The Functioning of The GPU
Written by Start Pac
The majority of starter generators and motors work on turbine engines that operate with 30 volts without the occurrence of any damage. At the moment that the starter is activated, the greatest amount of amperage draw is felt. This figure could reach up to 1000 amps depending on the gas turbine start up engines.
During the startup process, as the motion is sustained, amperage requirements significantly fall down through the activation cycle. The battery used for this effect would thus need to be effectively in order to cope with the load pressed on it as the voltage is dropped during start up. Generally speaking, when the load is applied to the battery, the voltage would decrease. To ensure that turbines are properly started, the drop in the voltage level would need to be kept low.
Lowered levels of battery voltage would let out lower amounts of amperage. Some starter motors might even bring down batteries to about 15 volts while the startup is being activated. However, most engines companies would recommend a voltage of 28.5 during startup to be able to effectively cope with the drop in voltage.
It is for this purpose that external ground power units (GPU) are often used. A GPU is useful to the turbine engine at startup as it sends 20% of the required energy to the motor and this facilitates the process while at the same time generating less heat. Another benefit of a GPU is that its use leads to an increase in turbine life.
Start Pac specializes in starting and ground power units. Some of their products offerings also include portable power supply and lithium batteries.