ESS31-T Datasheet, PDF (1/8 Pages) ETAL Group – Selective load protection with physical isolation in the event of a failure

Electronic circuit breaker ESS31-T...-DC 24 V
Description
The model ESS31-T extends our product group of electronic over-
current protection devices for DC 24 V applications. At a width of
only 12.5 mm it provides selective protection for all DC 24 V load
circuits. This is achieved by a combination of active electronic current
limitation in the event of a short circuit and overload disconnection
at typically 1.2 times rated current. The ESS31-T is track-mountable
and provides ease of installation for groups of devices with several
circuits. DC 24 V switch-mode power supplies are widely used in
automation today. In the event of an overload, however, they turn
down the output voltage which is intended to power all connected
loads. So if there is a failure in a single load of the system, the supply
voltage will break down also in all other load circuits. Not only does
this frequently cause undefined fault conditions, but it can even lead
to machine stoppages or system downtimes.
ESS31-T
In this context selectivity means that type ESS31-T responds faster
to any overload or short circuit conditions in a load circuit than the
switch-mode power supply. This is ensured by the combination of
Technical data (T_amb = 25 °C, U_B = DC – 24 V)
active electronic current limitation and well-proven circuit breaker
technology including physical isolation.
Operating data
Operating voltage U_B
DC 24 V (18...30 V)
The max. possible overcurrent is limited to typically 1.2 times rated Current ratings I_N
current (see table 1). This allows switching on capacitive loads of up
fixed rating:
Types ESS31-TC-…:
to 40,000 µF, but a disconnection will only be effected in the event of _{ 0.5 A, 1 A, 2 A, 3 A, 3.6 A, 4 A,}
an overload or short circuit. For adjustment to the load conditions the
6 A, 8 A, 10 A, 12 A
current rating can be selected in fixed values from 0.5 A to 12 A. Visual
status indication is by means of a multicoloured LED and by integral
signal outputs. The manual ON/OFF switch on the device itself allows
start-up of certain individual load circuits and reset after disconnec-
tion on grounds of overcurrent.
Standby current I₀
depending on the
signal output
Trip current (bimetal)
in ON condition: typically 8 mA
typically 0.4 A
(only in the event of a failure, until physical
As soon as the ESS31-T detects an overload or short circuit in its
disconnection)
load circuit, it blocks the load output transistor and disconnects the Visual status
l multicoloured LED:
current flow in the faulty circuit. After remedy of the failure, the load indication
Green:
output of the ESS31-T is re-activated manually by actuating the ON/ - device is ON (S1 = ON)
OFF switch of the device.
load circuit connected
US patent number: US 6,490,141 B2

Orange:
4
- overload or short circuit until
US patent number: US 8,237,311 B2
electronic disconnection
Features and Benefits
l Selective load protection with physical isolation
in the event of a failure
l All types of loads can be connected
(DC 24 V motors upon request)
l Active current limitation when switching on capacitive loads
up to 40,000 µF and in case of overload/short circuit
l Fixed current ratings from 0.5 A to 12 A
l Reliable overload disconnection typically from 1.2 x I_N even with
long load lines or small cable cross sections
l Manuel ON/OFF switch (push-push actuation)
l Clear status indication by means of LED
l Integral fail-safe element, adjusted to current rating
l Width per channel only 12.5 mm
l For direct rail mounting
l Ease of wiring via entry line busbars LINE+ and 0 V

Red:
- device switched OFF electronically
load circuit OFF
- undervoltage (U_B < 8 V)

OFF:
- manually OFF (S1 = OFF)
load circuit physically isolated
or device is dead-voltage


l Potential-free signal contact
l On/off position of the switch S1
Load circuit
Load output power MOSFET switching output
(plus switching)
Overload and short typically 1.2 x I_N
circuit disconnection with active current limitation
Trip times for see time/current characteristic
electronic disconnection overload trip time typically 500 ms
short circuit trip time depending on
current rating (see table 1)
Approvals ESS31-TC
Approval
authority
VDE
UL
Standard Rated voltage Current ratings
EN 60934
UL 1077
DC 30 V
DC 30 V
0.5 A…12 A
0.5 A…12 A
for physical isolation typically 5 s
Temperature disconnection internal temperature monitoring
with physical isolation
Undervoltage with hysteresis, no reset required:
monitoring »OFF« at U_B < 14 V
of load output »ON« at U_B > 17 V
Switch-on delay t_Start typically 2 ms after each ON operation,
reset and after applying of U_B
Capacitive loads up to 40,000 µF
Free-wheeling diode  external free-wheeling diode
recommended for inductive load
1646
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