Artesyn Centellis 4100 Installation and Use (2015) - Manual (Page 186)

Configuring and Operating the System
Centellis 4100 Installation and Use (6806800D82E) 188
6.5.2 Power Distribution
The shelf has two different power distribution systems. The first is a low power system
(3.4V DC) that provides power to all IPMCs on shelf FRUs (PEM, blower, ATCA-A100). The
second is a high power system (-48V DC) that provides power to all blades, blowers and shelf
managers.
6.5.2.1 Low Power Distribution
The shelf's low power distribution system is used for powering the IPMCs engines of shelf FRUs.
This low power source (3.4V DC) manifests itself in the form of a redundant interconnection.
The first (V_A) is sourced from the ShMC in the J3 location. The second (V_B) is sourced from
the ShMC in the J11 location. The IPMCs are expected to OR the two sources to allow for
redundancy. Current on each source is limited to 1.0A.
The
Figure "Four-PEM Shelf Power Distribution" on page 190
illustrates the low power
distribution system in the shelf.
The low power distribution system allows powering the IPMCs without having to include an
isolated DC-DC converter including all of its related circuitry as defined in the PICMG
specification in each FRU. This is most useful for FRUs such as blowers and alarm boards where
the size essentially prohibits the inclusion of such power conversion circuitries.
6.5.2.2 High Power Distribution
The shelf's high power distribution system is used for powering the blade, ShMCs and blowers.
This high power source (-48V DC - nominal) manifests itself in the form of two sets of
redundant interconnects.
6.5.2.3 Power Interconnect
The first redundant interconnect is made up of the A1 and B1 feeds. The first feed (-48V_A1) is
sourced from the A1 PEM in the leftmost location (as viewed from the rear of the shelf). The
second feed (-48V_B1) is sourced from the B1 PEM to the right of the first. Both feeds are
individually routed to each ShMC, blower and odd numbered slots. The second redundant
interconnect is made up of the A2 and B2 feeds. The third feed (-48V_A2) is sourced from the
A2 PEM (to the right of the B1 PEM). The fourth feed (-48V_B2) is sourced from the B2 PEM (to
the right of the A2 PEM). These feeds only route to the even numbered slots. In both
interconnects, the FRUs are expected to OR the two sources to allow for redundancy.