PMS. In the case of conflicts, the PMS documentation
the battery switchboard and the switchboard control
takes precedence.
panels provides isolation between the ac and dc power
distribution systems.
MAINTENANCE REPAIR LEVELS
28-V DC Power Distribution System
For the LCAC, the maintenance repair levels are
All 28-V dc power is provided from two sources:
divided into the following four categories:
(1) the storage batteries and (2) the transformer/rectifier
(T/R) units. The storage batteries are made up of two
1. Organizational
12-volt batteries connected in series. The T/R units
2. Enhanced organizational
convert 400 Hz/208 V ac to 28 V dc. The 400-Hz load
centers are energized from the APU-driven generators
3. Depot
or from 400-Hz external shore power. The No. 1 and No.
4. Specialized repair facilities
2 primary dc busses are cross connected through the
These repair levels are part of the source, maintenance,
emergency dc power panels. The reverse current relays
function to prevent damage to the T/R units if a T/R unit
and recoverability (SMR) codes for each part,
should fail. When shore power or generator power is
subassembly, and module. The SMR codes are
identified and explained in the Coordinated Shipboard
unavailable, the battery serves as the emergency dc
power source.
Allowance List (COSAL) for the LCAC. Let's briefly
look at each of these levels.
Now that you have read about the LCAC propulsion
control system and the associated components and
systems, let's look at some important aspects involving
Organizational Maintenance
the maintenance of these systems.
Organizational maintenance includes the type of
maintenance actions that are performed on the LCAC
LCAC SYSTEMS MAINTENANCE
craft, afloat. Organizational maintenance consists of all
As with all equipment and systems, the propulsion
the maintenance actions required to maintain the
control systems and related equipment on the LCAC
operational status of the LCAC during deployment.
must be monitored for effective and safe operation.
Monitoring these systems is also a way of providing
Enhanced Organizational Maintenance
early warnings concerning potential trouble areas.
In this section, we will talk about the general
Enhanced organizational maintenance includes the
maintenance and troubleshooting routines you will
maintenance actions that are normal] y performed on the
encounter with the LCAC control systems and equip-
LCAC craft, ashore. This level of maintenance normally
ment. For detailed information concerning the
consists of craft system troubleshooting, component
procedures you should use for removing and replacing
replacement, or part manufacturing. The LCAC craft
specific parts, we recommend you consult the
unit, ashore, is normally a complete repair facility. The
appropriate technical manuals.
only maintenance actions that are not performed at this
facility are those that require a depot or specialized
SCHEDULED MAINTENANCE
facility maintenance.
Scheduled maintenance of the LCAC control
systems includes the procedures you must perform for
Depot Maintenance
preventive maintenance and performance tests. You will
discover that you must accomplish these procedures on
Depot maintenance is normally based at a shore
a scheduled or condition monitoring basis.
facility. This level of maintenance involves the repair or
You can find the appropriate scheduled mainte-
disposition of components, modules, or assemblies that
nance actions in the technical manuals for the specific
are sealed or require major overhaul. Depot
equipment items. Remember, the scheduled mainte-
maintenance also consists of repair procedures that are
nance instructions in these technical manuals are not
not available at the enhanced organizational level and
intended to duplicate the instructions furnished in the
those that are not cost effective at the lower levels.
