P-8-627-34
T O 35C2-3-442-2
TM-07464A-35 TM 5-6115-457-34
a. Install wire harness (4) in chassis
NOTE
assembly (39) and secure in position with
eight screw assemblies (2) and nuts (4).
Solder connections shall be made
b. Assemble electronic components
using solder, Federal Specifica-
assembly (11) and terminal board (34) to
tion QQ-S-571, Sn 60.
bracket (36), then install the assembly in
chassis assembly (39).
c. Install under voltage relay (27),
e. Test precise relay box as outlined
permissive paralleling relay (29), and
underfrequency relay (31) in position using
four each, screw assemblies.
f. Secure cover (1) to chassis assembly
(39), using four screws and washers.
WARNING
Avoid breathing furies generated by
6-200. INSTALLATION. Refer to fig-
Unsoldering/soldering. Eye pro-
ure 6-15 and install the precise relay box
tection is required.
in position using two screws and washers.
d. Refer to figures 6-53 and 1-21 and
Reconnect electrical plug connectors to
connect wire harness leads to componentry.
receptacles J8 and J32.
Section XI. PRECISE GOVERNOR CONTROL UNIT
6-201. GENERAL.
A frequency reference circuit to select
desired frequency for operation.
a. The precise governor control unit
(A23), figure 3-2 is utilized only on pre-
2. A magnetic amplifier to amplify
cise generator sets. The precise gover-
the measured error between the outputs of
nor is an engine speed frequency regulat-
the frequency measuring and frequency
ing unit. It provides high control sensi-
reference circuits. This error signal is
tivity, fast response, and minimum engine
amplified to a level which is usable by the
speed frequency deviations with load
governor actuator.
fluctuations. It senses electrical frequen-
cy and load. Load sensing and sharing
circuitry permits paralleling of more
3. A transistor inverter circuit to
than two generator sets on an isochronous
convert 24 vdc to approximately 1000 hertz
basis.
to power the magnetic amplifier.
b. The precise governor control unit is
the device that senses the change in gen-
4. A throttle position feedback
erator speed (frequency) and as a result,
circuit for governor stability.
commands actuator to move the throttle.
The governor circuits include:
5. Provisions for accepting the load
1. A frequency error detection cir-
measurement unit signals to provide
cuit to measure the exact instantaneous fre-
isochronous parallel operation, and
quency at which the generator is operating.
improved transient response.
Change 8
6-161
