from one light or the other, allowing determination of
1-3. PURPOSE.
phase rotation from the illuminated light.
1-9. INSTALLATION COMPONENTS.
slaving, power supply, and ground checks of various
1-10.
Three extension lead assemblies, and seven
include the checking of the frequency and voltage of
adapter assemblies, consisting of male and female
single-phase 120-volt, 400 cycle alternating current; the
electrical connectors are supplied with the P-1 tester.
voltage of 28-volt direct current; and the phase rotation
Each lead and adapter assembly is designed to
of three phase, 115-volt 400 cycle alternating current.
accommodate a specific slaved gyro magnetic compass
for testing. (See table 4-1.)
1-6. FREQUENCY METER. The frequency meter M-1
is a vibrating reed type instrument designed to read the
frequency of the input voltage. Tests set with serial
numbers 170 and above are furnished with an
instrument which will indicate the frequency spectrum
from 380 to 420 Hz in 4 Hz intervals. Earlier units with
serial numbers up to 169 were supplied with an
instrument with a range of 360 to 440 Hz with scale
calibrations in steps of 8 HZ. The frequency meter is
hooked directly across the power source to be checked
when switch No. 1 is at position 1.
1-7. A-C MILLIAMMETER. The a-c milliammeter M-2
is a rectifier type instrument with a basic movement of 0
to 1.0 milliamperes and a scale specifically calibrated
fur this equipment.
1-8. PHASE ROTATION LIGHT CIRCUIT. The pilot
Iights (marked ABC and CBA), indicating phase rotation,
Figure 1-1. Slaved Gyro Magnetic Compass Field
are connected in combination with the condenser, which
shifts the phase at pin C of the four pin panel receptacle
Tester. Type P-1.
P-l to cancel the voltage at pin A or B, depending upon
the phase rotation of the three phase supply. This
cancellation removes the voltage
Change 4 7
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