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Topic: Foretravel installed fan in bedroom, 2001, 320 ? (Read 703 times) previous topic - next topic

Foretravel installed fan in bedroom, 2001, 320 ?

I give up, how many speeds do they have,  3, 4, maybe 5 or 6 ? No idea, but more than I would guess, from very fast to slow where it is easy to coubt the blades, not the rpm. Pull the chain makes a difference, but it keeps going, just slower and slower, now lost count.
Played earlier, but forget.
Last night, turned on slowly, this morning pulled chain again, this Pm, its still gooing, pull chain again, slows but no stop. Pull again, grab blade, it stopped. :o
Dave M

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #1 –
I have factory fan and it is a 3 speed. Goes pretty fast on slow and goes faster as you pull the chain. It does take awhile for it to slow down and stop.
Jon Ohman
2001 U320 36'
Build #5809

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #2 –
Quote from: sam7 –
I have factory fan and it is a 3 speed. Goes pretty fast on slow and goes faster as you pull the chain. It does take awhile for it to slow down and stop.
Dave, My ceiling fan works this way also, 3 speeds.
The selected media item is not currently available.Barry BEAM #16014
2003 U320 40' AGDS
Beamalarm, Foretravel technical help and specifications
"Whatever the mind can conceive and believe, it can achieve"

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #3 –
Mine starts on high, then goes lower with each chain pull.  three speed. 
Norm H
Norm H.
2002 U320 3602
PBDS
Build # 5941
MC# 16699


1997 Gulfstream Tourmaster, Cummins 8.3
2000 Country Coach Magna, Cat C-10
1998 Foretravel U295, Cummins 8.3

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #4 –
Per the Experts, My fan clearly is fouled up, it takes 4 pulls once it is started to be able to stop it, at 3rd pull it turns very slowly, maybe 30-40 rpm, 4th pull it can be stopped.
Love weird things.
Thanks for the Opinions
Dave M

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #5 –
Dave M, that is the same way my foretravel installed fan in our 03 u320 works, seems weird to me but just my opinion
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #6 –
 Why do most fans start on the highest speed vs. the slowest speed?
 
    • When any motor is started, it presents a low impedance to the electrical supply (think of it as resistance to current flow) and a large current flows (generally 6 to 8 times normal current flow).  This usually lasts for a very short time because as the motor turns, it self-generates a current which opposes the incoming current.  The faster the motor turns, the greater the reverse current becomes (back electro-motive force - back e.m.f).  If you start a domestic fan on a slow speed it takes much longer for the motor to produce enough back e.m.f to limit the current, therefore the motor experiences high current and high heating of the armature and windings for a longer time and the useful lifetime of the fan is decreased. 
       
    • So, acceleration is key. Accelerate quickly, build e.m.f.,  limit the inrush current time and minimize the motor internal heating. 
       
    • Also, consider that small fan motors are not robust and produce very low torque (both running torque and the even smaller starting torque).  Trying to start on a slow speed may not produce enough starting torque to overcome the starting friction.  If this happens, the motor may sit at full inrush current, in a locked-rotor condition, until it burns through a winding, shorts and trips the supply breaker or fuse, hopefully without starting a fire.
       
    • Conversely, many small fan motors may appear to continue running when deenergized.  They may have such a small running friction value that, once their starting friction is overcome, their resistance to turning may be easily overcome by small air currents acting on the large torque-producing blades of the fan.  As long as tiny air currents (including thermal convection) persist, a deenergized fan may appear to run forever.
       
    • Besides e.m.f., there are other ways to limit the flow of a fan's starting current, but they add to the cost of a fan.  More costly current limiting designs are used in large motor industrial applications and in more expensive fans.  Another place you see this done is in portable electric drills with variable speed controllers.  Drill motors are far more robust (weigh the two motors...fan and drill) and are designed to start slowly against a high percentage of their maximum-rated applied load while simultaneously limiting the drill motor starting current and the armature heating.
Happy New Year, stay warm,
Neal
 
The selected media item is not currently available.
Neal (& Brenda) Pillsbury
'02 U320 SPEC, 4200, DGFE, Build #5984
'04 Gold Wing
'07 Featherlite 24'
'14 Jeep Grand Cherokee Summit
MC #14494
Exeter, NH & LaBelle FL
Quality makes the Heart Soar long after Price is Forgotten

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #7 –
Neal,
Great review, can clearly see I need to investigate the LRA, then the running load, each speed.  I am impressed with the weight of the rotating mass, the smoothness of the bearings and feel the assembly is of very good design & quality.  It has been riding along over 105,000 miles and still works great.
 One day when I get bored enough it will happen and will report the findings including the voltage drop.
Dave M

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #8 –
Quote
Why do most fans start on the highest speed vs. the slowest speed?
Hey, Neal, thanks. I always wondered about that!
jor
93 225
95 300
97 270
99 320

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #9 –
I liked that explanation of the operation of the fan, makes sense now
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins
 

Re: Foretravel installed fan in bedroom, 2001, 320 ?

Reply #10 –
Great explanation. 
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon