Grundfos APG Serie Manual De Usuario página 9

7.1.1 Temperature sensors (in stator windings)
All pumps have integrated temperature sensors in
the stator windings. Via the safety circuit, the
temperature sensors will cut out the motor in case of
overtemperature, approx. 150 °C. The maximum
operating current of the temperature sensors is 0.5 A
at 500 VAC and cos φ 0.6.
Non-explosion-proof pumps only have one set of
temperature sensors.
Explosion-proof pumps have two sets of temperature
sensors. The extra set of sensors will open at a
temperature that is approx. 10 °C higher than the
opening temperature of standard sensors. The extra
set of sensors provides additional protection against
overtemperature in potentially explosive
environments.
The temperature sensors must be connected to the
safety circuit of the motor-protective circuit breaker
via the temperature relay (No 98123042). See fig. 3.
Figure 2 shows the electrical connection of a three-
phase, explosion-proof APG pump.
The temperature sensors are connected to the
monitoring cable and must be connected to the
separate thermistor relay fitted in the safety circuit of
the pump controller.
The temperature sensors of pumps above 1.6 kW
and three-phase motors are connected to the power
supply cable. To ensure automatic restart of the
motor when cooled (to ambient temperature), the
leads marked T1 and T3 must be connected to the
safety circuit. For explosion-proof versions, the same
applies to the leads marked T1 and T2.
Warning
Separate motor-protective circuit breakers/
control boxes must not be installed in
potentially explosive environments.
PE U U V V
1 2 1
+10°C 140°C
Fig. 2 Wiring diagram, sensors
W W T T T S S
2 1 2 1 2 3 1 2
Temperature relay
EMT6-DB AUTO
L +
A1
Power
U
S
A2
PTC
N
A1/A2
T1/T2
13-14, 21-22
Tripped LED
Fig. 3 Wiring diagram, temperature relay
21 13
Tripped
T1 T2/T3 22 14
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