Electrical Connection - Tecfluid Series LT Instruction Manual

13.4

Electrical connection

For the electrical installation it is recommended to use multiple conductor cables, and not
single cables, in order to guarantee the cable gland will stay watertight. The connector has a
PG9 cable gland for cables with outer diameters between 5 mm and 7 mm. The numbering
of the terminals is the following:
Terminal 2 is the normally open contact when the float is below the limit switch.
Make sure that the contact rating is not exceeded. If high loads are to be switched, use an
auxiliary relay.
When using inductive loads, such as relays or solenoid valve coils, surge arresters should be
installed to protect the reed contacts.
With a DC supply, a diode should be connected as shown.
For an AC supply, a RC circuit can be used as shown, although a varistor (VDR) is better
and is easier to select the right value. The VDR should have a breakdown voltage greater
than 1.5 times the rms voltage. The standard varistor ratings specify the rms working
voltage for the varistor, for example a S05K25 varistor will be for 25 V
have a breakdown voltage of 39 V at 1 mA.
The electrical installation should provide a fuse or circuit breaker to protect the reed switch
from overloads.
In the female connector:
Terminal 1: Common
Terminal 2: NO (Normally open)
Terminal 3: NC (Normally closed)
Earth terminal: Earth
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working and will
rms