Maker Pro
Maker Pro

Fan speed problem

W

Wayne Tiffany

Jan 1, 1970
0
I have a room fan that now has a problem (this is a fan with 3 speed
switches and one cap.) When I turn it on, it will speed up for about 4
seconds and then slow down to just barely running. My first thought was
lubrication, so I addressed that. So then I suspected the capacitor - it's
a 3mf cap and tested at 3.178. I also disconnected it and tried a new one -
no change. Then I measured the resistance of the 3 windings. They are
231.8 low, 192.6 med, 116.3 high. I also didn't find any shorted to the
frame. The model is Aries CH-16SF, UL listed 49L2, distributed by Dollar
General.

I know that sometimes it's easier to buy a new one, but I'm baffled by what
could have changed to produce these symptoms and would like to understand
it. My best guess is that the windings shorted somewhere out in the middle,
enough to destroy the magnetic field, but not enough to heat up enough to
feel it. Any thoughts?

WT
 
W

Wayne Tiffany

Jan 1, 1970
0
I tried jumping directly to the winding leads after the switches - no
difference. I didn't try a new cord, however, I think it would be quite
unlikely to have a condition other than a break, in which case I would then
see intermittent operation.

WT
 
M

Mike Berger

Jan 1, 1970
0
Have you tried Dollar General's tech support?
 
W

Wayne Tiffany

Jan 1, 1970
0
Didn't know they had one - I can't imagine them supporting something like
this.

WT
 
L

lcoe

Jan 1, 1970
0
My guess would be that if it really isn't mechanical, something is
shorting or opening once it starts running.

a current meter would be useful, too hi=shorted winding, too low=bad
connection/connector. does the motor act like it's drawing current,
like w/hum? --Loren
 
W

Wayne Tiffany

Jan 1, 1970
0
Good thought - I'll have to measure the current draw tonight. However, what
I remember, is that it sounds and feels like not enough current. I don't
remember a lot of hum, but something there that tells me it's trying to do
something. What it really feels like is the cap is bad - current draw, but
not in the correct phase. However, I tried that. I'll check tonight.

WT
 
I

Ian Stirling

Jan 1, 1970
0
lcoe said:
a current meter would be useful, too hi=shorted winding, too low=bad
connection/connector. does the motor act like it's drawing current,
like w/hum? --Loren

For AC circuits especially, a loudspeaker (in a completely fingerproof
insulated box) in parallel with a .1 ohm resistor, in series with one
of the wires may be of use.

You can easily hear current changes, plus it's cheap.
 
W

Wayne Tiffany

Jan 1, 1970
0
My lubrication method was to take out the rotor, clean any hard, gunky,
messy, whatever from all of the surfaces, lube the bushing, spacer washers,
and the rotor shaft. Then reassemble. So, yes, I got both ends. Good
thought, though. I can spin it by hand and it spins very freely.

I measured the current draw last night. Low-.30 amps, Med - .35 amps,
High - .50 amps. Doesn't seem excessive and seems to be in line for the 3
speeds. Still perplexing.

WT
 
T

t.hoehler

Jan 1, 1970
0
My lubrication method was to take out the rotor, clean any hard, gunky,
messy, whatever from all of the surfaces, lube the bushing, spacer washers,
and the rotor shaft. Then reassemble. So, yes, I got both ends. Good
thought, though. I can spin it by hand and it spins very freely.

I measured the current draw last night. Low-.30 amps, Med - .35 amps,
High - .50 amps. Doesn't seem excessive and seems to be in line for the 3
speeds. Still perplexing.

Just a guess, maybe the cap is breaking down, maybe opening up? You can pick
up ceiling fan run caps at Home Depot cheap. Might throw a few bucks at it
this way, see what happens. I once had an Akai tape machine whose capstan
motor would slow down to almost nothing after a few minutes of running,
turned out to be a bad motor cap.
Let us know.
Regards,
Tom
 
W

Wayne Tiffany

Jan 1, 1970
0
Tried that first - checked the old one and also a new one on it. Even tried
changing the value to see what would happen. No change.

WT
 
L

lcoe

Jan 1, 1970
0
Wayne Tiffany said:
Tried that first - checked the old one and also a new one on it. Even tried
changing the value to see what would happen. No change.
WT

from your responses, it seems you have indeed given this a genuine effort.
my only other remark is that i was skunked by a ceiling fan, older, and
had to buy new. iirc, the problem was shaft wear/balance. in this case
the symptom was slow speed _and_ noise. i didn't have a reason to believe
the fan blades had been bent and decided the shaft wore enough to allow
some lateral or axial play that set up the vibration which then slowed
the fan. ymmv, this was 40yrs ago, on a fan that was 40 yrs old at that
time. --Loren
 
W

Wayne Tiffany

Jan 1, 1970
0
No noticeable shaft wear. I know what you mean as I also had a fan one time
that the bearing turned in the housing until it got loose enough for the
rotor to drag. Not here.

This has been a perplexing one, and I think probably a dead end. However,
it's an interesting thought challenge. I guess the last action before the
trash is tear apart the windings, thereby destroying the motor, but maybe
spotting something. You know the old adage - never throw away a machine
without first taking it apart.

WT
 
L

lcoe

Jan 1, 1970
0
Wayne Tiffany said:
No noticeable shaft wear. I know what you mean as I also had a fan one time
that the bearing turned in the housing until it got loose enough for the
rotor to drag. Not here.
This has been a perplexing one, and I think probably a dead end. However,
it's an interesting thought challenge. I guess the last action before the
trash is tear apart the windings, thereby destroying the motor, but maybe
spotting something. You know the old adage - never throw away a machine
without first taking it apart. > WT

motors are a special case, wrt to repair by amateurs, even die-hards like
you (and me). very careful and lengthy examination and testing never did
show me what went wrong with an 89Ford Escort starter that "failed" while
the unit sat idle for 2yrs.

i took to the parts house and it was "dragging", pulling way to much
juice. took it and the replacement home, new unit turns the engine
just fine. disassembled, cleaned, lubed, metered for shorts/opens,
re-installed, sameo-sameo. and it still pulled excess current on the
tester when i took it back for a core refund. skunked again. --Loren
 
Top