QS5 Operating Manual 9.0 Trouble-Shooting Problem Possible Cause Does not achieve good vacuum 1. Loose/open fittings Remedy 1. Make sure all connections are tight, gas 2. Not enough oil ballast & oil fill cap are 3. Dirty/contaminated oil closed and unused inlet is not open. 4. Old/dirty/non-vacuum 2. Add oil to level indicated rated hoses 3. Change oil 5. Gas ballast open in deep vacuum operation 4. Use new hoses rated for 6. Pump has reached the deep vacuum end of its useful life 5. Close gas ballast 6. Service or replace pump Oil discolored 1. Excess moisture in oil, 1. Change oil or oil burnt Oil leakage 1. Loose fittings/connections 1. Ensure oil drain and related fittings are tight 2. Over-filled with oil 2. Check oil level, drain extra if necessary 1. Power disconnected 1. Connect power 2. Thermal protection has shut pump down 2. Allow pump to cool, will re-start on its own Failure to start 3. Cold start condition 3. Subject pump to heat to raise the ambient 4. Operating voltage too temperature low 4. Check operating voltage 5. Power supply cord too long 5. Use shorter power supply cord 6. Foreign matter has entered pump 6. Check and clean pump 7. Blown fuse 8 7. Check fuse (near power receptacle) and replace if necessary.