Gardner Denver AUTO SENTRY-ES+, Operating And Service Manual

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13-9-653 Page 4
PROTECTIVE SHUTDOWNS
The controller will shut down the unit following any fault detected in the following devices. Long-term problems will
have a brief blowdown period before fully shutting down. Following a shutdown, a message will be displayed, with
the top line indicating
"SHUTDOWN" and the lower line indicating the cause. The shutdown light will be steadily lit if
the cause still exists, or will flash if the cause has been cleared. Refer to the troubleshooting section for detailed
information about each shutdown. To resume operation, the cause of the shutdown must be corrected and the
controller reset by pressing the [STOP/RESET] key.
Motor protective devices - Overload heaters are furnished for the starter in the voltage range specified. There are
three (3) overloads in the starter of proper size for the starter and its enclosure. Note that motor nameplate current
must be multiplied by 0.577 for wye-delta starters. The display will indicate that an overload relay has tripped. The
overload relay is reset by pressing the button on the relay itself, then the controller may be reset. Motor current
(amps) and voltage must be measured in the affected motor wiring to locate the cause for high current. Overload
relays provided in standard units are sensitive to both overload and phase imbalance for improved motor protection.
Proper starter coil and contact action is also monitored and errors in operation will cause a shutdown with the cause
displayed as a starter or starter contact error.
High temperature - The compressor is protected from high discharge temperature by a thermistor probe located in
the compressor discharge elbow. This controller will shut the compressor down if temperature exceeds 225
°
F (or as
set in setup adjustments) or if rapid temperature rise is detected. Reservoir / separator temperature is also
monitored, and will provide high temp shutdowns. The location of the temperature fault will be displayed. Thermistor
probes are also checked for open or shorted circuits, and the display will indicate the location of the defective probe.
CAUTION
Machine damage will occur if compressor is repeatedly restarted after high temperature stops
operation. Find and correct the malfunction before resuming operation.
Separator differential pressure - The pressure drop across the separator is continually monitored by the controller.
The unit will be shut down at a differential pressure of approximately 15 psid.
The pressure drop can be monitored at any time by pressing the separator key on the diagram twice. This should be
checked while the compressor is delivering at full capacity. A service advisory comes on to recommend maintenance
prior to this shutdown.
High pressure - The controller will first attempt to unload and blow down the unit if excessive pressures are detected
in the reservoir or the plant system. If unsuccessful, a shutdown will occur. Shutdown will also occur if a defective
transducer is detected, or improper zero adjustments are detected. The display will indicate the location of the high
sensed pressure or transducer (xducer) error. Check that all adjustments have been properly made, and all
connections are secure.
Low sump pressure - The controller will shut down the unit if inadequate oil reservoir pressure is detected after
loading the compressor. If this occurs, check the wiring and piping to the solenoid valves.
Emergency stop - Press the emergency stop button to shut down the unit and the controller. To restart, pull the
button out to its normal position and reset the controller. This should be used for emergency purposes only - use the
keypad [STOP/RESET] for normal controlled stopping.
Power failure - Following power interruptions, the controller will remain in a shutdown state (unless programmed for
auto restart).
External device - This input is provided for user- or dealer- installed devices needed by specific applications. Other
shutdown field selectable messages include: high vibration, phase relay, low voltage relay, water press, and motor
overtemp.
Amp sensor failure - The optional current sensor used with the controller is used for operational tuning and advisory
purposes only. The only shutdown functions are those when the controller senses improper operation. These may
be disabled if no sensor is installed.