Verified calculation capability

Electric power Calculation Capability

Real power in watts from V×I×PF (DC / 1φ / balanced 3φ L-L), from I²R, or average power E/Δt. PF=0 is valid (P=0); blank PF defaults to 1. Δt=0 is INVALID_TIME_INTERVAL. · Electrical

Capability ID electrical.power · version 1.3.0

Open calculator REST API MCP Evidence Evidence JSON Review policy

Model

DC / resistive

DC / resistive: P = V × I
AC 1φ: P = V × I × PF
AC 3φ (L-L): P = √3 × V × I × PF
With resistance: P = I²R
Energy: P = E / Δt

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

Symbol	Quantity	Unit	Role
`formula`	—	—	output
`api_version`	—	—	output
`api_contract_version`	—	—	output
`spec_version`	—	—	output
`page`	Canonical calculator page URL	—	output
`links`	—	—	output

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

Three-phase path uses balanced line-to-line RMS voltage.
PF on the V×I path is total power factor λ = |P|/S in [0, 1]; blank PF defaults to 1.
I²R path assumes resistive power dissipation (I + R inputs). V²/R is the Ohm’s-law identity, not a third tab.
Energy path is average power P = E/Δt with Δt > 0.

Example

One numerical check. The calculator page holds worked steps and FAQ.

230 V × 10 A × 1 (1φ) = 2300 W

Open this example in the calculator

Trust

Review-policy: engine tested — automated tests, sources, version lock, and evidence published. Supplemental to CVP; not Domain Expert Review. See CVP and Review policy.

Tier: Engine tested — catalog token engine_tested
Calculation version: 1.3.0
Evidence tests: 26/26 calculation tests · golden 14/14 · boundary 7/7 · property 5/5
Engine tested: Yes
Source checked: Yes
Supplemental domain review: Not performed
Named expert review: Not performed
Version lock: Supported (409 VERSION_MISMATCH)
Artifact consistency: Build verified · 1.3.0 (workspace artifacts agree)

Production attestation: Embedded snapshot: STALE · Last attested schema matched 1.3.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-16T06:44:24.909Z
Semantic contract: PASS
Evidence attested at: 2026-09-16T06:44:24.203Z
Last production check: 2026-09-16T06:44:24.203Z
Public / cache: PASS
Origin: PASS

Call this capability

Human page, REST, and MCP share the same engine and calculation_version. Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Production surface contract 1/1.

Tool id: power
Engine: electric-power
REST: POST /api/v1/calc/power
MCP: execute_calculation with capability_id: "electrical.power"
Agent input schema: Canonical (MCP / Agent)
REST input schema: Compatibility (tol[] / tol1…)
Output schema: JSON Schema (latest)
Versioned input schema: Immutable pin (1.3.0)
Versioned output schema: Immutable pin (1.3.0)

Operations

Declared calculation modes for this capability.

power-vi
power-ir
power-energy
vi_dc
vi_ac_single
vi_ac_three_phase_ll
i2r
energy_average

References

Human-readable sources plus CVP reference evidence classes.

Sources

Watt’s law / power identity — Real power P = V × I × PF (1φ); P = √3 × V × I × PF (3φ L-L)
Joule heating / Ohm’s law forms — P = I²R = V²/R for resistive dissipation
Energy–power relation — Average power P = E / Δt (J/s → W)
IEC 60050 — International Electrotechnical Vocabulary — Active power (IEV 131-11-42)
IEC 60050 — International Electrotechnical Vocabulary — Power factor (IEV 131-11-46)
IEEE Std 1459-2025 — Power factor and real vs apparent power
BIPM SI Brochure (9th edition, version 4.01) — SI units for watt, volt, ampere, and joule
NIST Guide to the SI (SP 811) — Watt as joule per second

Try with an agent

Inspect this capability via same-origin MCP, then call execute_calculation.

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: inspect_capability' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"electrical.power"}}}'

Inspect the trust tier and required assurance level before execution. Pin calculation_version (1.3.0) when reproducibility matters. Full protocol notes: MCP docs.