Tecfluid LT-APR - Manual (Page 3)

3
OPERATION
The LT-APR series are limit switches based on a bi-stable SPDT reed.
The reed is activated by the magnetic field from the float of a level indicator of the LT series.
TECHNICAL DATA
• Connector with PG7 cable gland. Soldered connections.
• Polyamide housing with IP65 ingress protection.
• Maximum working current: 0.5 A.
• Maximum working voltage: 250 VAC.
• Maximum power: 60 VA.
• Temperature range: -10, +70ºC
• Conforms with the Directive 73/23/EEC
CONNECTION
3 1
2
Terminal 2 is the normally open contact when the float is below the level switch.
For the electrical installation it is recommended to use multiple conductor cables to guarantee the
instrument will stay water tight.
The connector admits cable diameters from of 4.5 to 7 mm.
The electrical installation should provide a fuse or circuit breaker to protect the reed switch from
overloads.
When installing the connector, make sure that the cable gland closes over the cable and that the
connector with the rubber seal is well screwed down to maintain the IP65 rating.
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 electro-valve coils, surge arresters should be installed
to protect the reed contacts.
With a DC supply, a diode should be connected as shown.
In the female connector (A): (see the following page)
Terminal 1: Common
Terminal 2: NO
Terminal 3: NC
Earth terminal: No connection