Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-05-2007, 04:26 PM   #29
Rivet Master
 
Pop Rivet's Avatar
 
1990 25' Airstream 250
Altoona , Georgia
Join Date: Aug 2005
Posts: 805
Images: 5
the amount of current the fan motor draws is a function of how much air the fan is moving and at what air pressure. If you are measuring the current with the fan removed from the furnace and distribution system, the current (amps) should read very low. If the fan is installed in the system and the air outlets are blocked, the current will read low. If the fan is running backwards, the current will read low.
__________________

__________________
Pop Rivet is offline   Reply With Quote
Old 02-05-2007, 06:52 PM   #30
2 Rivet Member
 
Join Date: Apr 2005
Posts: 52
It sounds like the problem has been solved. Thanks again to everybody for their help and advice. I would be lost without this great forum and community.

Thanks again,

Greg
__________________

__________________
85Sovereign is offline   Reply With Quote
Old 02-05-2007, 07:03 PM   #31
INSANITY CENTRAL
 
doorgunner's Avatar
 
1986 32' Excella
2014 Interstate Ext. Coach
Citrus Heights , California
Join Date: Aug 2006
Posts: 2,105
Images: 35
Greg, I'm curious-m could you reinstall the the old motor with the gravel in the bearings and take a reading again. Just wondering how much the drag would effect the amp draw!! Glad you got it repaired
__________________


www.popasmoke.com




Proud Appellation American





Vine View Heights is now closed.

YETI ( 65 Quart )

IGLOO (Ice Cube, 50 Quart )
doorgunner is offline   Reply With Quote
Old 02-10-2007, 08:17 AM   #32
2 Rivet Member
 
Join Date: Apr 2005
Posts: 52
That was an idea I had as well. But, I let one of my knuckle headed friends open the motor up. He beat on it with a screwdriver and some little springs fell out that I could never get back in around the brushes. Needless to say I destroyed these little springs when I thought I had it back together correctly. I even found a source for replacement bearings here in OKC. But, I did not pursue the new bearings since I could not find any new springs. So, I think it would be a good motor if I could just find those little springs again. Anybody know where I could get a rebuild kit?

Greg
__________________
85Sovereign is offline   Reply With Quote
Old 02-20-2007, 06:38 AM   #33
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,282
Quote:
Originally Posted by David Alan
the amount of current the fan motor draws is a function of how much air the fan is moving and at what air pressure. If you are measuring the current with the fan removed from the furnace and distribution system, the current (amps) should read very low. If the fan is installed in the system and the air outlets are blocked, the current will read low. If the fan is running backwards, the current will read low.
David,

It has been my experience that a fan running in a closed system with the air outlets blocked will have a HIGHER amperage reading due to the back pressure created by the lack of outlets, causing it to work harder while attempting to move the air. The statement about the free air reading is correct.

The same goes for A/C compressors. We use amp readings to determine if the compressor is working properly or if the sealed refrigerant system has had a leak, in which case the system has little or no back pressure and shows a much lower amp draw than the operational rating.
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 02-20-2007, 07:40 AM   #34
Rivet Master
 
Pop Rivet's Avatar
 
1990 25' Airstream 250
Altoona , Georgia
Join Date: Aug 2005
Posts: 805
Images: 5
Quote:
Originally Posted by lewster
David,

It has been my experience that a fan running in a closed system with the air outlets blocked will have a HIGHER amperage reading due to the back pressure created by the lack of outlets, causing it to work harder while attempting to move the air. The statement about the free air reading is correct.

The same goes for A/C compressors. We use amp readings to determine if the compressor is working properly or if the sealed refrigerant system has had a leak, in which case the system has little or no back pressure and shows a much lower amp draw than the operational rating.
Hmm - I can tell you this - I enjoy your posts and like your thinking but regardless of your experience. work is a function of force x distance and if you are not moving the air, you are not doing any work. Power is the rate work is being done - power equals work/ time. Watts is the term used to define electrical power and is a function of volts x amps. Years ago I did air balences on large HVAC systems and I can assure you that as the air flow dampers were opened up and the air movers moved more air, the current readings went up. One of the controlling factors was the motor current as you could overload the driver by moving too much air.

I look forward to meeting you at Springstream.
__________________
Pop Rivet is offline   Reply With Quote
Old 02-20-2007, 07:57 AM   #35
Rivet Master
 
fastrob's Avatar
 
1976 25' Tradewind
. , AZ to Maine
Join Date: Sep 2004
Posts: 545
Current Thoughts

Please explain: Current, Voltage and Amperage
I thought current was the flow of electrons. Voltage is the size of the pipe carrying the electrons and Amperage is the amount of pressure behind the pipe, using the water pipe analogy.
Is that correct?
So, if there was no back pressure on the heater fan the current would flow higher, within the limits of the wire or pipe? The amperage would be lower?
If there was back pressure on the fan causing the fan to work harder the current flow would be lower but the amperage or backpressure would be higher due to the increased work by the fan?
I know it is not voltage, it is amperage that kills you.

Rob
__________________
fastrob is offline   Reply With Quote
Old 02-20-2007, 08:14 AM   #36
Rivet Master
 
Pop Rivet's Avatar
 
1990 25' Airstream 250
Altoona , Georgia
Join Date: Aug 2005
Posts: 805
Images: 5
Quote:
Originally Posted by fastrob
Please explain: Current, Voltage and Amperage
I thought current was the flow of electrons. Voltage is the size of the pipe carrying the electrons and Amperage is the amount of pressure behind the pipe, using the water pipe analogy.
Is that correct?
So, if there was no back pressure on the heater fan the current would flow higher, within the limits of the wire or pipe? The amperage would be lower?
If there was back pressure on the fan causing the fan to work harder the current flow would be lower but the amperage or backpressure would be higher due to the increased work by the fan?
I know it is not voltage, it is amperage that kills you.

Rob
You are close - Voltage is electrical pressure. Current is the flow of electrons.
Amperage is the measure of current. E (Voltage) = I (current) x R (resistance) so e= IR, I= E/R, R= E/I. Watts or power equals volts x amps.
If you have a electric pump with a discharge valve and put an amp meter on the motor cord, As you open the discharge valve, the motor amps will increase. Some large pumps have a interlock that requires the discharge valve to be shut during motor starts to prevent motor overload.
__________________

__________________
Pop Rivet is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hot water Heater DClark Water Heaters, Filters & Pumps 15 08-25-2017 03:35 AM
Water Heater Craig 1978- 1979 Excella 500 7 10-01-2007 06:16 PM
Repair or Replace Original Bowen Water Heater? Andy R Water Heaters, Filters & Pumps 8 11-16-2005 04:51 PM
wiring - water heater Craig Electrical - Systems, Generators, Batteries & Solar 12 10-02-2002 06:03 AM
Water Heater shell frame BobbyW Water Heaters, Filters & Pumps 0 04-29-2002 11:21 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:41 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.