f. Adjust nut (A) to increase or decrease low operating point as required, to set low operating point at 175 PSI (1210
KPa). This should be done by increments of a half turn at a time.
g. After each half turn, start compressor unit and allow compressor unit to pressurize to high operating point when it
will shut off. Then slowly bleed off air by depressing inflator gage handle. As air escapes and air pressure in air
receiver decreases, note at what pressure the compressor unit begins operation to repressurize air receiver. If
this does not occur at 175 PSI (1210 KPa), repeat step "f" until low operating point of 175 PSI (1210 KPa) is
h. After low operating point is attained, again turn compressor unit off and begin to adjust high operati ng point, nut
(B), in half turn increments. High operating point should be 195 PSI (1350 KPa) maximum.
j. After high operating point has been attained, replace pressure switch cover and secure it in place with pressure
switch cover nut.
FIGURE 4-5. PRESSURE SWITCH ADJUSTMENT
4-9. COMPRESSOR PUMP REPLACEMENT.
Disconnect compressor unit from main power supply before servicing replacing or
repairing parts of equipment, to avoid personal injury.