GOUNDING INSTRUCTIONS
This product should be connected to a grounded, metallic, permanent, wiring system; or an
equipment-grounding terminal or lead on the unit.
AIR LINE PIPING
Connection to air system should be of the same size or larger than discharge pipe out of
unit. The table gives recommended minimum pipe sizes. A union connection to the unit and
water drop leg is recommended. Install a flexible connector between the discharge of the
unit and the plant air piping. Plant air piping should be periodically inspected for leaks using
a soap and water solution on all pipe joints. Air leaks waste energy and are expensive.
COMPRESSOR
MODEL
VTR20
WTR45
Never use plastic pipe or improperly rated metal pipe. Improper pipe material can burst and
cause injury or property damage.
OPERATION
This compressor has been inspected, thoroughly tested, and approved at the factory. For this
unit to give long satisfactory service it must be installed and operated properly.
This compressor has been designed to run at 100% duty cycle.
Simplex units have a pressure switch that senses changes in receiver pressure and automatically
starts and stops the compressor at the preset pressure limits. If the receiver pressure falls below
the cut-in pressure setting of the pressure switch the compressor will run until the cut-out
pressure setting of the pressure switch has been reached.
Duplex units have lead and lag pressure switches and an automatic alternating system to
distribute the load evenly between the two compressors. The pressure switches sense changes
in receiver pressure and automatically start and stop the compressor at preset pressure levels. If
receiver pressure falls below the cut-in pressure setting of the lead pressure switch but remains
above the cut-in pressure setting of the lag pressure switch, only one compressor will run until
receiver pressure reaches the cut-out pressure of the lead pressure switch. The next time the
pressure in the receiver drops, the system automatically starts the other compressor. If the
receiver pressure falls below the cut-in pressure setting of the lag pressure switch, both
compressors run until receiver pressure reaches the cut-out pressure of the lead pressure switch.
Minimum Pipe Sizes for Compressor Air Lines
(Based on clean smooth Schedule 40 Pipe)
25'
3/4 (3/4)
3/4 (3/4)
3/4 (1-1/4)
1 (1-1/4)
Values in ( ) are for duplex unit.
IF3163 Rev A Page 13
50'
100'
3/4 (3/4)
1 (1-1/4)
200'
300'
3/4 (3/4)
3/4 (3/4)
1 (1-1/2)
1 (1-1/2)