Protective relay (Relay Protection) is an electromechanical apparatus, often with more than one coil, designed to calculate operating conditions on an electrical circuit and trip circuit breakers when a fault is detected (wikipedia).
ANSI Code for Protection
CURRENT PROTECTION FUNCTIONS
• ANSI 50/51 – Phase overcurrent
• ANSI 50N/51N or 50G/51G – Earth fault or sensitive earth fault
• ANSI 50BF – Breaker failure
• ANSI 46 -Negative sequence / unbalance
• ANSI 49RMS – Thermal overload
DIRECTIONAL POWER PROTECTION FUNCTIONS
• ANSI 32P – Directional active overpower
• ANSI 32Q/40 – Directional reactive overpower
VOLTAGE PROTECTION FUNCTIONS
• ANSI 27D – Positive sequence undervoltage
• ANSI 27R – Remanent undervoltage
• ANSI 27 – Phase-to-phase undervoltage
• ANSI 59 – Phase-to-phase overvoltage
• ANSI 59N – Neutral voltage displacement
• ANSI 47 – Negative sequence voltage
• ANSI 79 – Reclose the circuit breaker after tripping
DIRECTIONAL CURRENT PROTECTION
• ANSI 67 – Directional phase overcurrent
• ANSI 67N/67NC – Directional earth fault
• ANSI 67N/67NC type 1
• ANSI 67N/67NC type 2
• ANSI 67N/67NC type 3
MACHINE PROTECTION FUNCTIONS
• ANSI 37 – Phase undercurrent
• ANSI 48/51LR/14 – Locked rotor / excessive starting time
• ANSI 66 – Starts per hour
• ANSI 50V/51V – Voltage-restrained overcurrent
• ANSI 26/63 – Thermostat, Buchholz, gas, pressure, temperature detection
• ANSI 38/49T – Temperature monitoring by RTD
FREQUENCY PROTECTION FUNCTIONS
• ANSI 81H – Overfrequency
• ANSI 81L – Underfrequency
• ANSI 81R – Rate of change of frequency (ROCOF)
Relay protection test! Prevent your electrical distribution systems and those supply before failure.
MDE team experienced in testing of protective relay. Some of the equipment we tested are, SEPAM, GE Multilin, MICOM, SIPROTECT, SPAJ and many more.
We offer test for protective relay by contract schedule and one shoot testing.
Please contact us for Inquiry.
The high voltage test (also called dielectric strength test or hipot test) can be made in AC or DC. If the high voltage test is made in DC, it is then combined with insulation ; if the high voltage test is made in AC, it is then, this is then, more stressful for the sample and made according to the sketch below.
Measurement of high voltage test under alternating current is performed using an alternating voltage (50Hz) adjustable to an effective 50V to 1,500V. As is the case with direct current, the high voltage test detects any sudden rise of current up to a programmed threshold.
The short circuit test is maintained by default. The rise time is more than 500 ms and the application time at least one period.
Warning: The high voltage test under alternating current is penalised by the capacitive value of the tested equipment. It must be remembered that the generator power is limited to 5 mA.