RWB II PLUS MICROPROCESSOR CONTROL
MAINTENANCE
S70-200 OM
Page 22
TROUBLESHOOTING FRICK SBC MICROPROCESSOR SYSTEM (Continued)
SYMPTOM PROBABLE CAUSES and CORRECTIONS
LIQUID INJECTION SOLENOID Verify that the Liquid Injection TXV is modulating properly and not feeding
DOES NOT ENERGIZE (LIQUID excessive liquid to the compressor. When oil temperature drops too low, the
INJECTION REFRIGERANT CUTOUT microprocessor SHOULD de-energize this solenoid.
- LICO)
Output 6 controls the Liquid Injection Solenoid. If 120VAC is found across
Wires 13 and 2, the Liquid Injection Solenoid should be energized. If not,
the solenoid is defective. If 120VAC is not found when the LED for Output 6
is on, check the fuse (FU6).
HI VI LIQUID INJECTION PORT Output 7 controls the Hi Vi Liquid Injection Port solenoid. If 120VAC is
(OPTIONAL) SOLENOID DOES NOT found across Wires 12 and 2, the Hi Vi Liquid Injection Port Solenoid
ENERGIZE should be energized. If not, the solenoid is defective. If 120VAC is not
found when the LED for output 7 is on, check the fuse (FU7).
NOTE: This output should only be on when the Vi is above 3.4
ECONOMIZER (OPTIONAL) Output 8 controls the Economizer Solenoid Valve. If 120VAC is found across
SOLENOID DOES NOT ENERGIZE Wires 11 and 2, the Economizer Solenoid should be energized. If not, the
solenoid is defective. If 120VAC is not found when the LED for Output 8
is on, check the fuse (FU8).
NOTE: The economizer output should only be on when the slide valve is at or
above the 90% position.
ALARM HORN DOES NOT ENERGIZE Output 9 controls the Alarm Horn. The Alarm should turn on only when there
is a prealarm. If the Alarm does not sound when these conditions are
found, check for 120VAC across Wires 10 and 2. If 120VAC is not found,
check the fuse (FU9).
CONTROL PANEL DOES NOT Inputs 2 through 4 can be used to operate the compressor from a remote
RESPOND TO REMOTE CONTROL location. NOTE: Check the Operating display to verify that the compressor
SIGNALS and the slide valve are in the REMOTE MODE.
If 120VAC is found (across Wires 21 and 2, 22 and 2, and 23 and 2) and the
input does not turn on, consult Frick Company.
MOTOR LOAD CONTROL The current transducer is used to convert the AC motor amps to a DC voltage
(FORCED UNLOAD) OCCURS signal for the microprocessor. If the %FLA reading from the Operating
AT LOW MOTOR AMPS display is incorrect, consult Frick Company.
PRESSURES ON THE OPERATING TEST 1 - Shut down the compressor and allow pressures to equalize. Suction
DISPLAY DO NOT APPEAR pressure, discharge pressure, and oil pressure should have the same reading.
CORRECT
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 manifold to
atmosphere. If the suction transducer reads atmospheric pressure, then the
high pressure transducer which agreed with the suction transducer in Test 1
is correct. The transducer which disagreed is defective.
NOTE: A 1% tolerance is allowed for all transducers.
COMPRESSOR DOES NOT AUTO- Verify that the [AUTO] key has been pressed and AUTO appears under SV Pos
MATICALLY LOAD OR UNLOAD on the Operating display.
If the problem persists, see the Troubleshooting section SLIDE VALVE
DOES NOT LOAD and/or UNLOAD.
DISPLAY SCREENS DISPLAY A loose or improper connection between the displays and the SBC is
SCRAMBLED PATTERN OR indicated. Remove fuse (2FU, 10 amp) for 15 seconds and, then, restore to
LISTS ALPHABET reset the displays.
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