Albright SD150A and SD250A Switches

These switches combine the dual function of a manual disconnect and coil operated line contactor. The benefits of this design include compact size and reduced installation costs combined with an electrical capacity sufficient for most small and medium size electric vehicles.

Modes of Operation
The operation of the SD150A and SD250A switches is such that with the operating knob depressed i.e. in the "Off" position, no electrical functions can take place. However if the knob is in the "On" position, the option of energizing the coil and thus closing the main contacts becomes available. The coil energisation can be carried out either through the vehicle keyswitch or as a result of a signal from the vehicle electronic controller.

When the SD150A and SD250A switches are used as an emergency battery disconnecting switch, manually depressing the operating knob will override the energised coil such that the main contact and the auxiliary contact will open until such time as the knob is again moved to the "On" position.

Operating Coils
These are normally continuously rated, although intermittently rated versions are also available.

Auxiliary Contacts
An integral auxiliary contact is fitted to the SD150A and SD250A. This has one normally open contact which closes when the knob is put into the "on" position. The status of the auxiliary contact on the SD150A and SD250A switches is not affected by the energisation or de-energisation of the coil.

An additional double circuit normally open, normally closed changeover auxiliary contact can be fitted to the SD150A and SD250A switches. Note: The suffix "A" indicates the fitting of auxiliary contacts.