September 2015 Service and Repair ManualManifoldsPart No. 1268498 Z-30/20N • Z-30/20N RJ • Z-34/22 • Z-34/22N 537-4 Valve Coils7-4Valve CoilsHow to Test a CoilA properly functioning coil provides anelectromotive force which operates the solenoidvalve. Critical to normal operation is continuitywithin the coil that provides this force field.Electrocution/burn hazard.Contact with electrically chargedcircuits could result in death orserious injury. Remove all rings,watches and other jewelry.1 Tag and disconnect the wiring from the coil tobe tested.2 Test the coil resistance.Coils with 2 terminals: Connect the leadsfrom the ohmmeter to the valve coil terminals.Coils with 1 terminal: Connect the positivelead from the ohmmeter to the valve coilterminal, then connect the negative lead fromthe ohmmeter to the internal ring of the valvecoil.Result: The resistance should be withinspecification, plus or minus 30%.Result: If the resistance is not withinspecification, plus or minus 30%, replace thecoil.Valve Coil ResistanceSpecificationNote: The following coil resistance specificationsare at an ambient temperature of 68°F / 20°C. Asvalve coil resistance is sensitive to changes in airtemperature, the coil resistance will typicallyincrease or decrease by 4% for each 18°F / 10°Cthat your air temperature increases or decreasesfrom 68°F / 20°C.Valve Coil Resistance SpecificationDescription SpecificationSolenoid valve, 3 position 4 way, 20V DC(schematic items A, J, K, U, V, Y, AA,BB and CC)22 ΩProportional solenoid valve, 24V DC(schematic item H)19.5 ΩSolenoid valve, N.C. poppet, 20V DC(schematic item M)23.5 ΩSolenoid valve, N.O. poppet, 20V DC(schematic item P)23.5 Ω
