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EntelliGuard* L

Short-circuit Protections, I, HIOSC & MCR

Instantaneous Short-circuit (I) Protection
A user settable device that allows a high speed
fault interruption at a pre-determined current
level. This device can be used with the short time
delayed (ST) short-circuit protection device or as
replacement thereof. The device has a current METER BREAKER PICKUP
Electronic Trip Units On breakers with a rating of more than 4000A the STATUS x le
adjustment of 2 to 15 (±10%) times the chosen
SET UP
INST
RATING
Primary Current Value (Ie) in steps of 0.5.
The device can also be switched OFF.
1000A
2
maximum setting of 15 x is in some cases limited to
a lower value due to the breaker current rating and
EVENTS
its Short-circuit withstand value (see page B.11).
The Instantaneous tripping system used in
the EntelliGuard Electronic Trip Unit has a
unique programming feature that waits for the
downstream device to trip before reacting to an
overcurrent fault. This providing the user with a
I - Protection Device
unique combination of Speed and Selectivity. 1 - Time Current Curve
Intro The graph indicates the maximum interruption time
and non tripping time across the full current setting
band and the trasnition to the HIOS protection device.
A

HSIOC Protection device 0,1
B To prevent very hi level short-circuit currents
causing damage to their electrical installation
and their components EntelliGuard Power Circuit
C Breaker are equipped with a HSIOC protection
device.
HSIOC - Protection Device
This hi level short-circuit device is installed in all
D EntelliGuard L Breakers and is designed to trip the
breaker at the specified Icw value of the device).
The device, interrupts and thus limits the duration 0,01
of these high level short-circuits to 40 milliseconds.
E

Making Current (MCR) Protection device
X If a breaker is closed on to a short-circuit current it Tripping Time in Seconds (S)
is mandatory that the device interrupts before the
electrical installation and it’s components incur any
damage .

An MCR device is present in all EntelliGuard Power 0,001 0 , 1 0 1 0 , 0 0 1 0 0 , 0 0
Circuit Breakers) specifically designed to trip the
breaker when closing onto a fault. x Breaker Rating (In)
GTU B3 I settings.xls 08-05-2008

B.6