Universal Pump Service Manual
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Start/Hold
- toggles between Start and Hold
Flow and Ba! ery Check
- sets fl ow without aff ecting elapsed time and displays ba# ery status.
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Bat OK
displays if just off the charger
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Bat
displays if the pump can be run
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Bat Lo
displays if the pump cannot sustain itself
Set-up
- sets a delayed start, pump period, and sample period.
Mode
- steps across delayed start, sample period, and pump period modes once the pump is in setup.
Digit Select
- steps across to le$ to set next time digit (keep pressing to return to original position).
Total Elapsed Time (in minutes)
- press and hold bu# on for display on LCD.
Digit Set
- allows user to enter time to start. Keep pressing until desired number appears (0 to 9).
Pump Run Time (in minutes)
- press and hold bu# on for display on LCD.
All programmed sequences are lost when pump is switched off.
To repeat a timed cycle, press the Set-up bu on and Start/Hold.
LCD
Displays ba# ery status, pump mode, pump run time, total elapsed time, and fl ow fault (Figure 1, #1).
When pump enters fl ow fault, the timer does not reset.
Flow Adjust Potentiometer (pot)
Use a small screwdriver to adjust fl ow. Gently turn the pot clockwise to increase fl ow and counterclockwise to decrease
fl ow. Observe fl ow indication on the built-in rotameter (not a primary standard fl owmeter).
There are two cap screws on the top of the pump. The larger one covers the discharge (exhaust) port. The smaller screw
covers the regulator valve for selecting low fl ow mode (Figure 1, #15 and 16).
Universal XR Sample Pump Electrical System
Battery Pack
The ba# ery pack contains fi ve Nickel Cadmium (NiCad) cells in series that provide power to the pump motor. The
ba# ery pack is intrinsically safe and should be replaced only with a UL-Listed ba# ery pack manufactured specifi cally
for Universal XR sample pumps.
Do not charge in hazardous locations. Use only an SKC-approved charger designated for this model to
ensure reliable performance. Failure to do so voids any warranty.
Use of a repaired or rebuilt battery pack voids any warranty and the UL Listing for intrinsic safety .
Failure to follow warnings and cautions voids any warranty.
224-44XRM, PCXR4M, and PCXR8M (MSHA models) contain 4-cell ba ery packs.
Keypad and LCD
Both are powered by the ba# ery pack. If the LCD does not light up when the pump is turned on, there may be a problem
with the ba# ery.
See Troubleshooting.
Motor Control Circuitry
This is a fully electronic system where the voltage applied to the pump motor and the current fl owing through the motor
windings are both sampled and controlled by the analog driving circuit. The circuit is calibrated by adjusting two pots
such that fl ow compensation to within ± 5% accuracy is achieved over the full range of fl ows and back pressures.