Setting MicroLogic  7.0 A Trip Unit

You can set the tripping curve of your MicroLogic  7.0 A trip unit to match the needs of your installation using the following parameters:

1. Current setting Ir (long time)

2. Time delay tr (long time) for 6 x Ir

3. Pickup Isd (Short time)

4. Time delay tsd (short time)

5. Pickup Ii (instantaneous)

6. Pickup IΔn (earth leakage)

7. Time delay Δt (earth leakage)

Set the Threshold Values

In this example, the rated current In of the circuit breaker is 2000 A.

	Ir = 0.7 x In = 1400 A Isd =2 x Ir = 2800 A Ii = 3 x In = 6000 A IΔn = 1 A	I²t ON curve	I²t OFF curve

Set the Time Delays

In this example, time delay tr of the circuit breaker is 1 second, time delay tsd is 0.2 seconds and time delay Δt = 140 milliseconds

		I²t ON curve	I²t OFF curve