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Detonation Sensing
The
MPI Detonation Sensing Interface System utilizes a pair of highly sensitive
accelerometers to detect detonation. In the event of detonation the
DSI signals the MPI Control System, via 4/20 ma control signal, which
responds by immediately retarding the timing thus eliminating the potentially
harmful effects of continuous detonation.
Features:
- Utilizes advanced piezoelectric accelerometer sensors to provide real-time analog signal
- Signal is proportional in amplitude to the levels of vibration detected
- Sensors respond over wide range of frequencies up to 10 KHz
- Retards timing to reduce vibration intensity or eliminate it entirely
- Sensor range – 0 – 500 g’s
- Detect any source of vibration
Benefits:
- Easy to use Controller interface
- Detects detonation tendencies at low levels before they reach greater intensity and cause engine damage
- Flexible controls, useful information for operators
- Wide bandwidth allows detection of most mechanical vibration sources including detonation
- Complete installation kits, wiring guidelines and sensor kits provided
Specifications:
Power Requirements: 18-30 VDC 300mA max.
Controller
Operating Temp range: -20C to 70C
Sensor Operating Temp Range: -40C to
120C
Sensor Frequency Range: 20-5000 Hz
Sensor Sensitivity: 10mV/g 500g
F.S.
Control Inputs:
The 1/REV signal must be provided. Two interfaces
are available for customer convenience.
Option 1. MPI_ISO_1/REV-MPI_ISO_RTN: This
input connects back to the MPI Isolated_ 1/REV output pair.
Option
2. 1/REV_In: This interface is designed to be used directly
by a mag pick sensor. It can be wired in parallel to the MPI 1/REV
mag pick
up. It can also be connected in parallel to a Hall-Effect sensor
if in use.
Control Output: Vanalog_Out: This is a 1-5 volt open-circuit
output level that when terminated externally by 250 ohm resistor
becomes
a 4-20 ma current signal. Note:The MPI Ignition system already has
an internal 250 ohm resistor across this input.
Shutdown Output: This
is an Open-Drain type interface. Maximum current when activated:
1.0 amps. Maximum externally applied voltage when de-activated: 100V.
Panel Controls and Indicators:
1. Power On Switch. Applies 24 VDC to the
electronics and sensors. The knock sensor cable should never be removed
or installed
with power on. Power On Indicator provides verification that power
is applied.
2. Sensor 1(2) Low Level lights: These indicators will
come on when the engine is running over 400 rpm and the sensor
output is below minimum level. Its an indication that the sensor is
not
sensing vibration levels during normal running operations. This may
be due
to the sensor becoming loose or the cable is removed or the engine
is running at idle or unloaded when very low levels of vibration
are generated.
3. SHUTDOWN: This indicator will come on if the system
detects
three heavy detonation present for three successive revolutions.
The Shutdown output will activate and it can be tied into a panel
or directly
to the MPI to kill ignition.
4. SHUTDOWN RESET: After a shutdown
occurs this push-button clears the shutdown indicator and de-activates
the
shutdown output for subsequent start-up.
5. Internal indicators
1. Flashing amber led indicates firmware is operating normally
Applications
as of 2nd QTR 2004
1. Any Caterpillar 3500 series engines.
Applications
Currently under test
1. Waukesha 5790G Engine.
Literature:
For more information about this product, you can download the related literature here:
