Tecfluid Series LT Instruction Manual

Tecfluid Series LT Instruction Manual Manual pdf 28 page image

2813.4 Electrical connectionFor the electrical installation it is recommended to use multiple conductor cables, and notsingle cables, in order to guarantee the cable gland will stay watertight. The connector has aPG9 cable gland for cables with outer diameters between 5 mm and 7 mm. The numberingof 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 anauxiliary relay.When using inductive loads, such as relays or solenoid valve coils, surge arresters should beinstalled 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 betterand is easier to select the right value. The VDR should have a breakdown voltage greaterthan 1.5 times the rms voltage. The standard varistor ratings specify the rms workingvoltage for the varistor, for example a S05K25 varistor will be for 25 V rms working and willhave a breakdown voltage of 39 V at 1 mA.In the female connector:Terminal 1: CommonTerminal 2: NO (Normally open)Terminal 3: NC (Normally closed)Earth terminal: EarthThe electrical installation should provide a fuse or circuit breaker to protect the reed switchfrom overloads.