DeVillbiss Air Power Company MG7-OFTWIN warranty Troubleshooting Guide, Problem Cause Correction

TROUBLESHOOTING GUIDE

PERFORMING REPAIRS MAY EXPOSE VOLTAGE SOURCES, MOVING PARTS OR COMPRESSED AIR SOURCES. PER- SONAL INJURY MAY OCCUR. PRIOR TO ATTEMPTING ANY REPAIRS, DISCONNECT POWER SOURCE FROM THE COMPRESSOR AND BLEED OFF TANK AIR PRESSURE.

PROBLEM	CAUSE	CORRECTION
Excessive tank pressure - safety	Pressure switch does not shut off	Move the pressure switch lever to the “OFF” posi-
valve pops off.	motor when compressor reaches	tion. If the outfit doesn’t shut off, unplug. If the
	“cut-out” pressure.	electrical contacts are welded together, replace the
		pressure switch.
	Pressure switch “cut-out” too high.	Contact an authorized service center to check and
		replace pressure switch.
Air leaks at fittings.	Tube fittings are not tight enough.	Tighten fittings where air can be heard escaping.
		Check fittings with soapy water solution. DO NOT
		OVER-TIGHTEN.
Air leaks at or inside check valve.	Defective or dirty check valve.	A defective check valve results in a constant air leak
		at the pressure release valve when there is pressure
		in the tank and the compressor is shut off. Drain tank
		then remove and clean or replace check valve. DO
		NOT OVER-TIGHTEN.
Air leaks at pressure switch	Defective pressure switch release valve.	Remove and replace the release valve.
release valve.
	Defective check valve.	A defective check valve results in a constant air leak
		at the pressure release valve when there is pressure
		in the tank and the compressor is shut off. Drain tank
		then remove and clean or replace check valve. DO
		NOT OVER-TIGHTEN.
Air leaks in air tank or at air tank	Defective air tank.
welds.
		DO NOT DRILL INTO, WELD OR OTHERWISE
		MODIFY AIR TANK OR IT WILL WEAKEN. THE
		TANK CAN RUPTURE OR EXPLODE. TANK
		MUST BE REPLACED.
Air leaks between head and valve	Leaking o-ring.	Torque head screws to 8 ft. lbs. If this does not stop
plate.		leak, replace o-ring.
Pressure reading on the regulated	It is normal for “some” pressure drop to	If there is an excessive amount of pressure drop
pressure gauge drops when an	occur.	when the accessory is used, adjust the regulator
accessory is used.		following the instructions on page 6.
		NOTE:
		Adjust the regulated pressure under flow
		conditions (while accessory is being used).
Air leak from safety valve.	Possible defect in safety valve.	Operate safety valve manually by pulling on ring. If
		valve still leaks, it should be replaced.
Knocking Noise.	Defective check valve.	Remove and clean, or replace.
Compressor is not supplying	Prolonged excessive use of air.	Decrease amount of air usage.
enough air to operate accesso-	Compressor is not large enough for air	Check the accessory air requirement. If it is higher
ries.	requirement.	than the SCFM or pressure supplied by your air
		compressor, you need a larger compressor.
	Restricted air intake filter.	Clean or replace air intake filter. Do not operate the
		air compressor with the filter removed. See page 8.
	Hole in hose.	Check and replace if required.
	Check valve restricted.	Remove and clean, or replace.
	Air leaks.	Tighten fittings. (See Air Leaks Section of Trou-
		bleshooting Guide.)

12 — ENG