40 Functional description
4.2.9.HVSD ( high voltage shutdown )
HVSD ADJ ( high voltage shutdown adjust ) potentiometer
Use this potentiometer to set the internal threshold level at which the local high voltage shutdown condition should occur.
Remote HVSD
In addition to the local high voltage shutdown feature, the controller of the power plant controller can shut down any rectifier by sending a high voltage shutdown signal, ground ( BAT RTN ) pulse. The rectifier will shut down within 50 ms if it is supplying more than 10% of its full load rating.
As is the case for the internal high voltage shutdown condition, two HVSD events must occur within an interval of two minutes to lock out the rectifier permanently. An ac breaker reset or an HVSDR signal can be used to restart the rectifier.
Local and remote HVSD reset
The rectifier may be reset from an HVSD condition locally by :
•toggling the ac circuit breaker to OFF then to ON ( or the ac breaker in the distribution panel )
•sending a remote ground signal to the HVSDR input through the controller restart ( provided the 'TR' lead has not been activated )
4.2.10.TR ( temporary inhibition ) and sequential start
Sequential start
The TR input can be interfaced to an external sequential start circuit.
UM5C05C P0745680 Standard 6.00 October 2001 | Emerson Energy Systems |