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
active electronic current limitation and well-proven circuit breaker
technology including physical isolation.
Technical data (T
= 25 °C, U = DC – 24 V)
B
amb
Operating data
Operating voltage UB
Current ratings IN
DC 24 V (18...30 V)
The max. possible overcurrent is limited to typically 1.2 times rated
current (see table 1). This allows switching on capacitive loads of up
to 40,000 µF, but a disconnection will only be effected in the event of
an overload or short circuit. For adjustment to the load conditions the
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.
fixed rating:
Types ESS31-TC-…:
0.5 A, 1 A, 2 A, 3 A, 3.6 A, 4 A,
6 A, 8 A, 10 A, 12 A
Standby current I0
depending on the
signal output
in ON condition: typically 8 mA
Trip current (bimetal)
typically 0.4 A
(only in the event of a failure, until physical
disconnection)
As soon as the ESS31-T detects an overload or short circuit in its
load circuit, it blocks the load output transistor and disconnects the
current flow in the faulty circuit. After remedy of the failure, the load
output of the ESS31-T is re-activated manually by actuating the ON/
OFF switch of the device.
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Visual status
indication
multicoloured LED:
Green:
- device is ON (S1 = ON)
load circuit connected
Orange:
- overload or short circuit until
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US patent number: US 6,490,141 B2
US patent number: US 8,237,311 B2
electronic disconnection
Red:
- device switched OFF electronically
load circuit OFF
- undervoltage (UB < 8 V)
Features and Benefits
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Selective load protection with physical isolation
in the event of a failure
All types of loads can be connected
(DC 24 V motors upon request)
Active current limitation when switching on capacitive loads
up to 40,000 µF and in case of overload/short circuit
Fixed current ratings from 0.5 A to 12 A
Reliable overload disconnection typically from 1.2 x IN even with
OFF:
- manually OFF (S1 = OFF)
load circuit physically isolated
or device is dead-voltage
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Potential-free signal contact
On/off position of the switch S1
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Load circuit
long load lines or small cable cross sections
Manuel ON/OFF switch (push-push actuation)
Clear status indication by means of LED
Integral fail-safe element, adjusted to current rating
Width per channel only 12.5 mm
For direct rail mounting
Ease of wiring via entry line busbars LINE+ and 0 V
Load output
power MOSFET switching output
(plus switching)
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Overload and short
circuit disconnection
typically 1.2 x IN
with active current limitation
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Trip times for
electronic disconnection
see time/current characteristic
overload trip time typically 500 ms
short circuit trip time depending on
current rating (see table 1)
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for physical isolation
typically 5 s
Approvals ESS31-TC
Temperature disconnection internal temperature monitoring
with physical isolation
Approval
authority
Standard
Rated voltage
Current ratings
Undervoltage
monitoring
with hysteresis, no reset required:
»OFF« at UB < 14 V
of load output
»ON« at UB > 17 V
VDE
UL
EN 60934
UL 1077
DC 30 V
DC 30 V
0.5 A…12 A
0.5 A…12 A
Switch-on delay tStart
typically 2 ms after each ON operation,
reset and after applying of UB
Capacitive loads
up to 40,000 µF
Free-wheeling diode
external free-wheeling diode
recommended for inductive load
1646
www.e-t-a.de
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