Product Manual
400C OPERATING INSTRUCTIONS
IMPORTANT: The 400C has a maximum working pressure of 150 PSI and is capable of 33% duty cycle.
Always operate the compressor at or below the MAXIMUM PRESSURE RATING of the compressor.
Operation exceeding maximum pressure ratings and or duty cycle will result in damage to air compressor.
1. Your air compressor is equipped with an AUTOMATIC THERMAL OVERLOAD PROTECTOR.
This feature will protect the air compressor from overheating and causing permanent damage to your air
compressor. The thermal overload protector will automatically cut o power to your air compressor should
the internal operating temperature of the air compressor rise above safe levels during excessive use.
2. Should your air compressor automatically shut o during use, turn power to the system o. The automatic
thermal overload protector will automatically reset when internal temperature of the air compressor drops
below safe levels. After allowing air compressor to cool o for about 30 minutes, you can safely resume use
of the air compressor by turning on the system.
3. To prevent discharge of your battery and to provide peak performance, it is recommended that you keep
the engine running while the air compressor is in use.
4. ONLY OPERATE THE AIR COMPRESSOR IN WELL-VENTILATED AREAS.
400C Compressor Maintenance & Repairs:
1. Periodically check all electrical and tting connections. Clean and tighten as needed.
2. Periodically check all mounting screws. Tighten as needed.
3. Replace air lter element periodically. Replacement frequency depends on operating frequency and
operating environment. For frequent use in dusty environment, you should replace air lter element
more often.
4. Regularly clean dust and dirt from compressor.
5. Your air compressor is equipped with permanently lubricated, maintenance-free motor.
Never lubricate compressor.
6. Repairs should be performed by Manufacturer or Manufacturer’s Authorized Service Agencies only.
CAUTION: Never touch the air compressor or ttings connected to the air compressor with bare hands during
or immediately after use. Leader hose and ttings will become very HOT during and after use.
400C Compressor Installation Tips:
1. Always use the remote intake lter option when possible. This will extend the service life of your compressor.
2. If noise reduction from vibration is desired, using the remote mount option for the inlet lter can reduce
operation noise by up to 25%.
3. Always mount the compressor at a point higher than the inlet port of the tank.
This will keep moisture from being able to seep back to the tank.
4. When mounting the compressor, use a paint pen on the rubber isolators and cover the side to go against the
chassis or mounting location. Then, simply stamp the compressor against the chassis to make an imprint of
exactly where to drill the mounting holes for the compressor.
PRESSURE SWITCH WITH RELAY INSTALLATION (USE CONTENTS OF PARTS PACKAGE #3)
Your VIAIR Heavy Duty Onboard Air System comes complete with a pressure switch with relay that will turn on
the compressor at 110 PSI, and o at 145 PSI. The pressure switch has a 1/8" NPT inlet at the bottom that will
need to have the supplied 1/8" female to 1/4" male reducer tting installed (using thread sealant) to allow it to
be plumbed directly to your air tank.
Pressure Switch with Relay Installation Tips:
1. Never install your pressure switch in direct line from the inlet port coming from the compressor.
Tank pressure can be misread by the pressure switch. Mount the pressure switch on the tank where it
receives reading from deected air.
2. Never use a pressure switch that is rated beyond your compressor’s rated maximum working pressure
(150 PSI).
3. Replace with Pressure Switch with Relay P/N 90111 if the pressure switch fails.
USER MANUAL
HEAVY DUTY ONBOARD AIR SYSTEM