TF42-B are economical, electromechanical motor protection devices for currents up to 38A in railway applications. The devices meet the current railway standards and are therefore suitable for installation in passenger areas and driver's cabs of trains that frequently travel in tunnels and underground. In the event of overload, they offer reliable thermal protection for the connected motors. TF42-B are normally attached to contactors AF09 to AF38, but with the help of a single installation set, the devices can also be mounted separately on a DIN rail. If the motor current set on the current scale is exceeded, the relays trigger via bimetallic elements and thus change the switching position of the two auxiliary contacts 1S/1Ö. This switches off an upstream contactor. The relays allow manual or automatic resetting, they have a test and stop function and a triggered display. The current scale of the devices can be sealed. Accessories such as reset buttons and wire reset switches complete the range. TF42-B have tripping class 10, are temperature compensated and sensitive to phase failure. They meet the international railway standards IEC 60077 in the applicable parts, IEC 61373 (category 1, class B) for shock and vibration as well as the European safety standard EN 45545-2 for fire and smoke.
| Property | Value |
| Connection type main circuit: | Screw connection |
| Opener: | 1 |
| Maker: | 1 |
| Changer: | 1 |
| Adjustable current range: | 1.7 to 2.3 A |
| Mounting type: | Direct mounting |
| Trip class: | CLASS 10 |
| Max. Rated operating voltage Ue: | 690 V |
| Reset function input: | no |
| Reset function automatic: | yes |
| Reset function button: | yes |
