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Starting the Compressor
The sequence that the RECIP compressor goes through during a start is as follows.
1. A five second minimum start delay timer is started. During this time, the capacity stages are unloaded,
the logs are enabled, and any discrete I/O overrides are cleared. The compressor is now in the
STARTING state.
2. After the five second timer expires, the motor is started, the Cooling Control output is energized, and a
15 second up-to-speed timer is started. The user-programmable anti-recycle timer is also started at this
time.
3. If the motor starter auxiliary contact closes within 15 seconds, the starting sequence will continue.
Otherwise, the compressor will be shutdown. Also, low oil pressure alarms will be inhibited within the 25
seconds, pressure failure will be inhibited within 30 seconds.
4. When the 15 second up-to-speed timer expires, the compressor will be loaded to a point greater than or
equal to the Minimum Capacity setpoint using the Fast Stage Delay Time between stages.
5. Once the compressor has loaded to minimum, the compressor transitions to the RUNNING state.
Normal capacity control can now begin.
The RECIP Compressor can be started manually, automatically, or remotely based on the operating mode chosen.
The compressor will not start in any mode if a failure condition exists.
Manual Start
MANUAL START is accomplished by selecting the MAN key. A manual start is used in Manual
mode.
Automatic Start
In AUTOMATIC START the compressor can be started automatically based on suction pressure or
process temperature. Automatic Starting is enabled on the Miscellaneous Control screen under the
SETPT hot key. Once the Auto Start/Stop feature is enabled, the operator must place the compressor
on-line using the Auto key. If the compressor is not needed at that time, it will immediately go to the
Cut-Out state and will start automatically whenever required. If the control parameter is already
above the Cut-In set-point, the compressor will start immediately. A failure or manual stop will take
the compressor off-line.
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