TM 55-4920-328-13
CHAPTER 5
CHECKOUT AND TROUBLESHOOTING
Section I. GENERAL INFORMATION
5-1. Scope.
This chapter contains the information for checkout and
troubleshooting of METS components, subsystems, and
systems. In some cases, an operational check of a
functional loop may be accomplished to isolate a
defective component. Troubleshooting of electrical
systems and circuits may be accomplished using the
electrical schematic diagrams in this section. Figures
FO-2 and FO-3 depict the ac power generation control
and distribution system. Figure FO-4 provides the
interface test points for isolation of trouble in power and
signal circuitry. Figures FO-5 through FO-27 provide
schematic information on the circuits contained in the
system. Table 5-4 lists troubleshooting data.
5-2. References.
To
aid
the
technician
during
checkout
and
troubleshooting, frequent reference must be made,
when required, to another paragraph or section of this
technical manual to aid in understanding system
operation or to provide specific operating limits with a
known input. Chapter 1 contains the description and
leading particulars of all significant METS components.
When appropriate, a brief functional description of the
component is provided. Chapter 2 contains information
on the functions of controls and indicating devices in the
system, and provides initial indication values when the
electrical systems are energized with no input signal.
Chapter 2 also provides detailed procedures for
preliminary system checkout to enable the operator to
determine system capability prior to firing an engine.
Inspection of the system is limited to a visual inspection
of components for obvious damage. This information is
contained in chapter 6. Calibration will be performed in
accordance with TB 55-4920-328-50.
Section II. CHECKOUT PROCEDURES
5-3. Electrical Checkout Procedures.
Checkout of METS system electrical components may
be accomplished without the use of special tools or
special test equipment; only common test equipment is
required. In most instances, checkout may be
performed without removal of the component from the
system; only electrical isolation is required. A source of
system ac or dc electrical power, and, in some cases, a
source of low magnitude dc input power, is required for
simulated signal input and for component excitation.
Electrical component checkout procedures are defined
in the following test.
5-4. No. 1 Power Control Panel Assembly 5A1.
Checkout the operation of relay (27C, figure 7-19) and
adjust as follows:
NOTE
The relay (K6) shown in schematic,
figure FO-2, located in the back of
this manual, provides over-voltage
protection to the various auxiliary
circuits.
a. Disconnect J3 on the power control panel No. 1 to
remove console power to the assembly.
b. Connect the output of a variac to TP1 and TP4,
figure 5-1. Ensure the variac output is set for zero volts.
c. Connect an AC voltmeter (0-150 volts) to TP2 and
TP5.
d. Connect an ohmmeter, set on the X1 scale, to TP3
and TP6.
5-1
