AIRNOW TRAILER MOUNTED AIR
COMPRESSORS INSTALLATION GUIDELINES
1. Park trailer with rear wheels level. Lower both trailer
support legs using appropriate load
bearing support under each leg if not on concrete. If site
is reasonably level, trailer can be disconnected from the
tractor at this point. Before disconnecting tractor, block
the trailer wheels front and back.
NOTE: Leave 10’ side clearance between units or other
obstructions for proper maintenance access.
2. Level the trailer length-ways using the support legs.
Recheck transverse level as in step 1. (Good leveling of the
trailer facilitates motor/compressor alignment later.)
3. Connect the compressor unit (4” – 125# flange) to the air
system by means of a suitable hose, piping, and discharge
block valve. If sir system is wet, a drip leg should be put
in the discharge piping and used to keep the wet air from
feeding back to the compressor and damaging the control
4. Connect the main 460 volt power. This wiring should be
installed per national and local codes. Extra care should be
taken where the wires go through the trailer floor to insure
the wires are protected from rubbing a hole in the
insulation. The wiring and transformer must be properly
sized and protected from breakers. For multi-unit
installations, each unit should be equipped with a breaker.
This protects that unit’s wiring and allows safe access to
the switchgear should any maintenance be required. Customer
electrical equipment should be sized to provide 460 volts to
2000 starting amps and 550 running amps. The unit is
protected with an under-voltage device that will prevent the
unit from operating if the voltage dips below 410 volts.
5. Connect the electrical ground strap.
6. Minimum operating pressure on the unit is 60 psig. If the
system is going to operate at a lower pressure, customer
must provide some means of maintaining this back pressure.
Also, in this case, the customer must pipe instrument air to
the unit, since 80 psig minimum control air is required for
the proper operation of the unit.
7. In order to minimize the Customer’s start-up time and
expense, steps 1 through 6 should be completed prior to
arrival of the AirNow service representative. Also, in the
interest of getting the unit on line as fast as possible and
keeping start-up expense to a minimum., please note that the
AirNow service representative may need assistance
(millwright, electrician and instrument man) in performing
pre-start checks including the following:
a. Verify trailer is level.
b. Check/reset alignment of main drive motor to compressor.
c. Check motor rotation. (Main leads may need to be
8. The unit will be started by the AirNow service
representative after the pre-start checks have been
completed. After making certain the unit is operating
properly, the service representative will monitor the unit’s
operation and log readings for 2 hours. This is an ideal
time to begin training of operating and maintenance
personnel. Training will continue until the customer is
satisfied with the unit’s operation and his personnel are
HINTS FOR BETTER OPERATION: This air cooled unit operates
best in an ambient range of 20 degrees F to 100 degrees F;
therefore, placement of the unit in the plant is important.
During the summer, avoid putting the unit in an area that
has temperatures higher than ambient. Locate the unit in as
clean an environment as possible. This will prevent external
fouling of the coolers and also help avoid premature
clogging of the air filters and possible damage to the unit.