During my service engineer job, I visited many engineering firms all over India. Very rarely I had found the right procedure to Start-Stop the Air Compressor.
The common picture I saw everywhere was when I asked an operator to start the compressor, he just goes to the main switch and pressed the ON button.
The operator never looks, whether the compressor is in unloading mode or not, the service valve is open or not, cooling water is flowing or not, nothing.
Likewise, when I asked to stop the compressor, he just put the main switch OFF. No due care is taken to start-stop the reciprocating air compressor.
This is not the proper procedure for start-stop the compressor.
You can achieve the best performance from your compressor when it is operated by the right procedure.
This is the machine that may run for several weeks without stopping. Many Engineering units run their compressor for a week without stopping.
This much performance can be achieved when you have the right information about the start-stop of a compressor. All utility engineers and operators will have to read this article carefully.
Here I will share the most important information with you, follow it and you will avoid many problems due to wrong start-stop.
Important Points for Start-Stop of Compressor
How to Start Reciprocating Air Compressor
01) Keep Air Compressor in unload condition by use of unloaders. If you are using electro-pneumatic controls, put the control supply ON of the unloader unit.
02) Turn on cooling water to remove the airlock from the water cooling system. Check the inlet water pressure and flow.
03) Ensure the belt wheel is free to rotate by rotating it by hand, for several rotations. This tip is particularly useful when you are starting the compressor after a very long period.
04) If force-feed lubricator is fitted, check the oil level and operate it for 8-10 turns so the oil will reach the cylinders for initial lubrication. Check oil level in the crankcase and top up if required.
05) Check the position of safety shut down switches. It should be in normal working condition.
06) Drain Condensate from Intercooler & Aftercooler by opening the valve manually.
07) Check V-belt tightness.
08) Check the position of the stop valve, and open it, to flow compressed air to a receiver.
09) Start the Air compressor by pressing the ON button from a control panel.
10) Check the oil pressure with a pressure gauge. If not shown, stop the unit immediately.
Some more Procedures to Start-Stop the Air Compressor
11) Check oil flow from each lubricator pump. Three to four drops/revolution is sufficient.
12) Put Compressor at load condition after 3 to 5 minutes of normal operation.
13) Regulate water flow to a cylinder, intercooler, and aftercooler if required.
14) Check Inter stage Pressure. It should be within range.
15) Check for leaks in air, water, and oil pipelines. If found any leak, rectify it immediately.
16) Check the voltage available to each terminal and the current drawn by the motor. It must be as per requirement.
17) Check Discharge air temperature. The maximum discharge air temperature allowed is 170-degree centigrade.
18) Drain condensed water from air receiver, pulsation bottles, and moisture separators. Keep the valves slightly open.
19) Check for loose nuts and bolts; tighten if required at regular intervals of running operation.
20) Check for unusual noises. Don’t avoid any abnormal sounds it may lead to a major breakdown.
How to Stop Reciprocating Air Compressor
01) Unload the Air compressor by using an M-type unloader. If you are using electro-pneumatic controls, put a toggle switch at the unloading position. Allow the compressor to run for 5 minutes in unload condition.
02) Press the OFF push button to stop the electric motor.
03) Shut off the cooling water by closing the water inlet valve.
04) Drain condensed water from collection points.
05) Discontinue Power supply to a starter.
If you follow the above precautions of start-stop, your Air Compressor will give you the best performance for long period. By following the above start-stop tips you can increase the efficiency of the compressor also.
Besides this information, you are suggested to read something more from below engineering books