14
HSF (M) 300W 042315
FIGURE 12. ±PF POWER FAILURE OPTOCOUPLER TIMING DIAGRAM
3.9
LOCAL/REMOTE SENSING
HSF (M and MZ) 300W Power Supplies allow remote error sensing which can compensate up to
0.4 Volts per load wire. Local/Remote error sensing is configured by means of separate DIP
switches mounted on the RA 19-4C Rack Adapter (see RA 19-4C Rack Adapter Operator Man-
ual). Either local or remote sensing MUST be used, otherwise the units will not operate.
3.10
RETAINING LATCHES
HSF power supplies are provided with (2) retention latches located at each side of the bottom
edge of the front panel (see Figure 5). These latches work in conjunction with the RA 19-4C rack
adapters to prevent unauthorized or inadvertent module extraction from an operating power sys-
tem. The latch is engaged by loosening the cap-head screw approximately 1/2 turn CCW (use 5/
32" hex key) and sliding the latch down to the bottom of the slot, then retightening the cap-head
screw CW until snug. DO NOT OVERTIGHTEN! To release, follow the same procedure, except lift
the latch to the top of the slot. Be sure to move the latch completely up or down to ensure full
engagement and disengagement of the latching mechanism. When the HSF power supply is not
installed in its plug-in rack adapter, it is recommended that the latch be secured in the open (up)
position to prevent damage.
NOTE: Retaining latches must
not
be used to secure the HSF power supply in the rack
adapter for shipping purposes.
4.
LOAD CONNECTION
Connect the load to (+) and (–) terminals at the rear panel of the Rack Adapter (see RA 19-4C
Instruction Manual for details).
5.
CONNECTING MULTIPLE POWER SUPPLIES
All connections to multiple HSF power supplies must be made via the I/O mating connectors at
rear of the Rack Adapter or by the Rack Adapter DIP switches. These connections, including the
configuration of the two internal HSF DIP switches, are described in the Rack Adapter Instruction
manual, and include:
•
Using one power supply to control the output of multiple supplies.
•
Using parallel master/slave configurations (for increased current or redundancy) where
the user either predetermines the master or allows the load to determine which is the
master. These configurations also cover the use of the Current Balancing feature of the
HSF power supply.
•
Using series configurations (for increased voltage).
•
Using open-on-fail or close-on-fail alarm schemes with multiple power supplies.
