Frick QUANTUM Maintenance Manual page 12

S90-010 M
Page 12
SYMPTOM
MOTOR LOAD CONTROL(FORCED UNLOAD)
OCCURS AT HIGH MOTOR AMPS
MOTOR LOAD CONTROL(FORCED UNLOAD)
OCCURS AT LOW MOTOR AMPS
PRESSURES ON THE OPERATING DISPLAY
DO NOT APPEAR CORRECT
COMPRESSOR with Slide Valve DOES NOT
AUTOMATICALLY LOAD OR UNLOAD*
COMPRESSOR that steps on Capacity DOES
NOT AUTOMATICALLY LOAD OR UNLOAD*
* If applicable
FRICK QUANTUM CONTROL PANEL
MAINTENANCE
PROBABLE CAUSES and CORRECTIONS
The current transformer is used to convert the AC motor amps to a DC
voltage signal for the microprocessor. If the %FLA reading from the
Operating display is incorrect, contact the Frick Service Department.
The current transformer is used to convert the AC motor amps to a DC
voltage signal for the microprocessor. If the %FLA reading from the
Operating display is incorrect, contact the Frick Service Department.
TEST 1 - Shut down the compressor and allow pressures to equalize.
Discharge pressure and oil pressure should have the same reading.
TEST 2 - If either oil pressure or discharge pressure read different
pressures, one or both transducers are at fault. Valve off the suction
transducer from the unit and open the vent valve on transducer mani-
fold to atmosphere. If the suction transducer reads atmospheric pres-
sure, then the transducer in Test 1, which agrees with the suction
transducer, is correct. The transducer which disagrees is defective.
NOTE: Reference the Pressure Transducer Conversion Data Chart.
Verify that the Slide Valve Mode [AUTO] key has been pressed and
AUTO appears under Slide Valve Mode on the "Operating Status"
display.
If the problem persists, see the Troubleshooting section SLIDE VALVE
DOES NOT LOAD and/or UNLOAD.
Verify that the Capacity Mode [AUTO] key has been pressed and
AUTO appears under Capacity Mode on the "Operating Status" dis-
play.
If the problem persists, see the Troubleshooting section COMPRES-
SOR DOES NOT LOAD and/or UNLOAD.