Connector Contact Resistance and Temperature Rise Estimator

I²R heating of a contact and an estimate of its temperature rise from the datasheet rating or a thermal resistance.

Inputs

Current per contact (A) Contact resistance (mΩ) Contacts carrying this current Ambient temperature (°C) Maximum operating temperature of the connector (°C)

Method A — scale the datasheet rating

Datasheet rated current (A) Temperature rise at rated current (K)

Method B — thermal resistance

Thermal resistance contact-to-ambient (K/W)

Results

Method A assumes temperature rise is proportional to I² (ΔT = ΔT_rated × (I / I_rated)²), the basis of the temperature-rise derating test in IEC 60512-5-2. Take rated current and ΔT from the datasheet; the result is an estimate, and mounting, neighbouring contacts and airflow change it.

For preliminary assessment only — the final decision must follow the manufacturer’s datasheet and the applicable NEC / IEC / UL standards. Results are calculated from the standard formulas stated on this page and are for design estimates only. They are not a rating of any specific part — always confirm current, voltage, temperature and environment limits against the manufacturer’s datasheet for the part you intend to use.

Need help with a connector?

Tell us what you are designing — our engineers can suggest series and second-source options.

← All tools