While the two terms sound similar and do perform similar functions they are distinct.

• GIS Reset is used to clear an interlock has been tripped and the safety function completed successfully.

• GIS Fault Reset is required when an interlock has been tripped and the safety fails to compete successfully.

GIS Reset

GIS reset is used when an interlock has been tripped and the safety function completes successfully. Some safety functions require that a trip be latched to prevent restarting. A GIS reset can be accomplished by pressing the hardware pushbutton on either of the HMI (utility level or control room).

GIS Fault Reset

GIS fault reset is required when an interlock has been tripped but the associated safety function fails to achieve the designated safe state. i.e. there has been a failure with GIS. A GIS reset will not clear a GIS fault.

This is associated with the Light Path logic. If one of the redundant means or blocking the light path fails to close properly a GIS fault is latched.

Safety Shutter Timeout Fault

The safety shutter has failed to close within 3.0 seconds of being activated.

M1 Cover Timeout Fault

The M1 Cover has failed to close within 20 seconds of being activated.

Aperture Cover Timeout Fault

The Aperture Cover has failed to close within 135 seconds of being activated.

Other Resets in the GIS

The three Kuebler Encoders also feature local reset buttons. Follow this procedure: Kuebler Safety Encoder Reset .

Mount Azimuth Kuebler Fault

If the Mount Azimuth Kuebler gets into a faulted state it can be reset remotely by using the appropriate button on the GIS HMI. This button should not be pressed unless there is an existing fault as it might generate a fault.

Mount Altitude Kuebler Fault

If the Mount Altitude Kuebler gets into a faulted state it can be reset remotely by using the appropriate button on the GIS HMI. This button should not be pressed unless there is an existing fault as it might generate a fault.

Coude Azimuth Kuebler Fault

If the Coude Azimuth Kuebler gets into a faulted state it cannot currently be reset remotely by using the corresponding button on the GIS HMI. This button should not be pressed as it might generate a fault. This fault currently has to be reset but using the local button on the Kuebler.