TM 11-6625-2735-14-1
Section 2—475 Service
OPERATING INFORMATION
PRELIMINARY INSTRUCTIONS
Introduction
This section of the manual is intended to allow the
operator to become familiar with the instrument’s power
requirements, functions of controls and connectors, and
how to obtain a few basic displays.
Safety Information
This instrument may be damaged if operated with
the Line Voltage Selector Switch or the Regulating
Range Selector set for the wrong applied line
voltage. Please read the following instructions
before operating to be sure that the requirements for
instrument power and user safety are met.
Power Cord Conductor Identification
Conductor
Color Alternate Color
Ungrounded (Line)
Brown
Black
Grounded (Neutral)
Blue White
Grounding (Earthing) Green-Yellow Green-Yellow
This instrument is designed to operate from a single-
phase power source with one of the current-carrying
conductors (the neutral conductor) at ground (earth)
potential. Operation from power sources where both
current-carrying conductors are live with respect to
ground (such as phase-to-phase on a 3-wire system) is not
recommended, since only the line conductor has over-
current (fuse) protection within the instrument.
This instrument has a 3-wire power cord with a 3-
terminal polarized plug for connection to the power
source and safety-earth. The ground terminal of the plug
is directly connected to the instrument frame. For electric-
shock protection, insert this plug in a mating outlet with a
safety-earth contact. If a 3-to-2 wire adapter is used to
connect this instrument to a 2-wire ac power system, be
sure to connect the ground lead of the adapter to earth
(ground). Failure to complete the ground system may
allow the chassis of this instrument to be elevated above
ground potential and pose a shock hazard.
Operating Power Sources
This instrument can be operated from either a 115 volt
or 230 volt nominal line voltage source, 48 to 440 Hertz.
The Line Voltage Selector switch in the instrument
converts the instrument from a one nominal operating
voltage to the other. The Regulating Range Selector
assembly on the instrument rear panel selects 1 of 3 regu-
lating ranges for each nominal line voltage, and also con-
tains the line fuse for overload protection. The instrument
can also be operated from a 12 vdc or 24 vdc power source.
Line Voltage and Regulating Range
To select the correct nominal line voltage, regulating
range and line fuse, proceed as follows:
1. Disconnect the instrument from the power source.
2. Set the Line Voltage Selector switch (located near
the right rear of instrument) to indicate the desired
nominal line voltage.
3. Loosen the 2 captive screws that hold the cover on
the Regulating Range Selector assembly; then pull on the
cover to remove.
4. Check Table 2-1 for the recommended rating of the
line fuse to be used with the desired nominal line voltage.
Check the fuse in the selector switch cover for the
recommended rating or install a fuse with the recommend-
ed rating. The instrument Accessory Pouch should con-
tain a spare fuse for each nominal Iine voltage at anytime.
TABLE 2-1
Regulating Ranges
Regulating Range
Range Selector 115 Volts
230 Volts
Switch Position
Nominal
Nominal
LO (Switch bar in 99 to 121 volts
198 to 242 volts
lower holes)
M (Switch bar in 103.5 to 126.5 V 207 to 253 V
middle holes)
HI (Switch bar in 108 to 132 volts 216 to 264 volts
upper holes)
Fuse Rating
6.75 A 3AG
Fast-blow
1.5 A 3AG
Fast-blow
Change 1 2-1
To Next Page
Loading...
Need help?
General
