Standard Test Method for TemperatureRise of Automotive Components

I. Test Equipment and Tools

Required equipment: highcurrent DC constantcurrent source, multichannel temperature recorder, TypeK thermocouples, calibrated torque wrench, hightemperatureresistant PI tape, lintfree cloths, standard currentcarrying cables, sample fixing fixture, ambient temperaturehumidity meter. All instruments shall be within valid calibration period. The power supply shall feature low ripple and stable current output.

II. Test Environment Requirements

The test ambient temperature shall be controlled at 23 ℃ ± 5 ℃ with natural convection. No direct airconditioning blowing, direct sunlight exposure or interference from external heat sources shall be present. The sample shall be mounted in exactly the same orientation as in vehicle assembly. Arbitrary tilting, suspension or installation of additional heatdissipation structures are prohibited, so as not to alter the actual heatdissipation conditions.

III. Sample Assembly and Pretest Preparation

Inspect the sample for no damage, oxidation or deformation on its appearance. Tighten the wiring terminals and busbar bolts to the torque values specified in the drawing to avoid poor contact. Dedicated cables with currentcarrying capacity of at least 1.5 times the test current shall be adopted for the test circuit, to prevent heat generation of the leads themselves from interfering with test data. Record the ambient temperature before test, and measure the initial contact resistance of each connection point with a microohmmeter.

Thermocouple Layout Method

Measurement points shall be preferentially arranged at core heatsource locations: terminal mating contact surfaces, wire crimping points, bolt fastening positions, busbar joints, plastic housing, and ambient reference points. Secure thermocouples tightly with hightemperatureresistant PI tape. Arrange and fix thermocouple leads to prevent pulling stress and shortcircuit.

V. Poweron Test Procedure

Switch on the temperature recorder and set the sampling interval to 60 seconds.

Ramp up the output current of the DC constantcurrent source to the test current (e.g. 300 A for a onehour test duration).

Keep continuous poweron operation, monitor the realtime variation of temperature curves, and collect temperature data of all measurement points without interruption.

Thermal steadystate judgment (automotive industry standard): Thermal steadystate is achieved when the temperature variation of all measurement points is ≤ 1 ℃ within 30 consecutive minutes. Maintain poweron with stable voltage for another 30 minutes after reaching steadystate, and record the final steadystate temperatures.

VI. Poweroff and Posttest Inspection

Cut off the current output upon completion of the test. Remeasure the contact resistance at each connection point and compare the resistance change before and after the test. Inspect the appearance of the sample for abnormalities such as blackening, ablation, deformation, plastic softening, odd odor and arcing.

VII. Data Calculation and Judgment

Temperature rise = Steadystate temperature of measurement point − Simultaneous ambient temperature. The temperature rise of all measurement points shall comply with the limit values specified in national standards, enterprise standards or component specifications. The test is deemed passed if there is no overtemperature, thermal runaway, visual damage, and no abnormal increase of contact resistance.

AMASS High current connector widely used in the internal battery, motor, and electrical control connections.