Short and Long DIPS-SAG testing
Dips on mains voltage
Electrical and electronic equipment may be affected by voltage dips and short interruptions. By connecting this equipment to low-voltage power supply networks, they are subject to this type of disturbance. Voltage dips and short interruptions are caused by faults in the network, in installations or by a sudden large change of load. In certain cases, two or more consecutive dips or interruptions may occur.
These phenomena are random in nature and can be characterized in terms of the deviation from the rated voltage and duration. Most data-processing equipment has built-in power-fail detectors in order to protect and save the data in the internal memory so that after the mains voltage has been restored, the equipment will start up in the correct way. Some power-fail detectors will not react sufficiently fast on a gradual decrease of the mains voltage. Therefore, the d.c. voltage to the integrated circuits will decrease to a level below the minimum operation voltage before the power-fail detector is activated and data will be lost or distorted. When the mains voltage is restored, the data-processing equipment will not be able to restart correctly before it has been re-programmed.
When performing the tests it is required that the EUT and possible auxiliary equipment are exercising all normal modes of operation. The test results may be classified on the basis of the operating conditions and functional specifications of the EUT, according to the following performance criteria:
- (A) Normal performance within the specification limits;
- (B) Temporary degradation or loss of function or performance which is self-recoverable;
- (C) Temporary degradation or loss of function or performance which requires operator intervention or system reset;
- (D) Temporary degradation or loss of function or performance which is not recoverable, due to damage of equipment (components) or software, or loss of data.
