Source: https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/

instrument / verified-clean

# Induction Motor Slip & Speed Calculator

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

**Tranche**: tranche-4

**Evidence ID**: t4-078

**Ledger rows**: 1

No ledger note is attached.

## Review findings

Core formulas are standard under the stated unit assumptions, but the specification is ambiguous because input units and pole-count meaning are not explicitly declared. The formula/output mismatch for slip percentage must be corrected or documented. The honest_label field is empty; it should disclose the Hz/rpm assumptions, positive-even pole-count requirement, percentage conversion, and behavior for zero frequency or overspeed.

### Formula and scope findings

- The synchronous-speed formula Ns=120f/P is standard when f is in Hz and P is the total number of poles, producing Ns in rpm.

- The slip formula (Ns−Nr)/Ns is standard and returns a dimensionless fraction, but the declared output is slip %, so the displayed percentage must be 100×(Ns−Nr)/Ns.

- The rotor-frequency formula fr=slip·f is correct only when slip is the fractional value, not the displayed percentage value.

### Unit assumptions

- Frequency f must be specified in hertz (Hz).

- Pole count P means total stator pole count and should be a positive even integer.

- Rotor speed Nr must be specified in revolutions per minute (rpm), matching Ns.

- Ns is reported in rpm, slip is internally a fraction and externally a percentage, and fr is reported in Hz.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

A zero pole count produces division by zero in the synchronous-speed formula, so the calculator must reject that input. The specification does not state validation behavior, creating a potential undefined, Infinity, or NaN result.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "frequency_Hz": 50,
    "pole_count": 4,
    "rotor_speed_rpm": 1440
  },
  "expected_outputs": {
    "Ns_rpm": 1500,
    "slip_percent": 4,
    "rotor_frequency_Hz": 2
  },
  "working": "Ns = 120×50÷4 = 6000÷4 = 1500 rpm. Slip fraction = (1500−1440)÷1500 = 60÷1500 = 0.04. Slip percent = 0.04×100 = 4%. Rotor frequency = 0.04×50 = 2 Hz."
}
````

## Related workflows

[Motor & Drivetrain BenchAC speed](<https://guthlabs.ai/docs/instrument-workflows/motor-drive/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

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

- `BOUNDARY_HAZARD_CATALOG.json`