Communis 500 KVA DG Set Operation Procedure

How to operate & dg a. b, & check Communis 500 kva dg set.

@goutamdasg6 not sure about the operation model of this particulate DG or genset. But find below general procedure for the start and stop of Diesel Generators.


The following procedures are adopted for starting diesel generator set using battery.

  1. Push button (Manual)
  2. Auto start (Auto)
  3. Test mode (For testing purpose)
  4. The mode of operation can be selected by means of selector switch.

Push Button Start/ Manual mode

After pressing the start push button and turning the ignition key toward start
position, the battery is connected to the starter which cranks the engine shaft resulting in
the start of the engine. This arrangement can also be provided in small DG sets. This
requires least physical efforts to start DG set. To prevent damage to the starter, do not
push the start button for more than 10 to 12 seconds.

Auto Starting System/ Auto mode

This method is adopted where the supply from the generator is regularly required.
In this mode, the DG set starts automatically in case of (i) mains failure, (ii) low/high
mains voltage beyond 150-250 V for single phase DG set and 360-460 V for 3 phase

DG set (iii) single phasing or phase reversal of main supply. When the engine starts,
and alternator reaches the preset voltage, the DG contactor closes and automatically restores the supply to the load.

The auto start system makes three attempts to start, in case it fails to start, the starting system automatically disconnected and locked out. After restoration of healthy
mains voltage, the DG contactor opens and main supply extended to the load. However
the DG set continuous to run for 3 minutes and shutdown after that if mains supply
remain stable.

During the above mentioned 3 minutes, if the mains fail again, the DG shutdown
sequence discarded and the DG contactor closes again to restore the DG supply to the

Test mode

In this mode all functions are likely to manual mode but DG supply can not be
transferred to load. This mode is provided for the purpose of testing the DG set.


Before starting the engine, perform daily maintenance checks. Follow the
instructions given below for reliable operation:
• To prevent damage to the starter, do not push the start button for more than 10
to 12 seconds. Wait for at least 2 minutes between each attempt to start.
• If the engine does not start after three attempts, check the fuel supply system and
fuel level in fuel tank. Absence of blur or white exhaust smoke during cranking
indicates that no fuel is being delivered.
• Move the ignition key from start position to idle as soon as the engine starts.
• Monitor the oil pressure and coolant temperature gauges frequently.


• Remove the load from the engine.
• Run the engine few minutes (3 to 5 minutes) before routine shut down on no load.
It will allow the lubricating oil and coolant to carry heat away from the
combustion chamber, bearings, shafts etc.
• Shut off the engine if oil pressure or coolant temperature is exceeding the
specified limits.
• Avoid continuous operation of the engine with low or high coolant temperature, it
may damage the engine.


Most failures give an early warning. Look and listen for changes in performance,
sound or engine appearance that can indicate service or engine repair is needed. Some
changes to look for are as follows:

• Engine misfires
• Vibration
• Unusual engine noise
• Fuel, oil or coolant leakage
• Sudden change in engine operating temperature or oil pressure
• Excessive smoke
• Loss of power
• An increase in lube oil consumption
• An increase in fuel consumption