Emerson VILTER VSS Installation, Operation And Service Manual page 109

Section 6 • Troubleshooting
Table 6-3. Troubleshooting Guide - General Problems & Solutions (2 of 3)
Problem
Oil Loss Issues
High oil temperature (liquid
injection)
Capacity/Volume Slide
Actuator Alarms/Trips/
Symptoms:
VSS/VSR/VSM/VSH/VSSH Compressor • Installation, Operation and Service Manual • Emerson • 35391S
• Oil return line from coalescing side of oil separator to suction is closed,
not open enough (3/4 turns should be sufficient), or plugged with debris
• The check valve in the oil return line could be stuck closed or the flow
is in the wrong direction
• There may be water in the oil affecting the coalescing elements
• Coalescent elements in need of replacement due to age or damage
(water contamination)
• The operating conditions are not correct (too high of suction and/
or too low discharge pressure) This creates increased gas flow which could
make the oil separator too small
• The suction or discharge check valve is not working correctly causing
oil to escape when the unit stops
• Viscosity of oil incorrect; send sample for testing
• There is an oil leak somewhere in the system
• Check for correct setting of all manual values.
• Check for correct operation of 3-way oil mixing valve.
• If you are controlling a step type oil cooler or a VFD oil cooler, verify
the correct one is selected in the Configuration Screen and the amount of
steps are entered in the Remote Oil Cooler Control Screen.
• Check the oil cooler and associated piping to make sure it is full of oil
before starting.
• Check the oil strainer for debris and clean if necessary.
• Verify that the volume slide actuator is functioning correctly and that
the correct compressor size (type) is selected.
• Check that all fans are working.
• Check for correct fan rotation on the oil cooler.
• Check that your operating conditions are within the "As Sold" design
conditions.
• Calibration method not correct
• Actuator or Gear motor not working, or off on overload
• Slide valve carriage assembly out of position, slides binding
• Cross-shaft gears, broken pins
• Command shaft broken
• Slide valve rack or rack shaft damaged
• Check balance piston movement
• Reference Slide Valve Actuator Troubleshooting Guide
• Check I/O fusing
Solution
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