Exchanging The Electronics Module - AEC SM720 Operation Instructions Manual

Alex Electronics Co.
Check the resistance in the
probe
Remove the electronics module. Check the resistance between
the two plug connections. There must not be a connection
anymore (high impedance). If there is still a connection, exchange
the instrument or return it for repair
6.3

Exchanging the electronics module

If the electronics module is defective, it can be replaced by the
user.
In Ex applications(Group 2) , only instruments and electronics
modules with appropriate Ex approval may be used.
The sensor serial number is necessary. The serial numbers are
stated on the type label of the instrument, inside the housing or on
the delivery note.
To change the electronics modules do the following:
1. Turn off the transmitter power supply
2. Unscrew the housing cover
3. Unscrew the terminals of the old module with a screwdriver
4. Pull the connection cables out of the terminals
5. Loosen the screws of the module and the earth with a
screwdriver.
6. Pull out the old electronics module.
7. Compare the new electronics module with the old one. The
type label of the electronics module must correspond to that
of the old electronics module.
8. Insert the electronics module carefully. Make sure that the
plug is in the correct position.
i
Information:
Make sure that the housing is not rotated during the electronics
exchange. Otherwise the plug may be in a different position later.
9. Screw in and tighten the screws of the module and the earth
terminal with a screwdriver
10. Insert the wire ends into the open terminals.
11. Check the hold of the wires in the terminals by gently pulling
on them
12. Mount the probe into the vessel. Make sure that the probe is
uncovered.
SM720 Capacitive Level Transmitter
14