Normal Starting Procedure of Perkins 4000 Series Generator Set
Ensure any engine control switch is set to the run position, with the load disengaged. Manually set the air shut off valve (if fitted) to the run position (see Fig. 18), Turn the key switch to the start position, which will energize the solenoid allowing the engine to crank over for a few seconds then start.
Check the instrument panel is showing normal running oil pressure, and the ammeter for charge to the engine batteries.
Allow the engine to run for five minutes checking the instruments are reading correctly. Stop the engine and check the oil and coolant levels, replenish if necessary.
1. Position - closed
2. Position - Open
WARNING!! The cooling system is pressurized - do not remove the filler cap from the radiator whilst the engine is hot. Hand protection must be worn.
The engine is normally stopped by operating an electric stop control via a key switch. In this case it is only necessary to turn the key in an anti-clockwise direction which de-energizes the stop solenoid to stop the engine. The solenoid remain de-energized until the engine is started up again.
With the manual system the stop control must be held in the stop position until the engine stops. Manual stopping can be used to override the electrical system if necessary.
Should the engine stop due to the air shut-off valves being operated, it is imperative that the cause of the fault be investigated immediately.
It is essential to allow the engine to run at no load for 3-5 minutes before stopping to allow the circulating lubricating oil to take the heat away from the bearings and shafts, etc. This is especially important with turbocharged engines where extremely high temperatures are experienced within the turbocharger. Heat rise by suddenly stopping an engine on load can cause seizure of bearings and damage to oil seals.
WARNING!! Do not run the engine excessively at low speeds or loads. If the engine is not being used, shut it down.
NOTE: Excessive idling of the engine will result in only partial burning of the fuel, causing high carbon build-up on injector nozzles, valves, piston rings, etc. Also unburnt fuel will tend to wash the lubricating oil from cylinder bores and dilute the oil in the sump. This can eventually cause inefficient lubrication of bearings and result in seizure.
If an engine is operated on a load less than 25-30% of its rated output: certain symptoms will be observed which may give cause for concern.
The usual results of this operation are heavier than normal lubricating oil consumption, and oil leaks from the air and exhaust manifolds. This condition is particularly evident on standby generator set applications, where a weekly exercise on no load is common practice.
These phenomena are due to the fact that:
1) Turbocharger oil seals are not fully effective on light load, which results in oil being delivered together with the air into the engine air manifolds.
2) The cylinder temperatures are too low to ensure complete burning of all the fuel delivered. This results in an unsightly drip from the exhaust manifold junction glands.
A further result is that of abnormal carbon build-up on the valves, piston crowns and exhaust ports. Thus the normal service interval of see Maintenance Schedules between top overhauls may be reduced. Fuel dilution of the lubricating oil will also occur. It is therefore recommended that the following precautions are observed!
1) Running on light load should be avoided or reduced to the minimum period. If weekly exercising on no load is carried out, the running period should be kept down to say, 10 minutes, or until the battery charging rate returns to normal.
2) Every year the engine or generator set should be run on full load for four hours, to burn off accumulations of carbon in the engine and exhaust system. This may require the use of a 'dummy load'. The load should be built- up gradually from zero over the four hour run.
On standby gensets, air cleaner elements should be changed annually. Oil and fuel fitter elements should be changed every six months. The fuel injectors should be checked every 2 years.
There is absolutely no danger of failure or breakdown resulting from light load operation, providing the above recommendations are followed, in addition to the normal procedures laid down in this manual.
Note: The following image shows 800KW Perkins 4008TAG2A Diesel Generator Set is installed in the machine room.