Metacentre CX Box
Page 3
2. INTRODUCTION
The CX Box is intended as an advanced
compressor interface unit with inherent
functionality for monitoring and regulation of a
compressor that is equipped with a compatible
variable output regulation system.
PD
DP
PS
The CX Box provides optional ‘local pressure
sensor’ connections. The compressor delivery
pressure (PD), local system pressure (PS) and
air treatment differential pressure (DP) can be
monitored and displayed. The detected local
pressure (delivery or system) is available on
the system network and can be utilised by a
management system unit for advanced
pressure related functions. A local air
treatment differential pressure alarm can also
be implemented.
PI
PD
The CX provides ‘Internal’ reclaimer vessel, or
sump, pressure detection. The differential
pressure between the internal pressure (PI)
and delivery pressure (PD) can be monitored
and displayed. An internal air/oil filtration
differential pressure alarm, and excessive
internal pressure alarm, can be implemented.
The CX Box is equipped with several digital
(remote volt-free contact) and analogue
temperature/pressure inputs. Each can be set
to monitor and display status or value with the
option to respond with an Alarm(Warning) or
Trip(Shutdown) condition. With the addition of
the optional CX Expansion Box, additional
digital and analogue inputs can be made
available.
The CX Box is equipped with a ‘compressor
control mode’. This mode enables total control
and monitoring (including Star/Delta motor,
Fan and Load solenoid control) of a
compressor unit that is not equipped with it’s
own control system.
2.1 Management System Connectivity
CX Box
The CX Box connects to a Management
System using an industrial two wire RS485
data network (Multi485).
2.2 Interface Mode: Regulation Types
The CX Box provides advanced monitoring
and control functionality for the following
compressor types:
Load/Unload (L mode)
For a compressor equipped with single
pressure switch, or remote load/unload digital
input, regulation.
3-Step (3S mode)
For a 3-step reciprocating type compressor
fitted with two pressure switches.
5-Step (5S mode)
For a 5-step reciprocating type compressor
fitted with four pressure switches.
Poppet Valve (V mode)
Rotary Screw; where each valve can be
energised from a volt-free relay contact.
The CX Box can accommodate 2 valve, 3
valve and 4 valve regulation systems.
Modulation Valve (AR mode)
Rotary Screw or Vane; where the modulation
valve can be controlled with the use of a 4-
20mA proportional pressure regulation valve.
Spiral Valve (AR mode)
Rotary Screw; where a pressure activated
spiral valve can be controlled with the use of a
4-20mA proportional pressure regulation
valve.
Variable Speed Inverter Drive (AR mode)
Inverter Drive; where the inverter drive can be
regulated from a 4-20mA signal.
