OK, frankly, --having taken my fan completely down to refurb it, and having
inspected all of it's bits closely. --this discussion was driving me a bit
bonkers. So I went to the garage and took my spare beat up fan and hooked it
up both ways.....
.......Not truly what I would call a centrifugal pump, the vaned "birdcage"
will in fact, scoop air in the wrong direction when the rotation is backward.
Hooked up right way round, there is a fairly strong flow of air out the molded
port on the body of the fan. Hooked up wrong way round, there is no flow out
the normal port, and a weak flow of air out the metal flanged port on the
center of the fan opposite the fan motor....
So this one at least, can run backward, and blow air backward, somewhat.
Isn't science FUN? ---Mr. Wizard
David W. Jones
'62 Mk II BT7 tricarb
Cumberland, RI USA
----- Original Message -----
From: John Miller
To: Healeys list
Sent: Thursday, September 15, 2005 7:33 AM
Subject: Re: heater fan sucks
Earl Kagna wrote:
>Due respect Rich, the Healey heater blower motor is a permanent magnet
>motor - doesn't care about polarity. I have converted at least a half
dozen
>Healeys to NEG ground, including my present two, without interchanging the
>blower motor wires - they've all continued to move air in the right
>direction.
>
>
Earl, there's been a misunderstanding somewhere -- permanent magnet DC
motors do reverse rotation with polarity. As has been pointed, because
it's a centrifugal blower, it will move air regardless of the direction
of motor rotation, HOWEVER, it will move air ever so much better when
the rotation is in the correct direction.
--
John Miller
Hotlanta
|