Application
High-temperature continuous operation of electric water pumps
In this high-temperature endurance test, six coolant pumps for automotive applications were tested for their durability at media temperatures of up to 140 °C and ambient temperatures of 125 °C at different voltage levels (U_min, U_nom and U_max) (so-called high temperature degradation). A demanding speed profile was transferred from the vehicle to the test bench.
Requirements for the High-Temperature Degradation Test
Before the actual start of the test, the test specimens were pre-aged for several days at an ambient and media temperature of -25 °C with the same speed profile as in the endurance test itself.
The operating points of the test specimens were set before the start of the endurance test in order to make changes in the pump properties due to the load as visible as possible. To ensure that cross-influences between the DUTs could be ruled out, a separate fluid circuit was provided for each test item and each pump was operated with its own power supply.
In this test run, particular attention was paid to the use of a special medium. In order not to falsify the following cooling water tests, the test circuits were separated from the test bench or system media via individual heat exchangers. Furthermore, the pumps were installed in the exact vehicle installation position at the customer's request.
Monitoring and measurement variables
- Inlet pressure and differential pressure measurement
- Inlet and outlet temperatures of the individual pumps
- Ambient temperature
- Current and voltage measurement of the test items
- Bus communication return values
