Motor protection based on PTC sensors is one of the most effective and reliable protective measures against thermal overload in electrical machines. The protection unit is composed of the INT69 motor protector and the PTC sensors. Due to its compact construction, the INT69 is suitable for installation in electrical devices or in the terminal boxes of electrical machines.
Functional description
If the temperature in one of the monitored parts or sections reaches the nominal response temperature of the respective PTC sensor, the sensor becomes highly resistive and the motor protector switches off. The device switches itself on again after cooling back down.
The relay's switching output is a potential-free changeover contact. This circuit works in accordance with the closed-circuit principle, i.e. even in the event of a sensor or cable break, the relay returns to its rest position and switches off.
The sensor, relay and supply current circuits are galvanically isolated from each other.
KRIWAN INT69. : | PARTS NO. 22A460 / 22A461 |
Mounting | Electrical mashines |
Supply voltage | AC 115-230V |
Permitted ambient temperature | -30…+70°C |
Temperature measuring circuits: Type | 1-9 PTC sensors |
Temperature measuring circuits: R_25, total | <1.8kΩ |
Temperature measuring circuits: R_trip | 4.5kΩ ±20% |
Temperature measuring circuits: R_trip, static | 4.5kΩ ±20% |
Temperature measuring circuits: R_reset | 2.75kΩ ±20% |
Temperature measuring circuits: Max. length connection line |
30m |
Relay: Connection | AC 240V 2,5A C300 AC/DC 24V 20mA |
AC 240V 2.5A C300 AC/DC 100mV 0.5mA | |
Relay: Mechanical service life | Approx. 1 million switching cycles |
Protection class acc. To EN 60529 | IP20 |
Connection type | Screw type terminal |
Housing material | PA glas-fibre-reinforced |
Mounting | Screw mounted |
Dimensions | Refer to dimensions in mm |
Weight | Approx. 100g |