Spec Sheet

Enclosed Scroll Air Compressor System
SED, SET – 15-30 HP
Powerex • 150 Producon Drive • Harrison, OH 45030 • USA
P 1.888.769.7979 • F 513.367.3125 • www.powerexinc.com
01/2017
Page 1 of 2
Specicaon
General
The Powerex Scroll Enclosed Air Compressor System is designed
to provide clean, dry air for applicaons where the quality of the
compressed air is crical. The standard unit is rated for a maximum
of 116 PSIG.
Air Compressor System
The package shall include mulple oil-less scroll air compressors
and associated equipment. The only eld connecons required will
be system intake if remote intake opon is chosen, exhaust, and
power connecon at the control panel.
Oilless Scroll Compressor Pump
Each compressor pump shall be belt driven oil-less rotary scroll
single stage, air-cooled with absolutely no oil needed for operaon.
The rotary design shall not require any inlet or exhaust valves within
the compressor pump housing or structure and shall be rated for
100% connuous duty. Direct drive compressors shall not be used.
Tip seals shall be of a composite PTFE material and be rated for
8,000 hours operaon. Compressor pump bearings shall be external
to the air compression chamber and pin crank and moving scroll
bearings shall be serviceable for extended compressor life. Bearing
maintenance shall not be required unl 8,000 run hours. Compressor
pumps with bearings that are not accessible for service have a limited
life span and shall not be accepted. Compressor pumps shall have an
integral radial ow fan for cooling. Each compressor pump shall have
exible connectors on intake and discharge. Each compressor pump
shall have a non-metallic heat insulang liner for the discharge air
pipe where it threads into the compressor housing.
Each compressor pump shall be provided with an electric drive
motor, discharge check valve, an air-cooled aer-cooler, and a high
discharge temperature shut down switch. Auxiliary cooling fans shall
operate from 120 volt power provided by the transformer included in
the system controls.
Approach Temperatures
The system is designed with 3 stages of internal aercooling so to
have a maximum approach temperature of 16°F aer the tank and
20°F immediately aer the compressor above ambient. No addional
external aercooling is required for use with a dryer.
Motor
Each compressor shall be belt driven by a 2 pole, TEFC, NEMA
construcon motor that run at 3500 RPM. Motors are EISA compliant
and premium ecient.
Motor Slide Base
Maintenance feature designed for easy adjustment of belt tension
from the motor side on the basemount assembly.
• Robust single screw linear belt tension adjustment.
• Custom compact design.
System Controls
The controls operate the duplex or triplex air compressor modules
as needed in response to a pressure signal from a pressure transducer
located in the system manifold. An illuminated on/o push buon
controls power to the motor starters. When the buon is in the o
posion, the system is merely in stand-by mode, not powered o.
The pressure transducer sends a signal to the programmable logic
controller (PLC) which is programmed to operate two, three or four
compressor modules as needed to maintain the system pressure
requirements. An HMI touch screen interface displays system status
and alarm condions. Pressure sengs are user adjustable within
factory predetermined seng limits.
The PLC will alternate each compressor module based on demand
as well as med alternaon. If a compressor module is running longer
than ten minutes connuously, the control will alternate to the next
available compressor module to equalize run me and synchronize
maintenance intervals. On inial startup or if air pressure drops
rapidly, simultaneous motor starts are prevented by a programmed
three second stagger. One 120VAC control circuit transformer with
primary and secondary fuses is installed for control circuit voltage.
Motor circuit breakers with lockable disconnects are provided for
each compressor module. Operang hours, high temperature alarms,
motor overload alarms, run indicaon, and hours to scheduled
maintenance for each compressor module are displayed on the
screen. All alarm history is kept in the alarm log. Easily navigated
menus are provided to allow the user to select the display condions
and acknowledge the alarms. Remote alarm contacts are provided as
shown on the system wiring diagram.
Inlet Filters
The system includes an inlet lter with a pleated element and a
canister with silencing tubes for each pump. The lters are located
on each pump inside the sound reducing cabinet protected by a
convenient access panel.
Sound Reducing Enclosure
The system is constructed with an internal frame and steel base
system with individual vibraon isolaon mounted compressor
modules. The sound reducing enclosure has a front access panel to
allow service of the electrical controls. The enclosure has rear cooling
air intake and all exhaust air leaves the enclosure from the top.
Oponal Desiccant Air Dryer
The twin-tower desiccant dryer(s) shall be sized for the peak
calculated system demand to provide a pressure dew point of zero
degrees F. Dryer controls shall include a re-pressurizaon cycle to
prevent shocking of the desiccant bed prior to switching towers.
An integral purge saving control system shall be provided and shall
suspend the purge air loss during periods of low demand. When the
dryer is in purge control mode, the tower switching valves shall not
operate, and only one desiccant tower shall be on-line. Dryers that
connue to operate the switching valves on a xed cycle, while in
purge control mode shall not be acceptable. (Dryers ulizing purge