Gardner Denver 40 HP, Operating And Service Manual

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13-8-638 Page 18
CONTROL DEVICES
Controller - This compressor unit features the "AUTOSENTRY
®
" controller, which integrates all the
control functions under microprocessor control. Its functions include safety and shutdown, compressor
regulation, operator control, and advisory/maintenance indicators. The keypad and display provide the
operator with a logical and easily operated control of the compressor and indication of its condition. The
controller is factory adjusted for the compressor package, but allows tuning for specific applications.
Detailed instructions for the controller are found in the “AutoSentry” Controller Operating and Service
Manual.
Figure 4-2 – KEY PAD
Relief Valve -
A pressure relief valve is installed in the final discharge line and set to approximately 120-
125% of the unit's full load operating pressure for protection against overpressure. Periodic checks
should be made to ensure its operation.
The relief valve should be tested for proper operation at least once every year. To test the relief valve,
raise the system operating pressure to 75% of the relief valve set pressure and manually open the valve
by turning the cap.
WARNING
When the relief valve opens, a stream of high velocity air is released, resulting
in a high noise level and possible discharge of accumulated dirt or other debris.
Always wear eye and ear protection and stand clear of the discharge port when
testing the relief valve to prevent injury.
CAUTION
Never paint, lubricate or alter a relief valve. Do not plug vent or restrict
discharge.
WARNING
Operation of the unit with improper relief valve setting can result in severe
personal injury or machine damage. Ensure properly set valves are installed
and maintained.