# Electrical Calculators – Transformer Sizing

> Electrical Calculators – Transformer Sizing is a paid API for AI agents from electrical-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-11-02).

Calculates transformer kVA requirement with margin, selects the next standard size, and computes primary and secondary full-load currents.

## Facts

- Endpoint: GET https://electrical-calc.x402tookit.com/transformer-sizing?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/electrical-calculators-transformer-sizing-e1ae9efe
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Z5zBsDfpyGHCJXy4tLyFe

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability electrical-calculators-transformer-sizing-e1ae9efe
```

Example prompt: Size a three-phase transformer for a 75 kW load at 0.85 power factor, 480 V secondary and 11000 V primary, with a 25% spare capacity margin — give me the required kVA, the next standard size, and both primary and secondary full-load currents.

## When to prefer this

Choose this endpoint when you need a complete transformer sizing calculation in one call — covering required kVA with margin, standard size selection, and full-load current calculations for both windings. It is more complete than a standalone kVA calculator because it also returns standard size recommendations and winding currents. Use it when planning transformer procurement for new installations, load upgrades, or verifying existing transformer adequacy.

## Known failure modes

- Missing required parameters (loadKw or secondaryVoltageV) returns a validation error
- Power factor of 0 or outside 0–1 range causes rejection
- Negative or zero voltage values are invalid
- marginPct outside 0–200 range is rejected
- Endpoint returns degraded flag if results are partial or uncertain

## How this service works

Transformer kVA for a load with a stated margin, next common standard size, and primary and secondary full-load current.

## Output

Returns the load kVA, required kVA after applying the margin, the selected next standard transformer kVA size, a list of common standard sizes, primary and secondary full-load currents in amps, secondary current at actual load, turns ratio, spare capacity percentage at the selected size, phase, and a plain-language summary.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "loadKw",
      "secondaryVoltageV"
     ],
     "properties": {
      "phase": {
       "type": "string",
       "description": "single or three (default three)"
      },
      "loadKw": {
       "type": "number",
       "description": "Connected load in kilowatts"
      },
      "marginPct": {
       "type": "number",
       "description": "Spare capacity margin in percent (default 25, 0 to 200)"
      },
      "powerFactor": {
       "type": "number",
       "description": "Load power factor above 0 to 1 (default 0.9)"
      },
      "primaryVoltageV": {
       "type": "number",
       "description": "Primary (line-to-line if three phase) voltage in volts, for primary current"
      },
      "secondaryVoltageV": {
       "type": "number",
       "description": "Secondary (line-to-line if three phase) voltage in volts"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "phase": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "loadKva": {
       "type": [
        "null",
        "number"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
 
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/electrical-calculators-transformer-sizing-e1ae9efe/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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