GE Mark VIeS System Manual page 375

10.6.3 Installation
The JPDG is base-mounted vertically on a metal bracket in a cabinet used by the PDM. There is a 50-pin diagnostic
connector, P2, mounted on the bottom of the board. JPDG is attached with four screws using the mounting holes located at the
top and bottom of the module base. Location within the control cabinet is not critical, however, distribution boards are usually
mounted low in the cabinet to facilitate grounding.
The PPDA I/O pack is plugged into connector JA1. It is secured to the JPDG base using an angle bracket, and held in place
with nuts threaded onto studs that are permanently attached to the base for that purpose. Diagnostic feedback inputs from
other distribution boards are routed to JPDG through a 50-pin ribbon cable attached to connector P2.
Input power connections include:
• Either one or two 28 V dc control power input connections through connectors JR and JS. The JPDG has a common 28 V
dc bus.
• 115 or 230 V ac input applied to connector JAC1 only for sensing and diagnostic purpose. The ac voltage is not
distributed on the JPDG.
• One or two 24 V dc wetting power input connections or one or two 48 V dc input connections through connectors JPS1
and JPS2. The JPDG has a common 24/48 V dc wetting voltage bus.
Caution
Attention
Note A battery connected directly as wetting voltage is not supported by the JPDG. If a battery needs to be connected with
the JPDG for wetting power, the required filter, upstream fuse, and rectifier (the same as that used for the JPDE) must be
installed in the panel with proper connections.
PDM Power Distribution Modules
There is a common electrical bus. Only a single voltage (either 24 V dc to both inputs
or 48 V dc to both inputs) can be applied at one time to both inputs through JPS1 and
JPS2, through ORed diodes.
If two dc supplies are connected, external diodes must be used upstream. If external
diodes are not used and the voltage levels between the two supplies differ, one supply
can drag down the other supply. If one supply fails shorted, then the power bus is
likely to also be shorted. Diodes are external to JPDG and may be inside the power
supplies or an external assembly.
Public Information
GEH-6855_Vol_II System Guide 375