Parallel Operation; Figure 8 - Connection Diagram For Parallel Operation - Unipower Bluestrak Series Operating Manual

P O W E R I N G T E C H N O L O G Y
13.0

PARALLEL OPERATION

13.1 Parallel Connection - Two or more BLUEstreak modules can be operated in parallel by
connecting their outputs in parallel and connecting their current sense terminals together
(pin D2). The BLUEstreak 19-inch rack power shelves permit conveniently operating two,
three or four units in parallel in either redundant mode or non-redundant mode.
13.2 Redundant Operation - Connecting two BLUEstreak modules in parallel, with or without
the compatible 19-inch rack, so that the full output load current can be carried by one unit
results in 1+1 redundant operation. While operating normally, the load current is shared
approximately equally between the two units. Should one BLUEstreak module fail, the full
load is then maintained by the other unit. The failed unit can then be replaced (hot-swap)
without affecting the load current. This operation is facilitated by an active ORing circuit
built into the module. 1+1 redundancy with quick replacement of a failed unit results in
virtually infinite MTBF. 2+1 or 3+1 redundancy works the same way except that the full
load is carried by two out of three or three out of four units respectively.
Non-Redundant Operation - Higher output load currents can be realized by operating
13.3
two or three or four modules in the non-redundant mode to achieve up to 4000 watts for
two modules, 6000 watts for three modules or 8000 watts for four modules. The units are
connected in parallel the same as before. In this case if one unit fails, the load will lose
power since only part of the load current can now be supplied by the remaining module(s),
which will go into current limit. The failed unit can be quickly replaced, however, without
turning the power off (hot-swap) to restore load current.
The number of BLUEstreak modules that can be operated in parallel is 16. The most
convenient way to parallel large numbers of units is to connect multiple BLUEstreak 19-
inch rack power shelves in parallel.
Document Number: BLUESTREAK-MAN Rev. 6
+VOUT (P4,5,6)
+Sense (C1)
Current Share (D2)
-Sense (B1)
-VOUT (P7,8,9)
+VOUT (P4,5,6)
+Sense (C1)
Current Share (D2)
-Sense (B1)
-VOUT (P7,8,9)
+VOUT (P4,5,6)
+Sense (C1)
Current Share (D2)
-Sense (B1)
-VOUT (P7,8,9)

Figure 8 - Connection Diagram for Parallel Operation

INSTALLATION & OPERATING MANUAL
Page 19
BLUESTREAK SERIES
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