ANGI ENERGY SYSTEMS CNG Operation And Maintenance Manual page 11

will continue to run in this mode until the discharge
pressure reaches the STOP pressure set point
defined in the controller (or the compressor faults)
4) COOL-DOWN
Once the controller determines that the storage
pressure is above the STOP pressure set-point,
the load/recirculation
compressor motor and fan motor continue to run
for a period of time to allow the compressor to
unload and cool. After a cool down timer expires,
the fan and compressor motors are stopped and
the control system returns to STAND-BY mode.
5) FAULTED
During any of the modes mentioned above, the
control system may detect a shutdown condition
and the machine will be placed in FAULTED mode.
In this mode the suction valve is closed and the
fan and compressor motor is stopped. The nature
of the fault is announced on the front panel of the
control enclosure.
2.4.1.2 Fault Conditions
A number of digital inputs and analog transducers
are monitored by the control system to initiate a
machine shutdown due to faulted operation.
Only a subset of all the inputs and transducers are
monitored for fault conditions in any one of the
possible modes of operation. For example, the
compressor oil pressure reading is ignored during
STAND-BY operation.
The fault tables below identify possible fault
conditions.
DIGITAL FAULTS
DESCRIPTION
Keyswitch
Reset
Oil Level Low
High Vibration
Low Oil Flow – Compressor
High Final Pressure
Emergency Stop Activated
High Liquid Level – Receiver
High Lube Temp – Compressor
Too Many Starts Per Hour
Note: An Emergency Stop Fault is an indication
that either a remote or local E-Stop pushbutton
has been depressed (or a rate of rise heat
detector has detected a fire or the gas detector
has detected a gas leak).
ANGI OPERATION AND SERVICE MANUAL
valve opens and the
HIGH ANALOG FAULTS
DESCRIPTION
High Suction Pressure
High Receiver Pressure
High Final Pressure
st
High 1 Stage Pressure
nd
High 2 Stage Pressure
rd
High 3 Stage Pressure
th
High 4 Stage Pressure
High Oil Pressure – Compressor
st
High 1 Stage Temperature
nd
High 2 Stage Temperature
rd
High 3 Stage Temperature
th
High 4 Stage Temperature
LOW ANALOG FAULTS
DESCRIPTION
Low Suction Pressure
Low Receiver Pressure
Low Final Pressure
st
Low 1 Stage Pressure
nd
Low 2 Stage Pressure
rd
Low 3 Stage Pressure
th
Low 4 Stage Pressure
Low Oil Pressure – Compressor
st
Low 1 Stage Temperature
nd
Low 2 Stage Temperature
rd
Low 3 Stage Temperature
th
Low 4 Stage Temperature
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Rev 2006/06