Equal numbers do not establish equal capability
An inverter quoted at 10 kW cannot automatically be equated with one quoted at 10 kVA. First identify what each rating describes. kW measures active power, while kVA measures apparent power in an AC system. Read both values and their conditions rather than treating their unit labels as interchangeable.
Schneider Electric distinguishes active power P, reactive power Q and apparent power S; power factor relates active to apparent power. This article uses magnitudes in one direction, not the positive/negative sign conventions of individual meters. It is not a method of selecting an inverter from a single number.
Use an example to expose missing information
At a hypothetical operating point, apparent power of 10 kVA and power factor of 0.9 correspond to 10 × 0.9 = 9 kW of active power. Conversely, 9 kW at power factor 0.9 corresponds to 9 ÷ 0.9 = 10 kVA. These are illustrative figures, not a product specification or measured project result.
Power factor is not conversion efficiency. The difference between 10 kVA and 9 kW is not a 1 kW energy loss. Nor should the whole building’s load power factor simply be multiplied by an inverter’s rating, especially for a grid-connected unit with its own control modes. Ask the designer to identify the measurement point and operating mode.
Separate continuous ratings from maximum values
Obtain the exact model and variant datasheet. Record rated active power, maximum apparent power, power-factor range and stated conditions such as temperature, voltage or mode. Mark missing information as unconfirmed rather than borrowing from a similar model. A maximum figure alone does not establish continuous operating duration.
Separate PV-input ratings from AC-output ratings, and grid-connected from backup mode where applicable. A PV array larger than the AC rating does not establish that the inverter can deliver the entire array rating. Motor starting and backup duration introduce further limits; the power-factor calculation does not replace those checks.
Compare quotations on a consistent basis
Build one row per model with the document field name, value, unit, mode, conditions and source page. Ask each supplier which figure supports the intended load. Two hypothetical units may both say 10 kVA yet differ in continuous active power or temperature conditions; price per kVA alone would not make them equivalent choices.
For a discussion with Kintury Energy, bring complete quotations, load and operating-time information, and existing measurements. Measurements inside electrical panels require competent personnel and suitable equipment. Do not change power-factor settings or circuits to match a quotation. The comparison should identify verified limits and unresolved questions, not promise that a higher rating always provides better value.
