Condition Possible faults Suggested remedy 3. Insufficient air receiver pres- a. Air leak(s) a. Check and correct as necessary sure b. Air intake filter clogged b. Clean or replace c. Air consumption exceeds unit capability c. Decrease demand or add unit d. Pressure gauge defective d. Replace gauge e. Unloader jammed e. Disassemble and clean 4. Insufficient pressure at point a. Leaks or restrictions a. Check hose and piping of use b. Air filter clogged b. Clean or replace c. Service hose too small c. Replace with larger hose d. Excessive air requirement d. Decrease consumption or add unit 5. Fuses blow Wrong fuse size Replace with correct size 6. Fuses of proper size blow, a. Motor overload a. Check motor reset kicks out b. High ambient temperature b. Provide ventilation c. Wiring wrong size c. Have electrician check wire size d. Unit starting against a load d. Check unloader mechanisms Repair or replace 7. Compressor does not speed up a. Voltage drop at motor terminals due to a. Consult power supplier Change to larger cross-section ineffective mains or undersized supply cable, if necessary cable b. Ambient temperature too low b. Install compressor in frost proof room If no other location available.  heat room c. Pressure relief valve of air pressure switch c. Check operating mechanism of valve If out of order, replace air malfunctioning pressure switch as a unit d. Unloader plunger jammed d. See 2a e. Solenoid valve out of order e. Replace solenoid 8. Pressure in receiver rises a. Air pressure switch incorrectly set or out of a. Set switch to stop compressor at rated maximum pressure Re- above maximum and causes order place switch if It does not respond safety valve to blow b. Solenoid valve defective b. Remove and test valve on outside mains supply line Replace, if out of order c. Unloader piston jammed c. Inspect unloader assembly Replace parts as necessary 9. Receiver does not hold pres- Non-return valve leaks Check for broken valve plate and springs ure 10. Too frequent starting and too a. Air pressure switch incorrectly set a. Increase pressure short operating periods b. Non-return valve leaks b. See 9 c. High condensate level in receiver c. Drain condensate more frequently 7