Causes of Voltage Drop in Diesel Generators

Voltage drops can have an adverse effect on productivity and profit and to make sure that they don’t happen too often, we must understand what causes the drops. 

It is well known that a voltage drop in diesel generators is mainly caused by the speed and frequency of the generator system. However, there are many other reasons that can cause a dip in voltage. 

1.  A main reason is that the load applied to the generator is greater than the capacity. This slows the machine down, drops frequency and voltage and leads to exhaust black stacking. The machine could eventually stall. 
2. The Automatic Voltage Regulator (AVR) voltage gain is set too low to respond to load being applied which will put pressure on the genset affect the life of the machine.
3. Clogged fuel injectors and fuel filters will supply less than required fuel to handle the load - this can cause the machine to slow down which will result in the reduction of hertz and volts.
4. Sometimes the speed control setting is not accurately set, and this may cause the generator to trip. 
5. If Automatic Voltage Regulator (AVR) feedback is from generator bus voltage transformer and voltage dips too far, all excitation could be lost and would typically result in an under voltage and over current trip.
6. A loose cable connection in the output terminal can also lead to voltage drops. 

Mahindra Powerol offers 25 kVA & 125 kVA Gas gensets, apart from diesel generators ranging from 5 kVA to 625 kVA. To know more about genset maintenance visit us at www.mahindrapowerol.com/ or call us at 1-800-419-1999