Grundfos ALR 20/A Ex Instrucciones De Instalación Y Funcionamiento página 9

4. Starting up the product
Startup must be carried out by authorised
persons only.
Switch on the power supply and check that the signal
is as expected, 5 mA for 0 % water. If the signal is
ok, the system is ready for operation.
5. Operating the product
For operation, supply the indicated voltage to the
ALR 20/A Ex relay. To integrate the ALR 20/A Ex
relay into the motor control, use the switching
contacts (1, 3, 4). During normal operation the intern
relay turns on and off and controls the pins 1, 3 and
4.
In case of a fault, if water is detected in the oil, cable
break of the switch, short circuit of the cable or
power failure, the relay is activated and controls the
pins 1, 3 and 4.
A device fault is indicated by an illuminating diode on
the front panel of the ALR 20/A Ex, see fig. 3, pos. 4.
It is possible to draw an external fault signal over
pins 1 and 3 (closed in case of fault).
As soon as the reason for the fault is eliminated, the
product restarts automatically and returns to normal
operation. Non-automatic restart of the motor must
be made by settings in the control.
6. Storing the product
Moisture inside the packaging can damage
the electrical connections.
Store the product in the original packaging to protect
the product against moisture and heat.
Storage temperature: -20 to +40 °C.
After long periods of storage, carry out a visual
inspection of the product to make sure there is no
moisture inside the packaging.
7. Product introduction
7.1 Product description
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1
2
3
Fig. 3 ALR 20/A Ex relay
Pos. Designation
1 ALR 20/A Ex housing
2 Adjusting screw (Switch point)
3 Leakage sensor connections
4 Indicator light (Error indicator)
5 Power supply connections (L, N)
6 Relay connections
7.2 Applications
The leakage sensor relay ALR 20/A Ex functions
together with the leakage sensor AL05 Ex as a
leakage detection system for a submerged mixer,
flowmaker or recirculation pump.
The ALR 20/A Ex is installed outside of the wet area,
the leakage sensor AL05 Ex is installed in a
submerged mixer, flowmaker or recirculation pump,
and wired to the ALR 20/A Ex.
In case of defective sealing, the penetrating water is
detected by the sensor and further damages can be
avoided.
7.3 Intended use
The ALR 20/A Ex is used together with the leakage
sensor AL05 Ex to monitor the sealing of a
submerged mixer, flowmaker or recirculation pump.
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4
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