MatrixMonitor™ IOM - Rev 4 - 4/11/2013
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or more fans go into surge. The second yellow LED (right) is turned on if the MatrixMonitor™ determines
that there is a problem in reading any of the transducers. If a transducer has gone bad or a signal has
reached the maximum making it impossible to calculate the actual flow or pressure this LED will be lit. It
will also light when the grease monitor trips or the fan vibration limits are exceeded.
The keys along with text prompts from the graphic display are used to configure the control to the
application through menu driven setup screens and display real time fan array performance information
screens.
Piezometric Pressure Port
The piezometric pressure port is a pressure tap that is usually inserted into
the throat of the fan inlet cone at its smallest diameter. The tap connection
fitting is on the high pressure side of the cone. The tap is piped from the
downstream side of the cone through the back plate of the fan so that
connection can be made to the pressure transducer located on the inlet
side of the fan air seal wall. If the design flow through the fan is higher than
the rating of the pressure transducer on the fan sensor board (FSB) an
alternate low pressure tap placed higher on the cone will be used. Only one
port will be connected to the pressure transducer on the FSB. The taps are
mounted on the inlet cone with the port end exposed to the flow side of
the inlet cone. They are press fit into the cone and the connection
side is on the
high pressure
side of the inlet cone. The fan sensors are mounted
on the inlet side of the fan back plate so the
pressure tubing that connects to the pressure tap is
routed to the inlet side of the back plate through a
bulkhead connector. The connection is made to the
low pressure side (negative side) of the pressure
transducer on the FSB. The high pressure side of
the pressure transducer is left open to sense the
fan inlet pressure. The section titled “Throat and
Cone Tap Flow Range” below gives the basic
information about when the throat tap or the cone tap should be
used.
Fan Sensor
The fan sensor is a custom assembly that contains the special MEMS pressure transducer, a temperature
transducer, a tri-axial accelerometer, and a high performance 32 bit RISC microcontroller to read and
process the transducer data and communicate with the host. The fan sensor board (FSB) has the
pressure transducer mounted on the top side and the components and connection points on the bottom
side. It is designed to mount on a standard 2 x 4 outdoor utility electrical box. The pressure transducer
Connection to Throat Tap
Location of Pressure Taps
