Figure 7-2.--Excitation control panel (internal view).
Overvoltage limiter (OVL)
Allison 501-K34 is found specifically on the DDG-51
class ships.
Interface module (IFM)
Manual voltage adjust (MVA)
Excitation Control Panel (EXCOP)
Motor-operated potentiometer (MOP)
On the DDG-51 class ships, the EXCOP on the
Diode fault detector (DFD)
Allison 501-K34 replaces the governor control unit
Failure detector module (FDM)
(GCU) on the Allison 501-K17 model found on the
CG-, DD-, and DDG-993 class ships.
Current limiter (CL)
The DDG-51's EXCOP is a stainless-steel housing
Figure 7-2 is an illustration of the EXCOP showing
located on the module base. It receives speed, voltage,
the relative location of these components, which we
and current sensing signals from the SSGTG output. It
will briefly describe in the following paragraphs.
also receives ac power from the PMA. It uses these
Please refer to figure 7-2 as you read the following
outputs in combination with performance control signals
sections.
to regulate the following major components:
Automatic voltage regulator (AVR)
AUTOMATIC
VOLTAGE
REGULATOR
ASSEMBLIES. There are two AVR assemblies in the
Power control module (PCM)
