U-EK230E
L-BAL-E185-GB 2023/10 Index 005
11660-0711-03
3/12
4
Application and brief description
The device protects electrical equipment against excessive warming and thermal overload. Used in
combination with respective thermistors tripping temperatures from 60 °C up to 180 °C can be realized.
The device is conform to EN 60947-8. Thermistors according to DIN VDE V 0898-1-401 (ATEX) or
equivalent detail specification (UKEX) shall be connected. The thermistors are suitable for installation
into windings of electrical machines or transformers, bearings and heatsinks as well as to monitor the
temperature of liquid media, airflow and gases. With ATEX approval, equipment in explosive gas
atmospheres Zone 1 and 2 (marking G: gas) or in areas with combustible dust Zone 21 and 22 (marking
D: dust) can be protected. All functions of the device serve to protect non-explosive-protected equipment
and explosive-protected equipment in regular operation and in case of failure.
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Summary of features
•
1 thermistor circuit for 1 (not allowed for explosive atmospheres), 3 or 6 PTC thermistors
“TP”.
•
Short-circuit detection within the thermistor circuit.
•
Output relay with 1 change-over contact (co).
•
Operating status display.
A current monitors continuously the resistance of the thermistor circuit. In cold state, the resistance is
≤ 250 Ω per thermistor (thermistor circuit ≤ 1.5 kΩ). The device is switched on and relay contacts 11, 14
are closed. The resistance of the thermistors rises rapidly at detector operating temperature TNF. The
device switches off at a
resistance of 3…4 kΩ and the relay contacts 11, 12 close. The device also
switches off in the case of detector or line short-circuit (< approx. 20
Ω) or detector or line interruption.
The device remains switched off until the build in or an external reset button is pushed. Power-on is
recognized as reset. With bridged terminals Y1, Y2, the reclosing lock function is disabled.
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Connecting diagram
Us
Supply voltage
S1
Off switch
1) external interlock,
see chapter 15.11
Manual reset
TP
PTC thermistor
S2
Push button on
(manual reset)
F1
– F4 Fuses
S3
Remote reset
H1
Indicator lamp fault
K1
Contactor
