How To Complete Correct Sizing Calculation For Gas Generator Set Project

Author : HitokaCece HitokaCece | Published On : 23 Sep 2026

Improper sizing represents one of the costliest mistakes for gas generator‑set investment. Oversizing increases initial procurement expense and leads to long‑time low‑load running which damages unit life. Undersizing causes unit overload when key equipment starts and cannot satisfy actual power demand. Sizing work is not equal to simple summation of all equipment name‑plate power. Multiple site‑related factors need full consideration.

Gas Generator Set Load Classification Sorting

First step of sizing is sorting project load into different categories. Distinguish critical necessary load and non‑critical optional load. Critical load maintains basic safety and core production function during power failure. Non‑critical load can be cut off when generator set supplies power. Record rated power of every critical load. Do not add all loads together blindly. Clarify which devices must keep running under generator‑set backup mode. This forms basic data foundation for power‑capacity calculation.

Gas Generator Set Motor Starting Current Consideration

Plenty industrial loads contain motor‑driven equipment such as pump, fan and crusher. Motor generates large starting impulse current at startup moment. This transient power demand is higher than steady‑state rated power. If sizing calculation only adopts steady‑state power value, gas generator set will face voltage drop or protective trip while motor starts. Different starting modes bring different impulse magnitude. Direct‑on‑line starting creates the biggest impact. Take motor starting characteristic fully into account during power‑capacity evaluation.

Gas Generator Set Site Environmental Influence Factor

Altitude, ambient temperature and humidity will exert impact on actual output capacity of gas generator set. Higher altitude reduces air density, which lowers effective power output of internal‑combustion engine. High‑temperature environment also brings power derating. Many buyers only reference standard‑condition rated power from specification sheet without checking site derating coefficient. Unit nominal power cannot be fully exerted under plateau or high‑temperature workshop. Derating value must be reserved in sizing calculation for special geographical location.

Gas Generator Set Operation Mode Confirmation

Confirm whether gas generator set works as standby backup power or prime continuous power source. Standby unit only runs during grid‑power outage. Prime‑power unit undertakes long‑time continuous power‑supply task. These two working modes follow different power‑rating standard. Standby power rating cannot be treated as prime power index. If standby‑rated unit runs for long‑term continuous output, service life will suffer serious loss. Clear definition of operation mode avoids wrong power‑grade selection.

Gas Generator Set Reasonable Redundancy Setting

Appropriate redundancy reserves cope with future load growth and transient‑load impact. Excessive redundancy should be avoided to prevent chronic low‑load operation. General project keeps reasonable redundancy ratio after finishing real‑load calculation. For projects with extremely high power‑supply reliability requirement, multi‑unit parallel scheme can be adopted instead of one single large‑capacity unit. Keya New Energy completes sizing analysis combining load list and site condition data. Scientific calculation balances equipment investment and long‑term running reliability.