Source: https://guthlabs.ai/docs/instruments/power-factor-correction-capacitor-sizer/implementation/

instrument implementation / implementation-contract

# Power Factor Correction Capacitor Sizer implementation

A source-bound implementation contract for Power Factor Correction Capacitor Sizer; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t4-030

**Effect**: Computation or source lookup only

## Input and validation requirements

The instrument has an undefined-result failure at target_PF=0 because tan(acos(target_PF)) diverges. It also has a potentially threefold sizing error unless three-phase power, line-to-line voltage, and per-phase versus total-bank capacitance conventions are made explicit.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "load_kW": 10,
    "existing_PF": 0.8,
    "target_PF": 0.95,
    "V_V": 230,
    "f_Hz": 50,
    "phases": 1,
    "connection": "single-phase"
  },
  "expected_outputs": {
    "required_kVAR": 4.213159,
    "capacitance_per_phase_F": 0.000253514,
    "capacitance_per_phase_uF": 253.514,
    "new_PF": 0.95
  },
  "working": "θ1=acos(0.8), so tanθ1=sqrt(1−0.8²)/0.8=sqrt(0.36)/0.8=0.6/0.8=0.75. θ2=acos(0.95), so tanθ2=sqrt(1−0.95²)/0.95=sqrt(0.0975)/0.95=0.328684. Qc=10×(0.75−0.328684)=4.213159 kVAR. Convert to VAR: 4.213159×1000=4213.159 VAR. C=4213.159/(2π×50×230²)=4213.159/(2π×50×52900)=4213.159/16619025.119=0.000253514 F=253.514 µF. With ideal exact correction, new PF=0.95."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/power-factor-correction-capacitor-sizer/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/power-factor-correction-capacitor-sizer/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/power-factor-correction-capacitor-sizer/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`