The electrical power requirement for the suction apparatus is 120 volts of
alternating current (vac). The unit has the aforementioned convenience outlet which
you can use as an additional power source for another item of electrical equipment. As
you can see from the schematic, the convenience outlet is hot (energized) as soon as
the power cord is plugged into a grounded wall outlet.
Before plugging the power cord into a wall outlet, ensure the power
switch is off and the speed control (Variac) is turned to the minimum or
a. When S-1 is closed, the pilot light is energized and the 120vac is also applied
to A1-1 and A1-2, energizing the primary side of the Variac (A1). The secondary side of
A-1 is from A1-1 to A1-3 and is the power source for M1, the motor.
b. By rotating the Variac speed-control knob clockwise or counterclockwise, the
operator varies (increases or decreases) the speed of the motor and the amount of
suction produced. To verify the unit is creating negative pressure (or suction), attach
the tubing and collection bottle to the unit. Fill another bottle with water, attach it to the
system, and turn the unit on. Increase the speed (RPM) of the motor and observe the
vacuum gauge. The gauge should indicate 20 to 30 centimeters of water (cmH2O) as
water is being drawn from the water-filled bottle into the collection bottle.
Section II. MAINTENANCE AND REPAIR PROCEDURES
PREVENTIVE MAINTENANCE CHECKS AND SERVICES
Preventive maintenance checks and services (PMCS) is the Army's way of
ensuring every piece of its equipment is ready to perform properly when called upon for
service. A maintenance allocation chart (MAC) is not yet available for this piece of
a. Suggested Maintenance Plan. The manufacturer suggests the following
maintenance procedures be followed.
The equipment operator (EO) inspects and cleans the apparatus on a
(2) The operator also checks apparatus tubing daily for any holes, splits, or
breaks incurred during use.
(3) The EO cleans the collection and overflow bottles daily unless
disposable collection bottles are used.