KEPCO RA 19-8B User Manual

QUICK START GUIDE

KEPCO

An ISO 9001 Company.

RA 19-6B, RA 19-7B, RA 19-8B

RACK ADAPTER

I — INTRODUCTION

SCOPE OF MANUAL. This Quick Start Guide covers

installation and operation of Kepco RA 19-(X)B Rack
Adapters (i.e., RA19-6B, RA 19-7B and RA 19-8B) for two
common configurations: independent operation and paral­lel operation. For the full capabilities and specifications of
the RA 19-(X)B, and to take advantage of the many choices
and features not covered in this Quick Start Guide, the user
is urged to download the complete Operator’s Manual from
the Kepco web site at www.kepcopower.com/support/
opmanls.htm#ra19-xb

DESCRIPTION. Kepco RA 19-(X)B rack adapters (Fig­ure 1) are specifically designed for any combination of
Kepco’s 3U 50W, 100W or 150W HSF and HSF-PFC
power supplies. RA 19-6B holds up to six 150W HSF 3U
power supplies; RA 19-7B holds up to four 50W or 100W
(slots 1 through 4) and up to three 150W HSF power sup­plies (slots 5, 6 and 7); RA 19-8B holds up to eight 50W or

RA 19-(X)B

Rack Adapter

100W HSF power supplies. Optional cover plates are avail­able to cover unoccupied slots

These rack adapters are user-configurable for parallel,
series, or independent power supply operation. Forced cur­rent sharing and OR’ing diodes for N+1 redundancy are
built into the HSF power supplies. A-C inputs are split to
deliver independent source power to left and right power
supply groups. User-configurable keying can ensure that
only the correct power supply can be installed in a keyed
slot. Input/output connections between RA 19-(X)B and
HSF power supply are via HSF connectors that plug into
corresponding connectors of the RA 19-(X)B. All connec­tions are made at the rear panel (see Figure 2).

FIGURE 1. RA 19-(X) B RACK ADAPTERS, FULLY POPULATED

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©2009, KEPCO, INC 1
Data subject to change without notice 228-1681

FIGURE 2. REAR PANEL CONNECTIONS, TYPICAL

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II — PRE-INSTALLATION.

NOTE: Either local or remote sensing MUST

be used. For independent operation
configure the DIP switches. For paral­lel operation use external wires

DIP SWITCHES. Each slot has one DIP switch (see
Figure 3): DIP 1 is for PS1 sense lines; DIP 2 is for PS2
sense lines and for paralleling PS1 and PS2. The rest of
the DIP switches are similar to DIP 2, each configuring the
sense lines for that slot and for paralleling the adjacent
(lower number) slot. Table 1 describes the function of each
DIP switch position. See below to access the DIP switches.

ACCESSING DIP SWITCHES. The DIP switches
(Figure 3) are accessible either a) from the front without
disassembly by using a long flat-tip screwdriver after
removing all power supplies from the rack, or b) by sepa­rating the rear panel from the chassis as described below:

1. Remove all power supplies from the rack adapter.

2. Remove eight hex spacers securing the four I/O connec­tors to the rear panel.

the rear panel from the chassis. It is not necessary to
remove the ground connection (if present) between the
rear panel and the chassis.

4. Remove seven screws (three at the top and four at the
bottom) securing the back plate to the chassis and
remove the rear panel to gain access to the interior com­ponents.

OPTIONAL KEYING: HSF power supplies are keyed
by voltage at the factory. A keyway can be established at
the rack adapter by installing a key pin (supplied) into the
corresponding hole as indicated in Figure 3 so that the pins
match the open holes of the power supply. Secure with
mounting nut at the rear panel using two 1/4-inch nutdriv­ers or deep sockets. DO NOT ALTER THE KEYING ON
THE POWER SUPPLY.

INDEPENDENT OPERATION. The RA 19-(X)B rack
adapter is shipped with the DIP switches of all slots config­ured for independent operation (see Figure 3) and local
sensing. Refer to RA 19-(X)B manual for remote sensing.

3. Remove four screws (two at the top and two at the bot­tom) securing the rear panel to the chassis and separate

TABLE 1. REAR PANEL (INTERIOR) DIP SWITCH FUNCTIONS

DIP

SWITCH

POSITION

1, 2

3, 4

(SEE

NOTE)

5

6, 7

8

FUNCTION DIP SWITCH SETTINGS

Position 1 connects +V+ to +S, Position 2 connects –V to –S.

Local /
Remote
Sensing

Selection

Connect

Sense
+ and –

in parallel

Current

Balance

(forced

current

share)

Close on

Failure

Alarm

Open on

Failure

Alarm

Both required ON (factory default) for independent operation with Local Sensing.
Both required OFF for:

a) Independent configurations using Remote Sensing.
b) Independent configurations using Local Sensing with user supplied connections from +V+ to +S and –V to –S.
c) All parallel configurations (sensing must be established using external wires).
d) All series connections.

Position 3 connects +S to adjacent slot +S, Position 4 connects –S to adjacent slot –S.
Both required OFF (factory default) for all configurations except parallel configurations using DIP switch settings to con­nect the sense leads in parallel.
Both required ON for parallel configurations using DIP switch settings to connect the sense leads in parallel.

Required ON for parallel operation with forced current share (connects current share lines in parallel) unless connec­tions are made via external wires
Required OFF (factory default) for

a) independent and series configurations.
b) Parallel configurations using external wires at I/O connector to connect CSB (current share bus) lines in parallel.
c) Parallel configurations without forced current sharing (current balancing),

When set to OFF (factory default), individual power supplies produce closure between I/O connector N.O. and COM
pins upon failure.
When set to ON, parallels N.O pins of adjacent slots to allow a single alarm to provide failure indication (contact closure
between N.O. pin and COM pin) if any one of many power supplies fails.

When set to OFF (factory default), individual power supplies produce open between I/O connector N.C. and COM pins
upon failure.
When set to ON, connects N.C to COM between adjacent slots so that individual alarms are connected in series. This
allows a single alarm to provide failure indication (contact open between N.C. pin and COM pin) if any one of many
power supplies fails.

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FIGURE 3. BACKPLATE, INTERIOR VIEW, DIP SWITCHES AND KEYING

PARALLEL OPERATION. The most common use for
the RA 19-(X)B rack adapter is with two or more HSF’s
connected in parallel to a single load with forced current
sharing to increase current output, increase reliability and/
or provide redundancy. Only adjacent slots can be con­nected in parallel using DIP switches.

4. Set position 6 and 7, to OFF. This isolates the ALARM
(N.O.) and ALARM (COM) lines between slots 4 and 3.

5. Set position 8 to OFF. This position is only set to ON for
open-on-fail alarm circuits.

Configure DIP 3:

Figure 4 shows HSF’s in slots 2 and 3 connected in paral­lel (master/slave, master established automatically by
voltage) with forced current sharing and a close-on-fail
alarm circuit. Both HSF modules are configured for output
voltage to be adjusted from the front panel trimpot (factory
default setting). See HSF operator manual for other output
voltage adjustment options.

Configure DIP 4:

1. Set positions 1 and 2, to ON. This connects +S to +V
and –S to –V for slot 4, establishing local sensing for
slot 4 if slot 4 is to be used.

2. Set positions 3 and 4, to OFF. This isolates sense lines
(±S) between slots 4 and 3.

3. Set position 5 to OFF. This isolates the current share
bus (CB) between slots 4 and 3.

6. Set positions 1 and 2, to ON. This connects +S to +V
and –S to –V for slot 3, establishing local sensing for
slot 3.

7. Set positions 3 and 4, to ON. This connects sense lines
(+S to +S and –S to –S) for slots 3 and 2.

8. Set position 5, to ON. This connects the current share
bus (CB) for slots 3 and 2.

9. Set positions 6 and 7 to ON. Position 6 connects the
normally open ALARM (N.O.) lines and position 7 con­nects the ALARM (COM) (common) for slots 3 and 2,
implementing a close-on-fail alarm circuit (see equiva­lent schematic shown in Figure 4. If either PS2 or PS3
fails, a contact closure provides continuity across pins 7
and 14 of both I/O 4 and I/O 3.

10.Set position 8 to OFF. This position is only set to ON
for open-on-fail alarm circuits.

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Configure DIP 2:

1. Set positions 1 and 2, to ON. This connects +S to +V
and –S to –V for slot 2, establishing local sensing for slot

2.

5. Set position 8 to OFF. This position is only set to ON for
open-on-fail alarm circuits.

SERIES OPERATION. See RA 19-(X)B Operator
Manual for series operation details.

2. Set positions 3 and 4, to OFF. This isolates sense lines
(±S) between slots 2 and 1.

3. Set position 5 to OFF. This isolates the current share
bus (CB) between slots 2 and 1.

4. Set position 6 and 7, to OFF. This isolates the ALARM
(N.O.) and ALARM (COM) lines between slots 2 and 1.

ALARMS. For independent configurations, Close on Fail
contact closure is across I/O connector pins for ALARM
N.O. and ALARM COM (see Figure 4). Open on Fail cir­cuits are across I/O connector pins for ALARM N.C. and
ALARM COM. Figure 4 shows a parallel close-on-fail circuit
for slots 2 and 3 using the DIP switches to make the con­nections. See Operator Manual for other options.

FIGURE 4. SLOTS 2 AND 3 CONFIGURED FOR PARALLEL OPERATION, WITH CLOSE ON FAIL ALARM CIRCUIT

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III — INSTALLATION

MOUNTING RACK ADAPTER: The rack adapter

mounts directly to EIA-RS 310D standard 19" racks via
the two mounting ears; two screws are required per
mounting ear for proper support.

CAUTION: Rack adapter should be mounted before
installing power supplies.

Two 8-32 threaded holes (see Figure 2 are provided adja­cent to each input power terminal block which can be
used for user-supplied strain relief cable clamps if desired.

IV — WIRING

A-C WIRING: It is the user’s responsibility to obey all

local, national and international safety rules regarding
field-wired apparatus and the grounding of the metal
cover and case of any instrument connected to the a-c
power source. Grounding is an intrinsic part of the safety
aspect of the unit.

SOURCE POWER: Source power requirements are
determined by the HSF power supply (see HSF power
supply Instruction Manual); no adjustment or modification
of the rack adapter is required.

Source power can also be custom configured via jumpers
on the internal PC board. Contact Kepco Applications
Engineering for further details.

Wire must be sized according to expected current. Wire
size range for each terminal block is AWG 20-10; torque
to 6 lb-in (0.6 N•M) maximum. CAUTION: PROTECTION

OF INPUT WIRING REQUIRES USER-CONFIGURED
SAFETY INTERRUPTS. The terminals are labeled L, N,

and G. Their functions are:

• Terminal G (Ground) is the safety ground con­nection for the RA 19-(X)B.

INSTALLATION/REMOVAL OF HSF POWER
SUPPLIES: To install each HSF power supply insert

HSF power supply in selected slot until power supply
front panel is flush with rack adapter chassis. and secure
with two front panel screws on power supply.

CAUTION: Do not overtighten these screws: max.
torque is 2 in.-lbs (0.23 N x m).

WARNING: Removal of HSF power supply from a
“live” system must be done only by authorized ser­vice personnel after HSF power switch is set to OFF.
Dangerous voltages may be accessible through the
open slot after a power supply is removed.

• Terminals L (Line Phase) and N (Neutral) are
connected to the input power entry connectors.
Source power is distributed to the power supplies
according to the label on the rear panel.

CONTROL SIGNALS: Access to all the control sig­nals for each HSF power supply is provided via two 15-pin
D-subminiature I/O connectors on the rear panel of the
rack adapter (see Figure 2). Four mating connectors
(Kepco P/N 142-0449) are provided in a plastic bag.

OUTPUT LOAD: Load connections to the rack adapt­ers are achieved via two 4-terminal terminal blocks
located on the rear panel assembly. DC OUTPUT + and –
for PS1 and PS2 are on one terminal block and + and –
for PS3 and PS4 are on the other. Wire must be sized
according to expected current. Wire gage may be
between 20 GA and 10 GA; torque to 6 lb-in (0.6 N•M)
maximum. As the length of load wires increases, ripple
and noise may increase proportionally, therefore length
and placement are critical for minimum ripple and noise. A
filter consisting of a 50mF electrolytic capacitor in parallel
with a 0.01mF capacitor must be used to eliminate
unwanted ripple and noise pickup on the load wire during
measurements. For remote sensing refer to RA 19-(X)B
Operator manual. For noise-sensitive applications the
load wires and sense wires must be twisted and/or
shielded.

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