Does this calculator select a capacitor bank?

No. It compares entered stage sizes with an entered correction requirement and does not select equipment, contactors, detuning or controls.

Where should the required kVAr value come from?

Use a documented power-factor correction worksheet, metering record or engineering note that matches the load condition being reviewed.

Why are stages evaluated in entered order?

The page is a transparent worksheet, so it follows the entered stage order rather than searching every possible equipment combination.

Can unavailable stages be excluded?

Yes. Mark a stage unavailable when it is bypassed, out of service or outside the current staging scenario.

What still needs review after staging?

Harmonic condition, resonance, detuning, switching, manufacturer data, enclosure details and site requirements still need project review.

Capacitor bank staging calculator

Selected kVAr = sum of available entered stages that do not exceed Required kVAr; Remaining = Required kVAr - Selected kVAr; Target check = Remaining <= Target remaining kVAr

Stages are evaluated in the order entered by the user.
Unavailable stages are excluded from the selection set.
The calculator never selects manufacturer equipment or detuning.
Remaining kVAr above the entered target produces a review note.

Formula variables
Variable	Meaning	Unit	Use
Required	Required correction	kVAr	Correction requirement from a separate PF worksheet or metering record.
Stage	Entered capacitor stage	kVAr	One user-entered capacitor stage rating.
Selected	Selected stage total	kVAr	Sum of available entered stages that fit without exceeding Required.
Remaining	Remaining correction	kVAr	Required correction minus Selected.
Target	Target remaining	kVAr	Entered remaining-kVAr value used as the worksheet target.

Capacitor bank staging calculator technical guide

Stage Australian capacitor-bank kVAr steps against an entered power-factor correction requirement and remaining-kVAr target.

Use this calculator when a required correction value already exists and the next question is how entered capacitor stages sit against that requirement. It is useful for Australian project records, switchboard notes and service discussions where the stage values are known but the remaining kVAr needs to be visible.

The page is deliberately a staging worksheet. It does not choose capacitor equipment, tune a bank, check harmonic resonance, set switching controls, confirm detuned reactor data or replace manufacturer selection. Keep the source of the required correction and the stage list with the exported record.

Stage Selection Use Cases

Capacitor stage selection use cases
Work situation	Entered basis	Useful output	Outside the result
Power-factor correction follow-up	Required kVAr from a PF worksheet and available stage sizes	Selected stage total and remaining kVAr	Equipment selection or correction design
Existing bank service note	Stage ratings and unavailable stage markers	Which stages are counted in the worksheet	Service test procedure or switching control settings
Tender comparison	Proposed stage schedule and target remaining kVAr	Transparent stage count and remaining correction	Supplier recommendation or product approval
Facility review	Existing stage list and measured correction requirement	Whether remaining kVAr is within entered target	Harmonic study or resonance assessment
Upgrade planning	Current bank stages and extra stage allowance	Gap between required and selected kVAr	Switchboard enclosure, ventilation or protection design

A strong record names the source of the correction requirement. A weak record only lists stage sizes and leaves the upstream PF calculation, metering period or load condition unclear.

Staging Boundary

Staging boundary
Included in this calculator	Not included in this calculator
Required correction in kVAr	Automatic equipment selection
Four entered capacitor stage values	Harmonic resonance or detuned reactor sizing
Available or unavailable stage state	Manufacturer catalogue interpretation
Selected total, remaining kVAr and stage count	Contactor, fuse, protection or enclosure checks
Review note when remaining kVAr exceeds target	DNSP or site approval decision

The boundary matters because capacitor banks can affect power quality. The arithmetic is simple, but equipment suitability depends on site measurements, manufacturer data, switching arrangement and harmonic conditions.

Input Checklist

Values to collect before staging
Input	Strong basis	Weak basis
Bank reference	Switchboard, correction worksheet or asset ID	Generic note with no site context
Required correction	Current PF calculation, metering study or engineering worksheet	Rounded value with no operating condition
Target remaining	Project or reviewer target for remaining kVAr	Hidden target or no acceptance boundary
Stage sizes	Nameplate, drawing or supplier stage schedule	Remembered stage list without source
Availability	Service state, bypass note or proposed stage state	Assuming every stage is usable

When the required kVAr comes from the power factor correction calculator, keep that exported record with this staging record. If the value comes from metering, record the period, load condition and whether the load was representative.

Review Workflow

Confirm the upstream required correction value and the operating condition behind it.
Enter the capacitor bank reference so the record can be traced to a switchboard, asset or proposal.
Enter each stage size in the order being reviewed.
Mark stages unavailable when they are bypassed, out of service or outside the current scenario.
Enter the target remaining kVAr that defines whether the staged result is close enough for the worksheet.
Read the selected kVAr, remaining kVAr and stage count.
If the remaining kVAr exceeds the target, review the entered stage schedule or the required correction value.
Before equipment work, check manufacturer data, harmonic condition, resonance, switching arrangement and site requirements.

The workflow keeps arithmetic transparent. It is not intended to optimise every possible stage combination or hide a product decision inside a public calculator.

Worked Australian Examples

Capacitor staging examples
Situation	Required correction	Entered stages	Practical reading
Four-step correction record	145 kVAr with 10 kVAr target remaining	50, 50, 25 and 12.5 kVAr	All four stages total 137.5 kVAr, leaving 7.5 kVAr inside the target.
Target range estimate	145 kVAr with 25 kVAr target remaining	50, 50, 25 and 12.5 kVAr	The same staged total sits within the wider target.
Unavailable stage note	95 kVAr with one 30 kVAr stage unavailable	40, 25 and 12.5 kVAr available	The bypassed stage is excluded from the selected set.

These examples show how the same stage list can be read differently when the remaining-kVAr target changes. They do not decide whether the equipment is suitable for the site.

Related Tools

Use the power factor correction calculator when the required kVAr still needs to be estimated from existing and target PF. Use the reactive power kVAr calculator when the source question is the reactive component of a load. Use the power-factor correction planning guide when the task moves from arithmetic to site and equipment context.

Next tool selection
Next question	Use next
Required correction is unknown	Power factor correction calculator
kVAr needs to be derived from kW and PF	Reactive power kVAr calculator
Equipment and site context must be reviewed	Power factor correction planning guide
The tariff impact is the next question	Power factor penalty calculator

Stop Points

The required correction value has no source or operating condition.
Stage ratings are not confirmed from drawings, labels or supplier data.
Harmonic or resonance conditions are material to the site decision.
Switching, contactor, detuning or enclosure details are being inferred from the arithmetic alone.
The record is being used to approve equipment instead of supporting a project review.

Export the result only with the correction source, stage source and review boundary attached. The selected stage total is a worksheet output, not a final capacitor-bank design.

Reference: CAP-STAGE-1
Required correction: 145 kVAr
Target remaining: 10 kVAr
Entered stages: Stage 1 50 kVAr, Stage 2 50 kVAr, Stage 3 25 kVAr, Stage 4 12.5 kVAr

Selected stages4 stage(s)
Selected kVAr137.5 kVAr
Remaining kVAr7.5 kVAr

Selected capacitor stages137.5 kVAr

7.5 kVAr remains against the entered target.

All four entered stages fit without exceeding the requirement, leaving a small remaining kVAr value inside the entered target.

Stages are evaluated in the entered order.
The worksheet does not tune equipment or switching controls.
Harmonic and resonance review remains outside the arithmetic.

Reference: CAP-STAGE-2
Required correction: 145 kVAr
Target remaining: 25 kVAr
Entered stages: Stage 1 50 kVAr, Stage 2 50 kVAr, Stage 3 25 kVAr, Stage 4 12.5 kVAr

Selected stages4 stage(s)
Selected kVAr137.5 kVAr
Remaining kVAr7.5 kVAr

Selected capacitor stages137.5 kVAr

7.5 kVAr remains against the entered target.

The selected stages sit within the entered remaining-kVAr target, so the record can move to equipment review.

Available stages use the entered kVAr values.
The target is a project worksheet value.
Final contactor, detuning and enclosure details are separate checks.

Reference: CAP-STAGE-3
Required correction: 95 kVAr
Target remaining: 15 kVAr
Entered stages: Stage A 40 kVAr, Stage B 30 kVAr, Stage C 25 kVAr, Stage D 12.5 kVAr

Selected stages3 stage(s)
Selected kVAr77.5 kVAr
Remaining kVAr17.5 kVAr

Selected capacitor stages77.5 kVAr

17.5 kVAr remains against the entered target.

Only available stages are considered, so the record shows a remaining value that should be reviewed against the entered target.

Unavailable stages are not included in selected or unused capacity.
The entered required correction comes from a separate power-factor calculation.
Equipment suitability is not decided by this page.