Gas Turbine Systems Technician – Electrical (GSE) A Test 2 Practice

The UPS is feeding the SCU with a relatively high DC bus to keep the load powered reliably and with manageable current. The SCU is designed to operate from 115 V DC, so the UPS provides a stable 115 V DC output to it. If you used a lower voltage like 12 V or 24 V, the SCU would draw much higher current for the same power, leading to larger conductors and more losses, and it might still struggle to stay within acceptable voltage ranges. A higher voltage like 230 V DC would exceed what the SCU is designed to accept. Therefore, 115 V DC is the correct, appropriate supply level for the SCU.