Tech Notes


1.   Position skid on stable level, hardpacked surface. Unit does not require anchor bolts but adequate drainage should be provided.

NOTE:   Leave 10’ side clearance between units or other obstruction for proper        maintenance access.

2.   Connect the compressor unit to the air system by means of suitable piping and discharge block valve.  If the air system is wet, a drip leg should be put in the discharge air piping and used to keep the wet air from feeding back to the compressor and damaging the control system.  Connect the water piping, insuring “water  in” is piped to the “inlet” connection of the water manifold at correct flow and pressure.

3.    The customer must provide a source of clean/dry instrument air to the unit.  A minimum of 80 PSIG control air is required for proper operation of the unit.  The customer must also make arrangements for removal of condensate and drain water from around the unit.

 4.    Connect the electrical ground strap.

5.    Connect the main power.  The wiring and/or transformer(s) must be properly sized, installed, and protected per local and national electrical codes.  For multi-unit installations, each unit should be equipped with a means of isolating it from the other units for maintenance purposes (pole fuses, fused disconnect, breaker, etc.)  This protects the wiring and allows safe access to the switchgear, should maintenance be required.  The customer’s electrical equipment should be sized to provide the correct voltage at starting amperage/current draw (for approx. 10 seconds) and normal running amperage/current draw.  The electrical service must be adequately sized and protected or the unit cannot be operated.  Some units require auxiliary power (see data sheet).  Access panels are provided on each side of the motor starter for power termination.  (Please do not cut holes in the roof).

6.    Minimum operating pressure on three and four state units is 60 PSIG.  If the customer’s system is going to operate at a lower pressure, the customer must provide some means of maintaining this back pressure on the unit(s).

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 Compression Services start-up representative.

8.    In the interest of getting the unit(s) on line as fast as possible and keeping the start-up expenses to a minimum, the customer should realize the start-up representative may need assistance (millwright, electrician, and instrument technician) in performing pre-start checks including the following:

            a.         Verification that the unit is adequately level.

            b.         Check/reset alignment of main drive motor to compressor.

            c.         Check critical compressor clearances.

            d.         Check fluid levels

            e.         Check motor rotation (main leads may need to be switched).

            f.          Check calibration of controls and shutdowns.

9.    The unit will be started by the AirNow Compression Services service representative after the per-start checks have been completed.  After making certain the unit is operating satisfactorily, the service representative will monitor the unit operation and log readings for two (2) hours.  This is an excellent time to begin training the customer’s operating and maintenance personnel.  Customer personnel training will continue until the customer is satisfied with the unit’s operation and his personnel are trained.  At this point, the customer’s representative that will be responsible for the unit will sign the D-RCS service representative’s time sheet and release him from the job.          

HINTS FOR BETTER OPERATION:  This type of unit operates best in an ambient range of 20* F to 100* F, therefore, placement of the unit in the plant is important.  During the summer months, avoid putting the unit in an area that has temperatures higher than ambient.  Locate the unit in as clean and environment as possible.  This helps avoid premature clogging of the air filters and possible internal damage to the unit.

During winter operation, with ambient below freezing (32* F), the attached guidelines for cold weather operation need to be adhered to.



1.         Maintain water flow through oil cooler not in use (sufficient flow to

            Keep water leaving cooler above 50* F).

2.         Maintain water flow from cooler top vents.

3.         Maintain greater than normal flow from condensate drains.


Continue to maintain water flow through machine.  If unit is to be down for an extended period, or maintaining water flow is a problem, please follow the below procedure to completely drain unit.  (Failure to follow this procedure can result in extensive damage to compressor components). 


**IMPORTANT**   Verify all drain points are not plugged and do drain freely.

1.         Close water supply valve and verify no seepage (off skid valve).

2.         Open drain valves on each stage cooler housing, located under water connection   flanges.

            (On C25’s drain is under compressor case).

3.         Remove drain plugs from oil cooler and caps. (Both Coolers)

4.         Verify all on skid cooling water valves are full open.

5.         Verify all drain points are free flowing.

6.         When all water has drained use air hose of ½” I.D. connected to 100 PSI supply

            With no more that 100 feet length to blow out unit from vent connectors.

7.         Full flow air hose into top port of each oil cooler water drain, and allow full flow for  3 Minutes in each top port.

8.         Repeat step (7) only use bottom ports for air blow.

9.         Repeat step (7) exactly.

10.       Reinstall oil cooler drain plugs.




AirNow Industrial Compression Services
10440 N. Central Expy, Suite 1010
Dallas, TX 75231
Phone: 1-972-861-1200