The PROTECTION message appears because the interlock protection circuit is activated.
TOS5300 series has an interlock function that can be released by connecting the specified pins on the SIGNAL I/O connector on the rear panel.
The SIGNAL I/O plug supplied with TOS5300 can temporarily release the interlock.
We recommend using the interlock with a door switch to prevent contact with high voltage parts during testing.
For more details, read the user’s manual – chapter of Turning the Power On – Checking indicators and the state of the interlock feature.
