ETM / ETM2 / ETM22 motor thermal protection ETM2 Part number 84874023
•Version ETM :
Controls temperature of machines using built-in PTC probes
Line break or probe short-circuit detection
•Version ETM2 / ETM22 :
Fault latching function
Pushbutton for local reset
Remote reset via external contact
Pushbutton test facility
2 LEDs to indicate relay and power supply status
Part numbers
Specifications
Type
Output
Supply voltage
84 874 023
ETM2
1 changeover
120 V AC
Supply voltage Un
230, 120 and 24 VAC 50 / 60 Hz
Galvanic isolation by transformer
24 VDC no galvanic isolation
Operating range
0.85 to 1.10 Un
Nominal power
3 VA
Maximal power
5 VA
Immunity from micro power cuts
10 ms
Delay on pick
-up
500 ms
Insulation coordination
Category III, degree of pollution 2 conforming to IEC/EN 60664
-
1 / VDE 0110 : 4 KV/2
Max. resistance of cold probes
1500
Ω
Trip threshold
3100
Ω
±
10 %
Reset threshold
1650
Ω
±
10 %
Short-circuit detection
0 - 10
Ω
Measurement voltage as per IEC/EN 60034
-11
≤2,5V
Repetition accuracy with constant parameters
±
0.5 %
Temperature drift
±
0.05 % / o
C
Voltage-dependent drift
-2 %
Output
AgNi 90/10
Breaking capacity
2000 VA / 80 W
Max. breaking current
8 A AC
Max. breaking voltage
440 V AC
Min. breaking current
100 mA
Maximum rate
360 operations / hour at full load
Mechanical life (operations)
5 x 106
Electrical life
AC12 : 2000 VA - 105 operations
AC15 : Cos
φ
=
0,3 - 6000 operations
DC13 : L/R = 300 ms
- 6000 operations
Reset time
≤500ms
Response time
≤500ms
Display on ETM2/ETM22
- power supply
green LED
Display on ETM2/ETM22
-
Relay
yellow LED
Class of protection (IEC EN/60529)
-
Term. block
IP 20
Protection class (IEC EN/60529)
-
Casing
IP 50
Housing material
Self-extinguishing
Weight (g)
145
Terminal capacity
2 x 1.5 mm
2 with ferrule
2 x 2.5 mm
2 without ferrule
Temperature limit operation (IEC 68.1.14)
(°C)
-
20→+60°C
Temperature limits stored (IEC 68.1.1/2)
(°C)
-
30→+70°C
Relative humidity (no condensation)
95 % (+2 % ; -3 %)
Principles
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
23/06/2014 www.crouzet.com
Operating principle
Control relay is used in combination with PTC thermistor probes (not supplied) for thermal protection of machines (motors, alternators, transformers, etc). The probes are placed at critical points on
the equipment to be protected (normally inserted into the stator windings of motors). The resistance of the PTC probe has a positive temperature coefficient. As soon as the nominal trip temperature
of the probe is exceeded, the resistance of the probe increases rapidly. Protection relay detects this and opens the power supply circuit of the protected equipment (eg motor) and the yellow fault
indicator LED lights up (version ETM2/ETM22).
Test button
The ETM2/ETM22 has a TEST button which can be used to simulate a thermal overload in order to test the service condition of the relay.
Tripping
The relay drops out as soon as the protected equipment is subjected to a thermal overload, short-circuit or break in the probe measuring circuit.
Early warning of tripping
If the equipment being protected has another PTC proble with a lower nominal trip temperature, a second ETM/ETM2/ETM22 relay can be used to give early warning of tripping and thus prevent
breaks in operation.
Control relay ETM/ETM2/ETM22 is automatically reset as soon as the temperature drops below the trip threshod (the yellow fault indicator LED goes out).
The relay is reset either using the RESET pushbutton on the front face or by opening the external contact S2 (remote reset), or by cutting the auxiliary power supply (terminals A1 - A2).
If the auxiliary power is cut for a period of time greater than the reset time (500 ms), the relay is reactivated if the proble detects a normal temperature when the power supply voltage is restored.
N
o
Legend
Unit power-up
Resistance between terminals T1 and T2
Output relay
Principles
N
o
Legend
Unit power-up
Latching contact
Resistance between terminals T1 and T2
Output relay
Principles
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
23/06/2014 www.crouzet.com
The relay is reset either using the RESET pushbutton on the front face or by opening the external contact S2 (remote reset), or by cutting the auxiliary power supply (terminals A1 - A2).
If the auxiliary power is cut for a period of time greater than the reset time (500 ms), the relay is reactivated if the proble detects a normal temperature when the power supply voltage is restored.
N
o
Legend
Resistance R (
Ω
)
Nominal temperature
Tripping (°C)
Dimensions (mm)
ETM / ETM2 / ETM22
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
23/06/2014 www.crouzet.com
Connections
ETM2
N
o
Legend
S2 : fault memory
A1 - A2 : supply voltage
11 - 12 - 14 : output relay
T1
-
T2 : external PTC probe
Y1 - Y2 : remote reset contact
Connections
ETM
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
23/06/2014 www.crouzet.com
Legend
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Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
23/06/2014 www.crouzet.com
