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

instrument mechanism / verified-clean

# Induction Motor Slip & Speed Calculator mechanism

The inspectable method record for Induction Motor Slip & Speed Calculator, kept separate from implementation and qualification.

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

## Model scope

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.

- 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.

## Units and conventions

- 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.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "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."
}
````

## Failure boundary

**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.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/induction-motor-slip-speed-calculator/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`

- `BOUNDARY_HAZARD_CATALOG.json`