Follow @kepco_careers
Advanced Search
Kepco Power Solutions
718-461-7000
HSP power supplies provide both visual and electrical indication of the status of various critical functions including source power status, output status, fan status and overtemperature condition; both visual and signal indicators are provided.

Visual indication is provided via the four LED indicators located on the front panel. Signal indication is obtained via four sets of Form C dry relay contacts accessed via the I/O connector; all three contacts are provided to the user, permitting the selection of either normally-open (NO), normally-closed (NC) or both for any application.

The definition of "normal" in this instance refers to the status of the contacts when the HSP is powered and operating normally (no fault); status flag outputs remain valid even when source power is removed. These relay contacts are SELV and are isolated from each other and from the output by 100V d-c to permit flexibility in application. A description of the function of each status signal follows. The Table below indicates the condition of status flags and indicators for normal, fault, and no power conditions.

STATUS INDICATORS AND FLAGS

Condition Signal/Indicator Status
Normal (1) Fault Detected No Power
Applied
Source
Power
Status
POWER indicator ON (Green) OFF ON
Source power status NC Closed (2) Open (2) Open (2)
Source power status NO Open (2) Closed (2) Closed (2)
Output
Status
DC FAIL indicator OFF ON (Red) OFF
Output status NC Closed (2) Open (2) Open (2)
Output status NO Open (2) Closed (2) Closed (2)
Fan
Status (3)
FANFAIL indicator OFF ON (Red) OFF
Fan status NC Closed (2) Open (2) Closed (2)
Fan status NO Open (2) Closed (2) Open (2)
Overtemperature
Status (3)
OVERTEMP indicator OFF ON (Amber) OFF
OVERTEMP status NC Closed (2) Open (2) Closed (2)
OVERTEMP status NO Open (2) Closed (2) Open (2)
(1) Normal is defined as the HSP powered and operating with no faults (source power within specifications, output power within rated limits, fan operating, and no overtemperature condition sensed.
(2) Closed and Open are referenced to the associated status common termination.
(3) Upon initial turn-on, fan and overtemperature status lines will be in a "Normal" condition unless a fault condition is sensed.

Power Indicator/Source Power Status Flags

Monitors available source voltage to determine if sufficient energy is available to sustain rated output for normal operation. These signals indicate a fault condition until the bulk voltage is greater than 390V d-c. Once the bulk voltage reaches 390V d-c (indicating that the PFC boost converter is operating and assuring that full ride-through time is available at rated load) these signals revert to  normal  (see Table). These signals will indicate a fault a minimum of 5 milliseconds prior to loss of output regulation due to source power loss, providing a transparent source power ride-through time of 21.5 milliseconds; POWER STATUS is not reset until the bulk d-c again reaches 390V d-c; see Figure below for timing relationships.

HSP Power Supply Timing Relationships

Timing Relationships

DCFAIL Indicator and Output Status Flags

The OUTPUT status flags and DCFAIL indicator LED are both controlled by the output fault detector circuit, which monitors both output voltage and module current to assess d-c output status. An output fault condition (DCFAIL indicator "ON") is generated if one of three fault conditions is detected: (1) Overvoltage fault or (2) Undervoltage Fault - output voltage is outside specified regulation limits, or (3) Undercurrent fault - the power supply module is supplying less than 70% of the current required by the circuit (as indicated by the load sharing signal) while the output voltage is within specification limits.

A fault condition is not generated for a combination of overvoltage and undercurrent indications, as these are mutually exclusive conditions for power supplies which are not part of a parallel-redundant configuration; this combination does, however, indicate proper operation for operational power supply modules which are part of a parallel-redundant power scheme in which one or more power supply modules are presenting overvoltage failures.

The Fault Detector Operation Table (below) provides an operating matrix of the DCFAIL status function; see timing relationships. The output voltage fault limits are 5% of programmed output voltage, while the undercurrent fault limit is < 70% of required module current; signal reset requires output voltage recovery to within the specified 1% regulation range and/or module current recovery to > 85% of required module current, respectively.

UNDERVOLTAGE UNDERCURRENT OVERVOLTAGE DC FAIL STATUS
N N N OFF
Y X * ON
N Y N ON
* N Y ON
* Y Y OFF
Y = YES,   N = NO,   X = DON′T CARE,   * = EXCLUDED BY ANOTHER ASSUMED CONDITION

OVERTEMP Indicator and Status Flags

This fault is generated in the event that either the input or output module heatsink temperature rises above a safe operating level; output regulator shutdown occurs simultaneously. Recovery occurs automatically upon reduction of internal temperatures to normal levels.

FANFAIL Indicator and Status Flags

This fault is generated in the event of a failure of the internal cooling fan; a delay of approximately 5 seconds is incorporated to prevent nuisance indications at turn-on. Reset occurs when fan operation resumes.

PREVIOUS TOP NEXT

ProductsSupportLiteratureContact UsCareersAbout

KEPCO, INC. • 131-38 SANFORD AVENUE • FLUSHING, NY. 11355 U.S.A.
TEL (718) 461-7000 • FAX (718) 767-1102
www.kepcopower.com • email: hq@kepcopower.com