100kVA genset planning: build the load schedule and starting sequence

Start with what you know about the load

You can start a genset rental or purchase enquiry with the job, location and dates before completing the technical worksheet. State whether 100kVA is a project requirement or only a starting point for discussion. Choose Not sure yet where details are missing rather than guessing a rating.

• You have equipment names or photographs: attach them, then use the load schedule to collect the relevant nameplate and manual data.
• You have a specified capacity or proposed model: attach the specification, including frequency and duty, and read the electrical rating before comparing candidates.
• Equipment starts or restarts automatically: describe those events alongside the running loads; use the restart example to show the information needed.

Comparing other genset sizes? The Kyusen genset rental range guide covers Airman, Denyo and Texas 1000kVA references. A catalogue capacity is a discussion point; the supplier and responsible electrical team still need to assess the complete load and duty.

Read the electrical rating, not the engine number

For a 100kVA genset, distinguish apparent electrical power in kVA from real electrical power in kW. Cummins gives the relationship kW = kVA × power factor. Power-factor reference

Kyusen’s Texas catalogue states 100kVA prime, 110kVA standby, 0.8 power factor, 400V, three phase and 50Hz. For the stated prime rating and power factor, 100 × 0.8 = 80kW is the associated real-power figure. This is a calculation from those catalogue fields, not a guarantee that every 80kW load will start or that every 100kVA machine has the same specification. Texas catalogue

The same catalogue separately lists 92kW at 1500rpm under engine prime power. That is an engine-data entry, not a 92kW electrical supply promise. Keep engine output, genset electrical output and the load’s input requirement separate when reading a proposal.

Ask for the exact unit’s electrical kW/kVA rating, voltage, phase, frequency and duty basis. A model name or the words “100kVA generator rental” are not a complete specification.

Keep those duty labels and frequencies with the figures. Ask for the documented operating conditions and assessment of your starting/restart events before comparing suitability. The two references do not establish that any proposed 100kVA unit will supply the same load under the same duty.

Build a schedule of electrical input loads

Caterpillar’s commercial sizing guidance assesses both running demand and starting demand. A list of equipment names without their electrical data leaves the capacity question open. Sizing inputs

Use one entry per equipment type and identify how many units can operate together. Attach clear nameplate photos and the relevant manual pages. Record whether a kW figure describes electrical input, mechanical output or another rating; ask the assessor to resolve anything unclear.

Leave unknown values marked as unknown. Do not assign 0.8 power factor to every load simply because it appears on the generator catalogue. Likewise, a motor’s output rating needs clarification before it is used as a running electrical-input figure.

Describe each starting event and its running baseline

A satisfactory running total does not settle motor starting. Cummins explains that starting performance depends on the complete genset, including its engine and controls. Motor-starting discussion

For each motor, provide the actual starting method and its documented demand. Identify direct-on-line, star-delta, soft-starter or variable-frequency-drive equipment from its documents; do not change the starting arrangement to fit an assumed generator size.

Then state what is already running when that motor starts. The assessor needs an event description as well as a running-load total. Include tools or processes that cycle repeatedly, and note whether the timing is controlled or can overlap. Request assessment against the equipment’s voltage and frequency limits, rather than a universal “multiply motor kW by three” rule.

Test the proposed sequence against later restarts

Cummins discusses controlled load steps and also warns that later, uncontrolled starts may need checking. Its sequence guidance includes exceptions, so there is no universal starting order for every site. Load-step considerations

Illustrative brief: lighting and Pump A are running when Pump B cycles back on. Send the running input of the lighting and Pump A, plus Pump B’s starting data. Also ask what happens if both pumps request a restart after an interruption. This is a planning example, not a recommendation that a particular 100kVA unit can handle the combination.

If staged starting is proposed, ask which controls enforce it, which loads can wait and how later restarts are handled. Record the assessed sequence in the proposal. A spoken intention to “start them one at a time” should not be the only basis where equipment restarts automatically. Have the responsible electrical team confirm any control changes and acceptance criteria.

Keep phase allocation and sensitive loads visible

Cummins recommends distributing single-phase loads across a three-phase supply to limit imbalance. Phase-balance reference

List single-phase equipment separately and ask the electrical team to assess its allocation. A combined site kW total does not describe how the load is distributed. The catalogue’s three-phase rating should not be read as the amount available from one single-phase outlet.

Identify UPS systems, electronic drives, welders and other equipment with special input characteristics. Attach their supplier’s supply-quality and restart requirements. Ask the assessor to include them explicitly in the response; a generic allowance for “miscellaneous equipment” can hide an important requirement.

Match the assessment to the duty and site

State whether the genset will supply routine site work, intermittent work or planned backup, and give the hours and expected operating pattern. Ask which published duty rating is being used for that pattern. Keep the Texas catalogue’s prime and standby entries separate; confirm the actual unit’s rating conditions.

Caterpillar identifies temperature and altitude as site factors that can affect available capacity. Site-condition inputs Provide the site conditions and intended placement, then request any applicable adjustments from the proposed unit’s documentation. Do not apply a fixed Malaysia-wide derating percentage.

Add the distribution layout and connection point for the electrical team’s review. Have that team arrange the connection, protection and switching assessment; this worksheet does not specify cable sizes or installation settings.

Ask for a response tied to your completed schedule

Send the load schedule, documents and event descriptions together. If 100kVA is a project requirement, attach the specification. If it is only a starting point for your enquiry, say so and request a capacity assessment.

The response should identify the proposed genset and duty rating, the load combinations assessed, starting/restart events and the applicable equipment limits. Ask the supplier and electrical team to resolve missing data before booking. Review substitutions against the same schedule, rather than accepting another unit solely because its label also says 100kVA.

Once the technical requirement is clear, use the quotation scope checklist to compare condition, pricing and included services. For rental, request availability and hire terms for your dates. For purchase, choose Purchase in that same form and ask about the offered unit, condition, inspection and sale terms. Keep the assessed load schedule with either proposal; a rental listing is not confirmation of sale stock.