Load Inventory

A load inventory should identify each item, its electrical characteristics and its operational role. Include the supply arrangement, starting method and whether the load is expected to run during generator operation. This makes the schedule useful for continuity planning as well as capacity assessment.

Distinguish connected load from simultaneous demand

Installed equipment does not necessarily operate at full rating at the same time. Record the basis for diversity or measured demand rather than applying an unexplained reduction. Conversely, loads that restart together after an interruption may create an event not visible in the normal operating average.

Capture each load

equipment name
quantity
kW
kVA if known
voltage
phase
PF
efficiency where relevant
motor starting method
starting current if known
duty

Diversity

But do not apply an arbitrary diversity factor without understanding the process.

Output

Generator sizing gets easier when uncertainty is made visible instead of hidden inside one load number.

Keep demand assumptions visible

Connected load, expected maximum demand and the proposed starting sequence describe different aspects of the requirement. Identify estimates and any diversity or coincidence assumptions, then replace them with measured or equipment-specific information as the design develops.

Maintain the inventory as the facility changes

Record the date, source and owner of the load information. Add planned equipment separately from installed equipment, and revise the schedule when operating patterns change. A traceable inventory allows later reviewers to understand the conditions behind the original generator assessment.

Start Engineering Review

Start Engineering Review. Share the application, location and information available so the next discussion can address your actual requirement.

Related guidance

Engineering intent

Load Inventory should be evaluated as part of the complete power system rather than as an isolated catalogue item. Operating duty, connected load, interfaces, protection, controls, installation conditions, testing requirements and lifecycle consequences determine whether the arrangement is appropriate.

Engineering considerations

That is why the load must be understood dynamically. Utility normally supplies the facility; generator supports designated loads during failure. Generator serves as a principal source under the applicable manufacturer rating. Generation is required for a project, shutdown, outage or temporary facility. Generator must interface with UPS, BESS, solar, existing generators, switchgear or other infrastructure. The correct generator cannot be selected until the required emergency operating state is understood. Do not begin by adding every electrical nameplate. Can This Load Start While the Generator Is Already Carrying Other Loads? This second question can materially change the sizing result. without ever operating all 2,000 kW simultaneously. Do not apply an arbitrary diversity factor without understanding the process.

Selection and design considerations

Where load changes materially with time, assessment should consider an appropriate observation period. A generator sized only for peak load may spend much of its life far below that condition. Peak load should represent the highest credible sustained demand. The transient may last only seconds but still influence source selection. What is the largest increase in demand the generator may experience at one time? The largest step can matter more than the total running load. After an outage, not every load necessarily needs to return immediately. Diversity recognises that not all installed loads operate simultaneously. Avoid applying one generic diversity factor across every project. Demand factor can help compare actual maximum demand against connected load.

Integration and protection considerations

The nameplate alone does not describe the complete operating requirement. Connected Load Is Not the Same as Operating Load A site may have 800 kW of connected equipment while its actual operating demand varies between 250 kW and 650 kW. Another facility with the same connected load may periodically start: The second site can impose a substantially different requirement on the generator. Equipment expected to operate at the same time. Loads that can be disconnected if available generating capacity falls. A motor may draw substantially more electrical current while accelerating than during normal operation. The starting method can materially change the electrical demand placed on the generator. A prime-power system should therefore be assessed against its worst credible operating transition, not just the steady-state load.

Testing, commissioning and verification

But it is a descriptive relationship—not a universal constant. A different facility, process or operating season may have a different demand pattern. This often produces a more accurate power requirement than a generic diversity percentage. But emergency or maintenance philosophy may alter the assumption. Do not simply remove intermittent loads from the assessment. Different starting methods can produce different source demands. That structure is worth retaining as an input philosophy, even though the old workbook formulas themselves require independent validation before becoming production calculators.

Operating and lifecycle considerations

Operational intelligence is about relationships—not isolated numbers. A generator configuration approved at mobilisation is based on a defined demand. Rental systems can start correctly and gradually become overloaded because additional equipment is connected over time. Operations planning should provide a method of identifying and approving material load changes. Loads previously assumed to be non-simultaneous may begin operating together as the project changes. Operational monitoring should therefore validate the design assumptions over time. Where practical, controlled sequencing may reduce unnecessary simultaneous demand. Operations should preserve that sequence where it forms part of the approved power architecture.

Direct answer

The practical decision for Load Inventory should be based on verified load, equipment, interface and site information. Where equipment-specific data, regulatory applicability or a project study is required, this guidance does not replace that verification.

Related Reddy Generators pathways

Load-estimation control

Load estimation is not a simple sum of connected nameplates. Reliable source and distribution sizing requires the operating demand, diversity, starting duty, harmonics, criticality, future growth and emergency operating scenario to be defined before generator, transformer, UPS, cable and switchgear ratings are finalised.