R-Series Electric
22
CQF3473 v.01
Operation & Service
April 17, 2018
Guide to Maintenance (continued)
COMPRESSOR VALVES: If compressor fails to pump air or seems slow in filling up tank, disconnect unit
from power source and remove valves and clean thoroughly, using compressed air and a soft wire
brush. After cleaning, exceptional care must be taken that all parts are replaced in exactly the same
position. All joints must be tight or the compressor will not function properly. When all valves are
replaced and connections are tight, close ball valve at tank outlet for final test. Valve gaskets should
be replaced each time valves are removed from pump.
CENTRIFUGAL UNLOADER AND UNLOADER PRESSURE RELEASE VALVE: The centrifugal unloader is
operated by two governor weights. It is totally enclosed and lubricated from the crankcase of the
compressor. When compressor starts, the governor weights automatically open, compressing the
main spring, allowing the unloader pressure release valve to close. When the compressor stops, the
main spring returns the governor weights to normal position, opening the unloader pressure release
valve and unloading the compressor. This prevents overloading the motor when starting. If air
continues to escape through the governor or unloader pressure release valve while operating, this is
an indication that the unloader pressure release valve is not closing tightly and may be held open by
a foreign substance which has lodged against the seat. In order to correct this, remove the governor
release valve cap, allowing access to unloader pressure release valve spring and ball. Clean
thoroughly and return parts in the same order in which they were removed. See Centrifugal
Unloader section in parts list for diagram. Loose drive belts can also cause unloader to leak by
preventing the compressor from reaching proper speed. (See “BELTS” page 24).
CHECK VALVE: The check valve closes when the compressor stops operating, preventing air from
flowing out of the tank through the pressure release valve. After the compressor stops operating, if
air continues to escape through the release valve, it is an indication that the check valve is leaking.
This can be corrected by removing check valve and cleaning disc and seat. If check valve is worn
badly, replace it.
Before removing check valve, be sure all air is drained out of tank and power is disconnected.
Failure to do so may result in injury or equipment damage.
THE INTERSTAGE PRESSURE RELIEF VALVE is provided to protect against interstage over pressure and is
factory set for maximum pressure of 75 PSIG. DO NOT RESET. If the pressure relief valve pops, it
indicates trouble. Shut down the unit immediately and determine and correct the malfunction.
Inspect the head valves. Serious damage can result if not corrected and can lead to complete
destruction of the unit. Tampering with the interstage pressure relief valve or plugging the opening
destroys the protection provided and voids all warranty.
COMPRESSOR LUBRICATION: Fill crankcase to proper level as indicated by oil sight gauge. Keep
crankcase filled as required by usage. It is recommended that only Champlub recip lubricant be
used. This is an ISO 100, non-detergent industrial oil with rust and oxidation inhibitors specially
formulated for reciprocating compressors. Do not mix oil types, weights, or brands.
