Emerson MPR15 Series - Manual (Page 23)

Operation 23
25A Switch Mode Rectifier  NT5C06B / C Installation and User Manual
Rectifier failure alarm (RFA)
The rectifier incorporates facilities for monitoring its operational state and
extends a global alarm upon detection of an internal failure or a no load
condition (see Note below). When the rectifier operates in parallel with
other rectifiers and its output voltage is adjusted lower, the RFA LED will
change to RED and an RFA alarm will be sent.
Note: Give an alarm at no load condition only for the following
releases or under.
NT5C06BB, BB-1, BB-3, BC Rel. 10
NT5C06CA, CA-1, CA-3, CA-5 ,CC Rel. 10
NT5C06CB, CB-1, CB-3, CD Rel. 12
NT5CO6CE-61(-46) Rel. 12
Fan failure alarm
A fan failure will activate the fan alarm and inhibit the operation of the
rectifier. An RFA will also be issued upon inhibition of the rectifier.
Internal high voltage shut down (HVSD)
The rectifier includes a high voltage monitor. Whenever the rectifier output
voltage exceeds a value adjustable from -52 to -59.5 V it shuts down
immediately, locks out, and transmits an RFA. This function is not
dependent on the output load condition.
Local ON/OFF control (DC and optional AC breakers)
Circuit breakers are used to turn the rectifier ON/OFF locally and
disengage it from the DC circuit. The local OFF control overrides the
remote control signals.
Inrush current limiting fuse (F1)
A 3/4 A, 250 V fuse is connected in line with the soft start circuitry to
protect the input circuitry against high inrush currents in case of an
internal failure. On the MPR15E modes NT5C06CB/CD/CE, failure
of this fuse during operation will disable the unit. See the
“Recommended Replacement Parts” section to order a replacement
fuse.