ENGINE AR-PRIMARY 2627289 - Caterpillar

Generator Loading
When a generator is installed or reconnected, be sure the total current in one phase does not exceed the nameplate rating. Each phase should carry the same load, allowing the engine to work at its rated capacity. An electrical unbalance can result in an electrical overload and overheating if one phase exceeds the nameplate amperage. When operating with significant single phase loads, the three phase/single phase load combinations must lie below the line on the graph.Block Loading
Block loading is the instantaneous application of an electrical load to a generator set. This load may be anywhere from a moderate percentage of the rated load up to the rated load.The block loading capability of a generator set depends upon engine transient response, voltage regulator response and type, altitude of operation, type of load, and the amount of load at the time the block load is applied.If block load derating is required, refer to (International Standards Organization) ISO 3046 or SAE J1349 Standards. Also reference Engine Data Sheets, Block Loading Transient Response LEKX4066 and Transient Response LEKX4067.Power Factor
Power factor may be thought of as the efficiency of the load - the ratio of apparent power to total power. Power factor is expressed as a decimal and denotes that portion of current supplied to a system doing useful work. The portion of current not doing useful work is absorbed in maintaining the magnetic field in motors. This current, although it is called the reactive load, does not require engine power to maintain it.In most applications electric motors and transformers determine the power factor of the system. Induction motors usually have a 0.8 or smaller power factor. Incandescent lighting is a resistive load of about 1.0 power factor, or unity.The power factor of a system may be determined by a power factor meter or by calculations. Determine the power requirement in kW by multiplying the power factor by the KVA supplied to the system. As the power factor goes up, the total current supplied to a constant power demand will go down. A 100 kW load at a 0.8 power factor will draw more current than a 100 kW load at 0.9 power factor. High power factor will result in full engine load at less than generator rated amperage. A lower power factor increases the possibility of overloading the generator. Caterpillar Generators are designed for a 0.8 power factor unless otherwise specified.Low Idle Adjustment
Electric sets normally have a higher low idle setting than do industrial engines. Low idle will be approximately 2/3 the full load speed of 60 Hz units (4/5 full load speed of 50 Hz units).On electric sets with some Woodward governors, there is no low idle stop. On electric sets with mechanical governors and natural gas electric sets, the low idle is set at the factory, and should only be adjusted by your Caterpillar dealer if adjustment is required. Operating the electric set at low idle speed for an extended time will cause some voltage regulators to shut off.