Yesterday's Tractor Co. Shop Now
   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
Classified Ads
Photo Ads
Tractor Parts

Discussion Forums
Project Journals
Tractor Town
Your Stories
Show & Pull Guide
Events Calendar
Hauling Schedule

Tractor Photos
Implement Photos
Vintage Photos
Help Identify
Parts & Pieces
Stuck & Troubled
Vintage Ads
Community Album
Photo Ad Archives

Research & Info
Tractor Registry
Tip of the Day
Safety Cartoons
Tractor Values
Serial Numbers
Tune-Up Guide
Paint Codes
List Prices
Production Nbrs
Tune-Up Specs
Torque Values
3-Point Specs

Tractor Games
Just For Kids
Virtual Show
Museum Guide
Memorial Page
Feedback Form

Yesterday's Tractors Facebook Page

Related Sites
Tractor Shed
Ford 8N/9N Club
Today's Tractors
Garden Tractors
Classic Trucks
Kountry Life
Tool Talk Discussion Forum

Re: JohnT?

[Show Entire Topic]  

Welcome Guest, Log in or Register
Author  [Modern View]
George Marsh

12-16-2013 07:05:20

Report to Moderator

Hope momma is doing well. Before my mom died at 88, I made many trips to Florida to watch her. It was a blessing she passed on Easter Sunday 3 years. No one should have to live with cancer and all the pain she went through.

Follow up question. I'll try to make it simple.

My 3/4 hp water pump on 110v will use about 12 amps. I put 200 MFD's in parallel with motor and dropped the current to 9 amps. Measured PF, it's 0.99. The motor still draws 12 amps, the line current going to motor is 9 amps.

It's my understanding that with or without the cap bank. My electric meter only sees the 9 amps and not the 12 amps. Is that correct?

There will be a follow up question.

"Curious George"

[Log in to Reply]   [No Email]
John T

12-16-2013 14:22:45

Report to Moderator
 Re: JohnT? in reply to George Marsh, 12-16-2013 07:05:20  
Hey George, I, as you know, meant no offense with the "curious George" nickname. Heck I'm curious as a cat myself and seems my kids years ago watched a cartoon about some curious George, character, but I'm not sure.

Not having your meter or any specs or anything at all, its still my "best guess" you're correct, it sees the amperage which would be that if you had a unity one power factor, which means it does NOT see the vector sum of the resistive current component flow PLUS the Inductive (out of phase if not corrected) component. The electric company watt hour meter doesn't take power factor into consideration far as I know (44 years ago Duncan Meter Co gave a talk in our EE school but Ive slept since then) HOWEVER at the place I worked they still monitored Power Factor (even if meter didn't show) and charged us a huge penalty if we were off Unity by too much........

Tell you what, my friend the good Buick man (unlike long retired me) is very active in this business and knows this power factor stuff better then me, but its still my guess your meter DOES NOT SEE or take power factor or out of unity power factor current into consideration. See what he and the other more current in the practice sparkies have to say NO WARRANTY on my best guesses about how your particular meter works.

See, Im as curious as you are and always willing to learn.......

A rusty OLD John T

[Log in to Reply]  [No Email]

12-16-2013 17:06:38

Report to Moderator
 Re: JohnT? in reply to John T, 12-16-2013 14:22:45  
John, I know power engineering was your speciality, and I've never worked in the field. But I'm fairly sure kwh meters measure actual power, not volt-amps. The traditional mechanical meters have both voltage and current windings; if current and voltage are out of phase, that will be reflected in the number of watt-hours recorded by the meter. I think the newer "smart" meters can record not just kwh, but average current, voltage, power factor and a bunch of other stuff.

Of course, utilities can and do penalize customers with low power factors. Look at it this way: if the power company could charge based on volt-amps rather than watts, they wouldn't be too concerned about customers with poor power factors.

[Log in to Reply]  [No Email]
John T

12-16-2013 18:04:48

Report to Moderator
 Re: JohnT? in reply to MarkB_MI, 12-16-2013 17:06:38  
Hey there Mark, Actually AC Power Distribution was more my specialty and while I worked a lot with Power Factor and Power Factor Correction, Im very rusty in that area as well as the types of modern or "smart" KWH Meters etc. Like I used to tell my kids "Old dad knows some things but NOT everything" HOWEVER the things I DID SAY about what PF is and its definition etc is I believe accurate.........I may have to break down and refresh myself in this area but Im too lazy and old for that. The "stuff" I do know I'm glad to share and help people with as you well know.

John T

[Log in to Reply]  [No Email]
George Marsh

12-16-2013 14:42:16

Report to Moderator
 Re: JohnT? in reply to John T, 12-16-2013 14:22:45  

No offense taken.

So, if I got things right in my head, with or without caps, the motor uses the same current and generates the same heat.

The only thing that benefits is the circuit breaker in the load center is seeing less amps and there is less I squared loss in the wire going to the motor.

What about a generator? Is it better for a genny to PF?


[Log in to Reply]  [No Email]
John T

12-16-2013 15:27:35

Report to Moderator
 Re: JohnT? in reply to George Marsh, 12-16-2013 14:42:16  
"So, if I got things right in my head, with or without caps, the motor uses the same current and generates the same heat."

I cant say that's exactly right, but its hard to explain and I'm way too lazy to dust off my books lol. Here's what I will say, however. If the PF is unity meaning, the current isn't leading or lagging the voltage, its in phase, the vector sum of the resistive current component and reactive (L/C) current component is the same as the resistive ONLY i.e. C canceled out the L. However, if the PF is less then unity, the current is the vector sum of the 2 out of phase components (R + L/C) even though a meter doesn't take that into account, its watts NOT Volt Amps.

"What about a generator? Is it better for a genny to PF?"

The utility or a genset generates a sine wave and it has to "work" less if the load is unity PF. If the PF is lousy the genset or utility is actually having to produce the in plus out of phase current components (vector sum) and that's why we were charged a penalty for a lousy PF even though our watt hour meters registered the same

HEY GEORGE IM RUNNIN OUTA SMARTS ON THIS PF STUFF this is my best recollection but certainly not warranted correct. When I believe an answer is correct I just state it, but Im NOT sure on this PF stuff, its been too long, dont take any drastic steps based on the above, consult someone more current in the trade whose not been retired over 20 years ........

Sorry, but that's all I got

John T

[Log in to Reply]  [No Email]
George Marsh

12-16-2013 19:16:24

Report to Moderator
 Re: JohnT? in reply to John T, 12-16-2013 15:27:35  
thanks JohnT,
I am very familar with vectors, series and parallel tank circuits, XL, Xc, R, Z, all the equations in electronics. Never really applied them to motors.

What I'm not 100% sure of, but going to take a guess an educated guess on what you call unity(powerfactor).

When the phase angle between the vector sum and R is zero, the cos of zero is one and the Power Factor is 1, unity.

So, if you were to find the phase angle then the cosine of that angle transulates to the power factor. example. The phase angle is 45 degrees, the cosine of 45 is .707. Therefore you would say the power factor is .707. As the phase angle approaches 90 degrees, the power factor approaches 0. As phase angle approaches zero, power factor approaches 1.

If you can follow this chatter, good luck.

Yes. I have too much time on my hands.

So, is the cos of phase angle = power factor.

Inverse cosine of power factor = phase angle.

I'm kinda of rusty too. Only been retired 10 years. I pitched all my books.


[Log in to Reply]  [No Email]
John T

12-17-2013 03:45:52

Report to Moderator
 Re: JohnT? in reply to George Marsh, 12-16-2013 19:16:24  
"So, is the cos of phase angle = power factor. "

YOU GOT IT.........And if they are in phase the angle is zero and the cosine of zero is one...

Fun huh

John T

[Log in to Reply]  [No Email]
George Marsh

12-17-2013 06:11:34

Report to Moderator
 Re: JohnT? in reply to John T, 12-17-2013 03:45:52  
Don't think I ever read that any place. Why do some try to make it so complicated?

[Log in to Reply]  [No Email]
[Show Entire Topic]     [Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:

Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

Home  |  Forums

Copyright © 1997-2018 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters