Welch Vacuum 2534 WOB-L Pinston Pump - Manual (Page 6)

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2.50 INTAKE AND DISCHARGE PROVISIONS
2.51 The Two regulators and two gauges make it easy to meet your vacuum and pressure
requirements. The vacuum regulator and vacuum dial gauge is attached to the intake port. The
vacuum regulator allows the vacuum level to be set between roughly atmospheric pressure
and the maximum vacuum allowed for the pump model. A moisture trap keeps water from
accidentally being drawn into the unit. The pressure regulator and pressure dial gauges are
attached to the discharge port. The pressure regulator allows discharge pressure to be set
between atmospheric and the maximum possible for the pump model. Discharge air is fi ltered
and noise is muffl ed with a fi lter.
PROPERLY IDENTIFY THE INTAKE AND DISCHARGE OF THE PUMP
Intake Discharge
Pressure/Vacuum Pump
Be sure to call Welch technical service prior to start-up at (847) 676-8800 if you have any
questions.
2.60 ELECTRICAL POWER
2.61 Power Source Review
Review the power source and the motor rating to be sure they agree in voltage, phase, and
frequency. Serious damage may occur to the motor if it is connected to an improper voltage. All
Welch pumps must be grounded. Grounding reduces the risk of electric shock in the event of an
electrical short circuit. The plug must be plugged into a properly grounded outlet.
Consult your local electrical codes if you have doubts.
2.62 Overload Protection
Motor thermal overload protection is made available by the motor manufacturer as an aid to
minimize motor failure. Overload protection is a standard feature on both 50 and 60 Hz single-
phase-motors. The motors have automatic overload protection. Automatic reset protection is
designed to reset itself after a predetermined cooling period. If the fault to the drive remains
unaltered, the motor will cycle on and off until the fault is corrected.
2.70 VACUUM CONNECTIONS
2.71 All pressure/vacuum pumps come with intake and discharge hose barbs which accept 1/4” ID
rubber pressure/vacuum hose. Hose clamps should be used to hold the hose in place. Since all
three models operate in the viscous fl ow regime, the small diameter of the hose will generate
minimal conductance loss. For best results, Welch recommends the length of the tubing between
the pump and the chamber be kept as small as possible.