Specifications

POWERCASSETTE FRONT-END

OPERATING MANUAL

13.0 PARALLEL OPERATION

13.1 Parallel Connection. Two or more PowerCassettes can be operated in

parallel by connecting their outputs in parallel and connecting their current

share terminals, together (pin 18). The PowerCassette racks permit conve-

niently operating two or three units in parallel in either a 1+1 or 2+1 redun-

dant mode or non-redundant mode.

13.2 Redundant Operation. Connecting two PowerCassettes 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 PowerCasssette 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 the ORing diode on the

output. 1+1 redundancy with quick replacement of a failed unit results in

virtually infinite MTBF. 2+1 redundancy works the same way except that the

full load is carried by two out of three units.

13.3 Non-Redundant Operation. Higher output load currents can be realized by

operating two or three units in the non-redundant mode to achieve up to 1600

watts for two units or 2400 watts for three units. 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 remain-

ing unit(s), which will go into current limit. The failed unit can be quickly re-

placed, however, without turning the power off (hot-swap) to restore load

current.

14.0 COMPATIBLE 19-INCH RACKS

14.1 There are two 19-inch compatible racks. One holds two PowerCassette

TPCM units and the other holds three. See Figures 9 and 10. These racks

have the following features:

Standard 19-Inch Racks

Only 1U High

Hot-Swap Operation

Holds Two or Three TPCM Units

Class B EMI Input Filter

Up to 1600W or 2400W Non-Redundant