Math & Numbers
Inverse-Time Overcurrent Relay Setting (IEC 60255-151)
Compute the operating time of an inverse-time overcurrent relay per IEC 60255-151: t = TMS·(k/((I/I_s)^α − 1)). Supports Standard Inverse (SI), Very Inverse (VI), Extremely Inverse (EI) and Long-Time Inverse (LTI) curves, and samples a T-I characteristic.
json· JSON resultOpen tool
Quick start
Call this tool from your code in three languages.
cURL
curl -X POST 'https://api.elysiatools.com/en/api/tools/relay-setting-calculator' \
-H 'Content-Type: application/json' \
-d '{"curveType":"SI","pickupCurrent":100,"timeMultiplier":0.2,"faultCurrent":500,"curvePoints":21,"decimalPlaces":4}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
HTTP
POST https://api.elysiatools.com/en/api/tools/relay-setting-calculatorParameters
| Name | Type | Required | Description |
|---|---|---|---|
| curveType | select | No | — |
| pickupCurrent | number | Yes | Relay pickup (setting) current, primary side. |
| timeMultiplier | number | Yes | Time multiplier setting, typical 0.05 – 1.0. |
| faultCurrent | number | Yes | Applied fault current. Must exceed pickup (I > I_s) for the relay to operate. |
| curvePoints | number | No |
MCP integration
Add this tool to your Model Context Protocol server so AI agents can list and call it.
Server configuration
Add this block to your MCP client configuration:
mcp.json
{
"mcpServers": {
"elysiatools-relay-setting-calculator": {
"name": "relay-setting-calculator",
"description": "Compute the operating time of an inverse-time overcurrent relay per IEC 60255-151: t = TMS·(k/((I/I_s)^α − 1)). Supports Standard Inverse (SI), Very Inverse (VI), Extremely Inverse (EI) and Long-Time Inverse (LTI) curves, and samples a T-I characteristic.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=relay-setting-calculator",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
tools/list
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
tools/call
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "relay-setting-calculator",
"arguments": {
"curveType": "SI",
"pickupCurrent": 100,
"timeMultiplier": 0.2,
"faultCurrent": 500,
"curvePoints": 21,
"decimalPlaces": 4
}
}
}Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).
Questions or issues? Contact [email protected]