Maximum GPU Voltage is which value?

Maximum GPU Voltage is which value?

• A. 25 V
• B. 28 V
• C. 29 V
• D. 30 V

Answer: (D)

In aircraft electrical systems, the Ground Power Unit (GPU) supplies the airplane’s 28 V DC system. The key idea is that there is a nominal voltage the system expects, but there is also a defined upper limit to protect equipment from overvoltage and to cover transient spikes. The loads and protective circuitry are designed with tolerance that brings the maximum safe voltage up to 30 V. So the external power can be 28 V nominal, but it must not exceed 30 V to avoid damaging avionics and other systems. This is why 30 V is the maximum value allowed for GPU voltage. Lower options like 25 V would undervolt the system, and 28 V is the nominal, not the maximum; 29 V is a transient level but not the official upper limit.

In aircraft electrical systems, the Ground Power Unit (GPU) supplies the airplane’s 28 V DC system. The key idea is that there is a nominal voltage the system expects, but there is also a defined upper limit to protect equipment from overvoltage and to cover transient spikes. The loads and protective circuitry are designed with tolerance that brings the maximum safe voltage up to 30 V. So the external power can be 28 V nominal, but it must not exceed 30 V to avoid damaging avionics and other systems. This is why 30 V is the maximum value allowed for GPU voltage. Lower options like 25 V would undervolt the system, and 28 V is the nominal, not the maximum; 29 V is a transient level but not the official upper limit.