[Illustration: FIG. 238.]
[Illustration: FIG. 239.]
In many places the pressure on the mains is insufficient to raise the
water to the upper floors or through improperly designed systems of
piping the pressure may be so diminished as to make the flow extremely
weak or the difficulty in securing proper water supply may be due to
inconvenient location with reference to water mains. _The automatic
electric house tank pumping plant_ has been designed and perfected to
meet these conditions; the electric plant is connected to some power or
lighting circuit and provided with an automatic attachment requiring
no more care than can be given by any casual attendant. Such an
installation avoids the smoke, ashes, dust and objectionable odors that
accompany steam or gas plants.
The accompanying diagram shows the general arrangement of the automatic
electric house system used with a tank in the upper part of the
building and the pump in the basement or cellar. The operation is as
follows:
When water is being delivered to the tank, the float rises until the
upper knob makes forcible contact with the switch lever, opening the
switch and stopping the pump. When water is withdrawn from the tank,
the float falls until the lower knob makes contact with the switch
lever, which again closes the switch and starts the pump. The supply
of water is thus maintained within the tank without the aid of an
attendant. The accompanying illustration, Fig. 238, shows a Worthington
house tank pump of 500 gallons per hour capacity belted to a General
Electric direct current motor, the pump and motor being mounted on the
same base.