Motor control
➜ ETM / ETM2 / ETM22 motor thermal protection
■ 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
Specifications
Type Output Supply voltage Code
ETM 1 N/O contact 24 V AC/DC 84 874 015
ETM2 1 changeover 24 V AC/DC
ETM22 2 changeovers 24 V AC 84 874 035
1 N/O contact 120 V AC 84 874 013
1 N/O contact 230 V AC 84 874 014
84 874 025
1 changeover 120 V AC 84 874 023
1 changeover 230 V AC 84 874 024
2 changeovers 120 V AC 84 874 033
2 changeovers 230 V AC 84 874 034
4
General characteristics
Power supply characterisitcs
Supply voltage Un 230, 120 and 24 VAC 50 / 60 Hz
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 664.1 / VDE 0110 : 4
Input circuit characteristics
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 34-11 ≤ 2.5 V
Repetition accuracy with constant parameters ± 0.05 % with constant parameters
Temperature drift
Voltage-dependent drift -2 %
Output characteristics
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 AC DC
Maximum rate 360 operations / hour at full load
Mechanical life (operations)
Electrical life
General characteristics
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 (529) - Term. block IP 20
Class of protection (IEC 529) - Casing IP 50
Material housing Self-extinguishing
Weight (g) 145
Terminal capacity
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) 93 % (+2 % ; -3 %)
To order, see page 6
Galvanic isolation by transformer
24 VDC no galvanic isolation
KV/2
± 0.05 % / oC
6
5 x 10
AC12 : 2000 VA - 105 operations
AC15 : Cos ϕ = 0.3 - 6000 operations
DC13 : L/R = 300 ms - 6000 operations
2 x 1.5 mm2 with ferrule
2 x 2.5 mm
2
without ferrule
148
For more information www.crouzet.com
Dimensions
ETM / ETM2 / ETM22
100
77
5
78,5
11 14 12
Y2 11
Y1
14 12 A2
22,5
4,2
89,7
99,3
23
2
57
Connections
ETM ETM2 ETM22
U
+
CTP DIN 44081
A1 T1 T2
ϑ
+
A2
-
A1 - A2 : Supply voltage
11 - 14 : Output relay
T1 - T2 : External PTC probe
ETM
11
R
14
U
+
A1 T1
A2
CTP DIN 44081
T2
ϑ
+
Y1 Y2
1
12
-
Fault memory
B
A1 - A2 : Supply voltage
11 - 12 -14 : Output relay
T1 - T2 : External PTC probe
Y1 - Y2 : Remote reset contact
A1
11
A2
R
14
A1 - A2 : Supply voltage
11 - 12 -14 : Low threshold output relay (R1)
21 - 22 -24 : High threshold output relay (R2)
T1 - T2 : External PTC probe
Y1 - Y2 : Remote reset contact
Y1 Y2
T1 T2
11
21
12 14 22 24
4
R
S
T
11
A1
R
12 14
S0
S1
r
Y1 A2Y2
c1
T2 T1
>
S2
h1 c1
N
C1 : Contactor
S1 : ON button
S0 : OFF button
S2 : Remote reset contact
h1 : Fault indicator
c1
M3
~
1 6
PTC
DIN 44081
For more information www.crouzet.com
149
Principles
1330
4000
550
250
R( )
20
-20
0
TNF-20
TNF
TNF+15
TNF-5
TNF+5
ϑ( C)
1
2
Reset WITHOUT fault latching (Y1 and Y2 not connected for ETM2/ETM22)
Operating principle
Control relay is used in combination with PTC thermistor probes (not supplied) for thermal
U
3100
1650
10
0
4
Unit power-up
B
Resistance between terminals T1 and T2
C
Output relay
D
PTC probe specification
According to standard DIN 44081 (or IEC 34-11)
1
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
3
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, shortcircuit 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).
4
Resistance R (Ω)
B
Nominal temperature Tripping (°C)
C
Reset WITH fault latching (only for ETM2/ETM22) (Y1 and Y2 connected)
The relay is reset either using the RESET pushbutton on the front face or by opening the external
1
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.
2
Unit power-up
B
Latching contact
C
3
Resistance between terminals T1 and T2
D
Output relay
E
B.P.
"reset"
3100
1650
10
U
S2
0
4
150
For more information www.crouzet.com
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