Page 56 - Sace Emax 2 Catalogue

t
t
steady
state
t
100% 200%
S
t
I7
t
t7
I4
steady
t 3/32 50% 150% I7 t4 L start-up t7 I I I I I I SACE EMA X 2 LOW VOLTAGE AIR CIRCUIT-BRE AKERS
state start-up
t
— I3 I
50% 150%scription of protection functions
De I
t
100% 200%
L
t S
I
I2
t2 I
t I
t t I4 Overload (L - ANSI 49): available with three different types of trip curve:
2
I1 t4 1. t = k/l with inverse long time;
I7 t1 2. IDMT in accordance with 60255-151 for coordination with medium voltage protections, that are
I available according to the Standard Inverse (SI), Very Inverse (VI) and Extremely Inverse (EI) curves;
t7 3. with t = k/l curve for better coordination with upstream circuit-breakers or with fuses.
4
t I I The thresholds can be fine tuned (for example 1A for circuit-breaker E1.2 1000A) and the timings to the
second can be set directly from the display. The settable pre-alarm indicates the set threshold is
I3
t steady reached before the protection is tripped. The protection can be disabled by rating plug L=off.
state start-up
I
Time-delayed overcurrent (S - ANSI 51 & 50TD): with constant tripping time (t = k), or with constant
t I
specific let-through energy (t = k/l ), this provides 15 current thresholds and 8 curves, for fine adjust-
2
ment. The function can be excluded by setting the dip switch combination to “OFF”.
t I2 100% 200%
50% 150%
t t2 L
S I
I7
I
t t7 I
t I1 I Thermal memory: for L and S protection functions, this is used to protect components, such as trans-
t1 formers, from overheating following an overload. The function, which can be enabled by the Ekip Con-
L
t cold curve nect software, adjusts the protection tripping time according to the length of time that has elapsed
t steady
state start-up since the first overload, taking into account the amount of heat generated.
I4 S
hot curve t4 I
I
I
I
t Instantaneous overcurrent (l - ANSI 50): with tripping curve without intentional delay, it offers 15 trip-
ping thresholds and can be excluded by setting the dip switch combination to “OFF”.
t 100% 200%
50% 150% I3
L
Closing on short-circuit (MCR): the protection uses the same algorithm of the protection l, limiting
S operation to a settable time window from the closing of the circuit-breaker. The protection can be
I I disabled, also alternatively to protection l. The function is active with an auxiliary supply.
I
t

t Earth fault (G - ANSI 51N & 50NTD): with tripping time independent of current (t = k) or constant spe-
2
I2 cific let-through energy (t = k/l ). The function can be excluded by setting the dip switch combination
t2 to “OFF”.
I4
t4 I
I
t
t I1
t1
t Programmable instantaneous overcurrent (2I - ANSI 50): Second instantaneous tripping curve de-
I3 signed to mitigate against arc flashes (also referred to as RELT - Reduced Energy Let-Through). This
I3 protection can be adjusted from 1.5 to 15 x In, with a maximum setting of 18kA. The clearing time of the
I 2I protection is between 25 and 42ms at 60Hz (+5ms for 50Hz). Note: Easy activation and I/O assign-
I ment, including positive feedback, can be implemented using the RELT Ekip Signalling 2K-3 module.
I
t

I2
t2
I

t
I1
t1

I