Re: Central Vac overload

["Robert Green" <robert_green1963@xxxxxxxxx>]

"George" <george@xxxxxxxxxxxxxx> wrote in message
news:hot2pi$5ff$1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> On 3/30/2010 7:23 AM, Robert Green wrote:
> > Some of you might remember my question about building a silencing
cabinet
> > for a central vac.  Well, it worked, but too well.  The problem is now
that
> > if something gets stuck in the hose, we can no longer hear the immediate
> > increase in the motor load the way we used to.  On occasion, the unit's
> > motor even shuts down from the overload.
> >
> > Does anyone have any ideas how to detect the "laboring" of the motor so
I
> > can sound a chime or some other alarm when something clogs the pope - I
mean
> > pipe - the Pope has enough problems of his own.  (-:
> >
> > I am going to try a test today with my Kill-0-Watt meter to see if
there's a
> > substantial increase in current draw.  I might be able to use a current
> > sensor to detect the upswing and sound a chime or some other kind of
> > warning.  I don't want to shorten the life of the motor by letting the
> > thermal overload shut it down after it has overheated.
> >
> > Thanks in advance
> >
> > --
> > Bobby G.
> >
> > Crossposted to alt.home.repair;comp.home.automation, follow up in AHR,
> > please!
> >
> >
> Guess I am missing something.
>
> If you are using it and suddenly there is no or greatly diminished
> vacuum wouldn't that be a sufficient indicator that there is a problem?

Well, you see, the house is infested with bats and though we're trained the
werewolf puppies to use the vacuum cleaner to suck up the dead bats and not
eat them, the bats are just the right size to plug the house.  The little
werewolf pups are still learning, so they can't tell when the damn thing
gets clogged.  Then the forget their training and eat the bats when they
don't go down the tube, get rabies and begin to drool all over the carpet
from hydrophobia so the that agitates Cujo, who comes and fights with the
werewolves and all Hell breaks out.  So you can see why it's a problem.

The serious answer is that with a motorized head, there's sufficient
sweeping action to appear as if the vacuum is sucking things in.  Couple
that to the "silencer" cabinet I built around it, it actually IS hard to
tell when vacuum is lost and the motor is making a high pitched noise -
which could indicate that I already have the relief valve that I am thinking
of buying and should test to see if the outlet air is still flowing when the
hose is clogged.  That would indicate that the unit itself has opened an
internal bypass valve.  Good work, George.  You may be on to something . . .

Anyone still reading:  Why DOES the motor RPM increase quite noticeably when
the hose is clogged.  Does an internal vacuum relief valve sense the
blockage and open a relief valve?  Since it would be close to the vacuum
motor, probably in the head, it would not have to draw air from the entire
piping system and thus the motor RPM would soar because of the lightened
load.  Sound right?

--
Bobby G.