On site testing of Katolight engine generator sets for industrial, agricultural and commercial applications:

All Katolight engine generator sets shall be started and run weekly with all available system loads for a minimum of 30 minutes. Generator sets shall be exercised at a level that exceeds 30% of the nameplate rating.

If the system load available during the weekly test is not equal to at least 30% of the nameplate rating, the unit should be run at a minimum of 80% of rated load with use of an external artificial load bank for 2 to 4 hours once annually to prevent possible engine damage. Operating Katolight generator sets with low loads can cause increased lubricating oil consumption. It can also cause a loss of power on gaseous-fueled sets. Low load operation of diesel powered sets can also result in oil/fuel leaking into and from the exhaust manifold (wet stacking), which will lead to cylinder wash and shortened engine life.

Should you require assistance in annual load bank testing, contact your authorized Katolight Service Center for their services and load bank rental. Katolight will not accept any liability for units that are showing signs of being run for extended time without adequate load.

 Recommended Procedure for Load Bank Testing

 There have been many questions asked regarding the methods used to calculate load levels for Load Bank Testing.  The most common confusions are determining what amp rating to test by.  Here are the basics.

The nameplate information is the place to start.  First determine the generator rating (kW not KVA).  The kW is the kilowatt capacity of the unit.  Once you have this number, multiply by 1,000, this will then be the watt output of the generator.  When testing with a resistive load bank the load will be the unity power (1.0pf).  To calculate the max amperage of the unit, you need to use the following formula:

Three phase amps = Watts (kW x 1000) ¸ Line to Line Voltage ¸1.732 (Square Root of 3)

Single phase amps = Watts ¸ Line to Line Voltage

Another method to use is the following:

The nameplate amps x nameplate power factor = resistive load amp rating. 

Here are some examples: A unit model D500FRX4 the kW is 500, the voltage is 277/480, 3 phase, and the power factor is .8, as stamped on the nameplate.  The formula to use is 500 X 1000 = 500,000 ¸ 480 ¸ 1.732 = 601.43.  The amount of this load can be tested to with a resistive load bank is 601 amps.  Here is a single-phase example: The nameplate tells us it is a 500kW, 120/240 single phase 1.0 power factor.  The formula would look like this: 500,000 ¸ 240 = 2083 amps, this is the max load with a resistive load bank. 

This may be old news for some, but with new people working in the field, it is important to know and use this information.