Always remove compressor head pressure by depressing the red
unloader valve tab on the pressure switch while setting the circuit
breaker to ON. Failure to depress the red tab will result in the tripping of
the circuit breaker.
d. Restart Procedures. To restart the compressor, set the circuit breaker to
e. Load Factors.
(1) Normal load. The recommended maximum operating load under normal
circumstances is 3.8 cubic feet per minute (cfm). Refer to Figure 1-5 for the load factors
of various dental instruments. The normal recommended load is equivalent to the
continuous operation of one high-speed handpiece and one venturi type oral evacuator
at maximum capacity.
(2) Expedient load. The compressor has the capability of providing
sufficient air to drive two operating units as a short-time expedient measure. The
maximum operating load recommended in such a situation is continuous operation of
two saliva ejectors at maximum capacity and intermittent operation of two high-speed
Figure 1-5. Load factors.
If operation in an expedient situation is necessary, you may have to adjust the
control block in the dental operating and treatment unit to permit higher
pressure to the handpieces. You do this in order to ensure their peak
efficiency when the two systems are operating simultaneously. After use in
an expedient situation, check the dryness indicator. If it is not blue, refer to
Lesson 2, paragraph 2-2e(2).
f. Turn-off Procedures. To turn off the compressor at the end of each day,
use the following procedures:
Set the circuit breaker to OFF.
(2) Drain the storage tank by placing the tank drain hose outside the transit
case and opening the drain valve.
(3) When the pressure gauge indicates zero psi, close the drain valve and
place the drain hose inside the transit case.