent/8.00.32.1272
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 51
X-Complaints-To: abuse@easynews.com
Organization: Forte - www.forteinc.com
X-Complaints-Info: Please be sure to forward a copy of ALL headers otherwise we will be unable to process your complaint properly.
Date: Wed, 10 Nov 2021 12:14:36 -0500
X-Received-Bytes: 3262
 by: krw...@notreal.com - Wed, 10 Nov 2021 17:14 UTC

On Wed, 10 Nov 2021 05:22:37 -0800 (PST), Bob Davis
<wrobertdavis@gmail.com> wrote:

>On Monday, November 8, 2021 at 8:28:53 PM UTC-6, Clare Snyder wrote:
>> On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
>> <wrober...@gmail.com> wrote:
>> >On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>> >> In article <1078204646.761648@smirk>,
>> >> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>> >> > What amperage breaker does one need for a 5HP table saw on a 240V
>> >> > single phase circuit?
>> >> >
>> >> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>> >> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>> >> > (look it up in the NEC sometime), this means a 25 A breaker would be
>> >> > borderline sufficient, and that a 30A breaker should be generous.
>> >> > With a slow breaker (not a fuse), there should be no problems with the
>> >> > startup surge of the motor tripping the breaker.
>> >> Using Ohm's law this is a relatively simple question to answer...
>> >> 1 horsepower = 745.7 watts
>> >> Power (watts) = I (amperage) x E (voltage)
>> >> When you have two values for the variables in the equation you can
>> >> figure out the third.
>> >> P 3728.5 (watts 1 HP x 5)
>> >> Therefore I = --- or I = ------
>> >> E 230 volts
>> >>
>> >> 230 volts = 16.21 amps
>> >> 240 volts = 15.53 amps
>> >>
>> >> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>> >> load above 16 amps. It seems to me, that with the proper type of "slow"
>> >> breaker, you should be OK with a 20 amp breaker.
>> >>
>> >> Joe
>> >>
>> >> PS
>> >> I am not an electrician or an electrical engineer. In fact, I have
>> >> never even played one on TV.
>> >
>> >Ohm's law is for DC. It does not apply to AC.
>> Yes it does - the R just means reactance instead of resistance -
>> wheather inductive or capacitive. With resistive loads it's the same
>> as with DC - read the resistance on your ohm-meter. With "inductive
>> loads" the reactance will always be higher than the resistance (draws
>> less current)
>
>What is a real world example of purely resistive load supplied by AC?

Your oven. Water heaters, space heaters, light bulbs (sorta, though
temperature dependent).

Re: Amperage for 5HP table saw?

<j3foogh9371rq3i3vpns13gb8hc6etbkbs@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5231&group=rec.woodworking#5231

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!paganini.bofh.team!news.dns-netz.com!news.freedyn.net!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!feeder1.feed.usenet.farm!feed.usenet.farm!peer01.ams4!peer.am4.highwinds-media.com!peer02.iad!feed-me.highwinds-media.com!news.highwinds-media.com!fx08.iad.POSTED!not-for-mail
From: jclarke....@gmail.com (J. Clarke)
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Message-ID: <j3foogh9371rq3i3vpns13gb8hc6etbkbs@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com> <2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com>
User-Agent: ForteAgent/8.00.32.1272
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 50
X-Complaints-To: abuse@easynews.com
Organization: Forte - www.forteinc.com
X-Complaints-Info: Please be sure to forward a copy of ALL headers otherwise we will be unable to process your complaint properly.
Date: Wed, 10 Nov 2021 16:42:30 -0500
X-Received-Bytes: 3257
 by: J. Clarke - Wed, 10 Nov 2021 21:42 UTC

On Wed, 10 Nov 2021 05:22:37 -0800 (PST), Bob Davis
<wrobertdavis@gmail.com> wrote:

>On Monday, November 8, 2021 at 8:28:53 PM UTC-6, Clare Snyder wrote:
>> On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
>> <wrober...@gmail.com> wrote:
>> >On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>> >> In article <1078204646.761648@smirk>,
>> >> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>> >> > What amperage breaker does one need for a 5HP table saw on a 240V
>> >> > single phase circuit?
>> >> >
>> >> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>> >> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>> >> > (look it up in the NEC sometime), this means a 25 A breaker would be
>> >> > borderline sufficient, and that a 30A breaker should be generous.
>> >> > With a slow breaker (not a fuse), there should be no problems with the
>> >> > startup surge of the motor tripping the breaker.
>> >> Using Ohm's law this is a relatively simple question to answer...
>> >> 1 horsepower = 745.7 watts
>> >> Power (watts) = I (amperage) x E (voltage)
>> >> When you have two values for the variables in the equation you can
>> >> figure out the third.
>> >> P 3728.5 (watts 1 HP x 5)
>> >> Therefore I = --- or I = ------
>> >> E 230 volts
>> >>
>> >> 230 volts = 16.21 amps
>> >> 240 volts = 15.53 amps
>> >>
>> >> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>> >> load above 16 amps. It seems to me, that with the proper type of "slow"
>> >> breaker, you should be OK with a 20 amp breaker.
>> >>
>> >> Joe
>> >>
>> >> PS
>> >> I am not an electrician or an electrical engineer. In fact, I have
>> >> never even played one on TV.
>> >
>> >Ohm's law is for DC. It does not apply to AC.
>> Yes it does - the R just means reactance instead of resistance -
>> wheather inductive or capacitive. With resistive loads it's the same
>> as with DC - read the resistance on your ohm-meter. With "inductive
>> loads" the reactance will always be higher than the resistance (draws
>> less current)
>
>What is a real world example of purely resistive load supplied by AC?

I believe an oven or (non-induction) stove would come pretty close.

Re: Amperage for 5HP table saw?

<l2ioogh9464jetgav2i6mngguimn415qo7@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5232&group=rec.woodworking#5232

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!aioe.org!feeder1.feed.usenet.farm!feed.usenet.farm!tr3.eu1.usenetexpress.com!feeder.usenetexpress.com!tr1.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!buffer1.nntp.dca1.giganews.com!buffer2.nntp.dca1.giganews.com!news.giganews.com.POSTED!not-for-mail
NNTP-Posting-Date: Wed, 10 Nov 2021 16:33:54 -0600
From: markrm...@hotmail.com (Markem618)
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Date: Wed, 10 Nov 2021 16:33:54 -0600
Message-ID: <l2ioogh9464jetgav2i6mngguimn415qo7@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com> <2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com> <j3foogh9371rq3i3vpns13gb8hc6etbkbs@4ax.com>
User-Agent: ForteAgent/8.00.32.1272
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 56
X-Usenet-Provider: http://www.giganews.com
X-Trace: sv3-oY8junjJwvhBqxYCAF75UX0Eq10Vqf8wx1jWvF7n2nz4Ke6EeetL7oM9ew6IZqTw6GQs7rTaxUVnTCp!mrkrDPknedXsdVbdCMGKJdLd6gwXeSSkVCIehPn06z0UG2MBqayW4EfMWfOqrkKhNN/1nQ==
X-Complaints-To: abuse@giganews.com
X-DMCA-Notifications: http://www.giganews.com/info/dmca.html
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
X-Postfilter: 1.3.40
X-Original-Bytes: 3805
 by: Markem618 - Wed, 10 Nov 2021 22:33 UTC

On Wed, 10 Nov 2021 16:42:30 -0500, J. Clarke
<jclarke.873638@gmail.com> wrote:

>On Wed, 10 Nov 2021 05:22:37 -0800 (PST), Bob Davis
><wrobertdavis@gmail.com> wrote:
>
>>On Monday, November 8, 2021 at 8:28:53 PM UTC-6, Clare Snyder wrote:
>>> On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
>>> <wrober...@gmail.com> wrote:
>>> >On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>>> >> In article <1078204646.761648@smirk>,
>>> >> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>>> >> > What amperage breaker does one need for a 5HP table saw on a 240V
>>> >> > single phase circuit?
>>> >> >
>>> >> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>>> >> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>>> >> > (look it up in the NEC sometime), this means a 25 A breaker would be
>>> >> > borderline sufficient, and that a 30A breaker should be generous.
>>> >> > With a slow breaker (not a fuse), there should be no problems with the
>>> >> > startup surge of the motor tripping the breaker.
>>> >> Using Ohm's law this is a relatively simple question to answer...
>>> >> 1 horsepower = 745.7 watts
>>> >> Power (watts) = I (amperage) x E (voltage)
>>> >> When you have two values for the variables in the equation you can
>>> >> figure out the third.
>>> >> P 3728.5 (watts 1 HP x 5)
>>> >> Therefore I = --- or I = ------
>>> >> E 230 volts
>>> >>
>>> >> 230 volts = 16.21 amps
>>> >> 240 volts = 15.53 amps
>>> >>
>>> >> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>>> >> load above 16 amps. It seems to me, that with the proper type of "slow"
>>> >> breaker, you should be OK with a 20 amp breaker.
>>> >>
>>> >> Joe
>>> >>
>>> >> PS
>>> >> I am not an electrician or an electrical engineer. In fact, I have
>>> >> never even played one on TV.
>>> >
>>> >Ohm's law is for DC. It does not apply to AC.
>>> Yes it does - the R just means reactance instead of resistance -
>>> wheather inductive or capacitive. With resistive loads it's the same
>>> as with DC - read the resistance on your ohm-meter. With "inductive
>>> loads" the reactance will always be higher than the resistance (draws
>>> less current)
>>
>>What is a real world example of purely resistive load supplied by AC?
>
>I believe an oven or (non-induction) stove would come pretty close.

Electric baseboards, electric resistor elements in a heat pump system
for when the temp is to cold.

Re: Amperage for 5HP table saw?

<2ae10c5b-b966-4b28-b492-fde832bfa582n@googlegroups.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5233&group=rec.woodworking#5233

  copy link   Newsgroups: rec.woodworking
X-Received: by 2002:a05:620a:d96:: with SMTP id q22mr2700387qkl.219.1636586945000;
Wed, 10 Nov 2021 15:29:05 -0800 (PST)
X-Received: by 2002:a05:6808:220f:: with SMTP id bd15mr10532557oib.73.1636586944634;
Wed, 10 Nov 2021 15:29:04 -0800 (PST)
Path: i2pn2.org!i2pn.org!weretis.net!feeder8.news.weretis.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: rec.woodworking
Date: Wed, 10 Nov 2021 15:29:04 -0800 (PST)
In-Reply-To: <2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com>
Injection-Info: google-groups.googlegroups.com; posting-host=73.55.151.166; posting-account=Pu0UeAoAAABPhKXXMI9Wp2n-KFrwpmWm
NNTP-Posting-Host: 73.55.151.166
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com>
<2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com>
<2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <2ae10c5b-b966-4b28-b492-fde832bfa582n@googlegroups.com>
Subject: Re: Amperage for 5HP table saw?
From: wrobertd...@gmail.com (Bob Davis)
Injection-Date: Wed, 10 Nov 2021 23:29:04 +0000
Content-Type: text/plain; charset="UTF-8"
 by: Bob Davis - Wed, 10 Nov 2021 23:29 UTC

On Wednesday, November 10, 2021 at 7:22:39 AM UTC-6, Bob Davis wrote:
> On Monday, November 8, 2021 at 8:28:53 PM UTC-6, Clare Snyder wrote:
> > On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
> > <wrober...@gmail.com> wrote:
> > >On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
> > >> In article <1078204646.761648@smirk>,
> > >> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
> > >> > What amperage breaker does one need for a 5HP table saw on a 240V
> > >> > single phase circuit?
> > >> >
> > >> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
> > >> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
> > >> > (look it up in the NEC sometime), this means a 25 A breaker would be
> > >> > borderline sufficient, and that a 30A breaker should be generous.
> > >> > With a slow breaker (not a fuse), there should be no problems with the
> > >> > startup surge of the motor tripping the breaker.
> > >> Using Ohm's law this is a relatively simple question to answer...
> > >> 1 horsepower = 745.7 watts
> > >> Power (watts) = I (amperage) x E (voltage)
> > >> When you have two values for the variables in the equation you can
> > >> figure out the third.
> > >> P 3728.5 (watts 1 HP x 5)
> > >> Therefore I = --- or I = ------
> > >> E 230 volts
> > >>
> > >> 230 volts = 16.21 amps
> > >> 240 volts = 15.53 amps
> > >>
> > >> Using the "80% rule", a 20 amp breaker should not exceed a continuous
> > >> load above 16 amps. It seems to me, that with the proper type of "slow"
> > >> breaker, you should be OK with a 20 amp breaker.
> > >>
> > >> Joe
> > >>
> > >> PS
> > >> I am not an electrician or an electrical engineer. In fact, I have
> > >> never even played one on TV.
> > >
> > >Ohm's law is for DC. It does not apply to AC.
> > Yes it does - the R just means reactance instead of resistance -
> > wheather inductive or capacitive. With resistive loads it's the same
> > as with DC - read the resistance on your ohm-meter. With "inductive
> > loads" the reactance will always be higher than the resistance (draws
> > less current)
> What is a real world example of purely resistive load supplied by AC?

Thanks to everyone who responded.

Re: Amperage for 5HP table saw?

<hcapogptn57272pr243ordun0mre794fr9@4ax.com>

  copy mid

https://www.novabbs.com/interests/article-flat.php?id=5241&group=rec.woodworking#5241

  copy link   Newsgroups: rec.woodworking
Path: i2pn2.org!i2pn.org!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: cla...@snyder.on.ca (Clare Snyder)
Newsgroups: rec.woodworking
Subject: Re: Amperage for 5HP table saw?
Date: Thu, 11 Nov 2021 00:30:25 -0500
Organization: A noiseless patient Spider
Lines: 58
Message-ID: <hcapogptn57272pr243ordun0mre794fr9@4ax.com>
References: <1078204646.761648@smirk> <020320040720322031%comfortable@work.com> <2dda5020-357f-4d89-a43f-94b48e712a45n@googlegroups.com> <q1njog92e9ev68jrhh4bmhmuemp53ecnao@4ax.com> <2bcc2e60-e5f1-4419-bd5f-d6998a5628b9n@googlegroups.com> <j3foogh9371rq3i3vpns13gb8hc6etbkbs@4ax.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Injection-Info: reader02.eternal-september.org; posting-host="2ab394befed92eed24d80ae1108b5f25";
logging-data="2509"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19a0GnjZKu5vkyRoPS8WZZ5"
User-Agent: ForteAgent/8.00.32.1272
Cancel-Lock: sha1:BUAGfkMlUR0u+gAP0gDeJtfY24c=
 by: Clare Snyder - Thu, 11 Nov 2021 05:30 UTC

On Wed, 10 Nov 2021 16:42:30 -0500, J. Clarke
<jclarke.873638@gmail.com> wrote:

>On Wed, 10 Nov 2021 05:22:37 -0800 (PST), Bob Davis
><wrobertdavis@gmail.com> wrote:
>
>>On Monday, November 8, 2021 at 8:28:53 PM UTC-6, Clare Snyder wrote:
>>> On Mon, 8 Nov 2021 16:07:24 -0800 (PST), Bob Davis
>>> <wrober...@gmail.com> wrote:
>>> >On Tuesday, March 2, 2004 at 6:20:32 AM UTC-6, Joe McDonald wrote:
>>> >> In article <1078204646.761648@smirk>,
>>> >> <_firstname_@lr_dot_los-gatos_dot_ca.us> wrote:
>>> >> > What amperage breaker does one need for a 5HP table saw on a 240V
>>> >> > single phase circuit?
>>> >> >
>>> >> > My logic: Typically, single phase 5HP 240V (or 230V) motors are rated
>>> >> > at 19.8 or 20 A. Given that a circuit is supposed to be loaded 80%
>>> >> > (look it up in the NEC sometime), this means a 25 A breaker would be
>>> >> > borderline sufficient, and that a 30A breaker should be generous.
>>> >> > With a slow breaker (not a fuse), there should be no problems with the
>>> >> > startup surge of the motor tripping the breaker.
>>> >> Using Ohm's law this is a relatively simple question to answer...
>>> >> 1 horsepower = 745.7 watts
>>> >> Power (watts) = I (amperage) x E (voltage)
>>> >> When you have two values for the variables in the equation you can
>>> >> figure out the third.
>>> >> P 3728.5 (watts 1 HP x 5)
>>> >> Therefore I = --- or I = ------
>>> >> E 230 volts
>>> >>
>>> >> 230 volts = 16.21 amps
>>> >> 240 volts = 15.53 amps
>>> >>
>>> >> Using the "80% rule", a 20 amp breaker should not exceed a continuous
>>> >> load above 16 amps. It seems to me, that with the proper type of "slow"
>>> >> breaker, you should be OK with a 20 amp breaker.
>>> >>
>>> >> Joe
>>> >>
>>> >> PS
>>> >> I am not an electrician or an electrical engineer. In fact, I have
>>> >> never even played one on TV.
>>> >
>>> >Ohm's law is for DC. It does not apply to AC.
>>> Yes it does - the R just means reactance instead of resistance -
>>> wheather inductive or capacitive. With resistive loads it's the same
>>> as with DC - read the resistance on your ohm-meter. With "inductive
>>> loads" the reactance will always be higher than the resistance (draws
>>> less current)
>>
>>What is a real world example of purely resistive load supplied by AC?
>
>I believe an oven or (non-induction) stove would come pretty close.
99% close enough? A baseboard heater or any calrod heater, an
incandescent lamp. So that covers an electric water heater - and
heat-chaser cables - and electric in-floor heating cables - even an
electric blanket. (Yes there IS a small inductive element if it has a
coiled heat element - but virtually none if carbon fiber)

1
server_pubkey.txt

rocksolid light 0.9.8
clearnet tor