Re: Central Vac overload

["B Fuhrmann" <b-fuhrmann-usenet@xxxxxxxxxxxxxxxxxxxxxxxxx>]

> External air output pipe ran free when unblocked but dropped to very low
> flow when the hose was blocked.  If there's an internal check valve, it's
> venting to someplace other than the vacuum's output pipe.

No internal check valve on most vacuums.  They expect that the increased
noise will let you know.  With a check valve, almost no change in sound.

> Another theory.  It takes more work to create a vacuum than maintain it,
> so
> when the hose has contracted as much as it can, the motor has less load on
> it and thus the current drops.  With an open vacuum, the motor is
> constantly
> sucking and never achieving even a partial vacuum within the tubing.

A vacuum does it's work by pumping air.  If it is not pumping air, it is not
doing as much work.

The amount of vacuum goes up when it is clogged because air is not flowing
into the system.