KEPCO RA 19-1U Operator Manual - Manual (Page 33)

RA 19-1U 020413
2-17
2.4.4 ALARM CONFIGURATIONS
The 1U HSF Power Supplies each provide a normally closed (N.C.) and normally open (N.O.)
line referenced to common (COM) for use as an alarm at the users discretion. The N.C. line
opens upon failure, the N.O. line closes upon failure.
NOTE: HSF-1URX and -1URY models do not include the normally open (N.O.) line, so
close on failure configurations are not applicable.
The RA 19-1U is configured at the factory for independent operation of these lines. It is possible
to configure these alarm lines to allow multiple power supplies to provide a failure indication
using the N.O. (close on failure) lines, N.C (open on failure) lines, or both. Each alarm circuit
can be configured in two ways: either by rear panel DIP switches or by external wiring of the I/O
mating connector. Use external wiring of the I/O mating connector if DIP switch specifications
noted in the following CAUTION will be exceeded.
CAUTION: The user is responsible for ensuring that the alarm circuit does not exceed
the HSF alarm relay switching specifications: 1A @ 30V d-c or 0.5A @ 125V
a-c. If the alarm circuit is configured using the rear panel DIP switches, the
user is responsible for ensuring that the alarm circuit does not exceed DIP
switch specifications: 100mA, 50V d-c, maximum.
CAUTION: For HSF-1URX and -1URY models there is no isolation between ±RC, d-c out-
put and alarm circuit. For HSF-1URC and -1URY models there is no isolation
between ±IMON, d-c output and alarm circuit.
2.4.4.1 N.O. ALARM LINE (CLOSE ON FAILURE)
The N.O. and COM line of each 1U HSF supply provide a closed contact (short circuit) upon fail-
ure. To configure multiple power supplies so that a failure of any supply produces a failure indi-
cation, it is necessary to connect the N.O. lines in parallel and the COM lines in parallel.
2.4.4.1.1 CLOSE ON FAILURE USING REAR PANEL DIP SWITCHES
Close on failure for multiple power supplies can be accomplished by setting DIP switch positions
6 and 7 to ON (closed). associated with each adjacent slot included in the alarm circuit. For
example, for PS1 and PS2, set DIP switch 2, positions 6 and 7 to ON (closed). The failure indi-
cation (short circuit) will be present across both N.O.1 and COM1, and N.O.2 and COM2. Figure
2-12 is a simplified diagram illustrating a close on failure alarm configuration for four power sup-
plies using rear panel DIP switches.