Fault Conditions; Lights And Gauges; Operational Check Points - Gardner Denver RHC Series Instruction Manual

3.3 Fault Conditions

A. Faults; Compressor Protection
1. Manual Reset
a. OIL PRESSURE: Low oil pressure - Oil protection
switch "OPS" ensures sufficient oil pressure to
prevent burnout of compressor. Switch opens
after time delay on low oil pressure differential.
After ten (10) minutes or fault correction, manu-
ally reset the unit (by selecting fault message and
pressing F1) on the operator interface.
CAUTION: SWITCH MUST NOT BE RESET MORE THAN
THREE (3) TIMES WITHIN A THIRTY (30) MINUTE
PERIOD. If the problem persists, contact
manufacturer's service department.
NOTE: Dryer will pumpdown and display "STAND-
BY" after reset.
b. HIGH REFRIG PRESS: High (high or head) side
refrigerant pressure - The PLC opens the compres-
sor control circuit if the high side pressure ex-
ceeds set point. For settings, refer to Technical
Data Sheet. Manually reset the unit (by selecting
fault message and pressing F1) on the operator
interface.
CAUTION: DO NOT RESET UNTIL HEAD PRESSURE IS
250 PSIG, 17.6 KGF/CM
NOTE: Dryer will pumpdown and display "STAND-
BY" after reset.
c. MTR STARTER: Motor starter protector - Motor
starter thermal overload protectors "SP" open on
excessive motor current. Reset is manual at motor
starter.
2. Automatic Reset
a. LOW REFRIG PRESS: Low (low or suction) side
refrigerant pressure - The PLC opens the compres-
sor control circuit if the low side refrigerant
pressure drops below set point. For settings refer
to Technical Data Sheet. Reset is automatic.
b. SSMP: Solid state motor protection - Solid state
motor protection "SSMP" provides three (3) leg
protection with three separate sensors. Reset is
automatic after two minute delay.
WARNING: Use OHM meter only (6 volt max.) to
check (SSMP) module. Measure resistance only
between each sensor terminal and common
terminal. Make no attempt to apply external
voltage or current to sensor terminals or damage
will result requiring compressor replacement.
B. Faults, Informational
1. HI EVAP AIR TEMP: High evaporator air temperature
indicates when process gas temperatures exceeds
"HTS" set point.
2. LOW WATER PRESS: Optional - Indicates that water
supply pressure is below set point.
3. CHECK SEPARATOR: Optional - Indicates pressure drop
across dryer exceeds set point.
10
2 OR LESS.
4. INLET AIR TEMP: Optional - Indicates inlet air tempera-
ture is greater than 120°F, 49°C.
5. LOW EVAP AIR TEMP: Optional - Indicates air tempera-
ture in evaporator is below the set point.
6. DRAIN LEVEL HIGH: Optional - Indicates condensate
level in automatic drain(s) is above the set point.
3.4 Light and Gauges
A. Power-on indicator (white) illuminates when unit is
energized.
B. General alarm (fault) indicator (red) illuminates if a fault
condition occurs.
C. Air inlet pressure gauge indicates pressure of com-
pressed air at inlet nozzle of air-to-air precooler/
reheater. This is a local mount gauge on the inlet pipe.

3.5 Operational Check Points

1. Check to see that power-on light is illuminated.
2. After sufficient running time with load on unit (ap-
proximately 15 minutes) check to see that General
Alarm light is out and there are no fault messages
displayed.
3. Check air inlet pressure gauge to ensure correct
pressure is being supplied to dryer. Lower than design
pressure may result in dryer being overloaded.
4. Check for proper oil level on compressor crankcase
sight glass. Oil level should be visible.
5. Check refrigerant sight glass. Presence of bubbles
after five (5) minutes of operation may indicate that
more refrigerant is required.
CAUTION: Leak test refrigeration system for refriger-
ant leak and repair any leaks before adding refrigerant.
Do not add refrigerant unless other symptoms sug-
gest low refrigerant charge.
6. Check liquid moisture indicator which is incorporated
in the liquid refrigerant sight glass. The moisture
indicator should show a "Dry" system.
NOTE: On initial start-up if indicator shows "Caution"
or "Wet" proceed with start-up and recheck after
twenty-four (24) hours. If indicator shows "Wet,"
refrigerant filter/ dryer core may need to be replaced.
7. Check refrigerant suction pressure display for proper
reading. See Technical Data Section.
8. Check head pressure display for proper reading. See
Technical Data Section. Refer to Section 4.2.B for
possible causes of high pressure readings if present.
9. Water-cooled units - Check to ensure that water flow
to condenser is sufficient and at the proper tempera-
ture and pressure. See Technical Data Section. Insuffi-
cient flow may indicate that strainer is plugged
10. Check condensate drains. Check that manual shut off
valves ahead of drains are open. After sufficient
running time check for visible signs that drains are
discharging.