HP 400D Operating And Service Manual

T.O. 33A1-12-349-1
Section IL
Paragraphs 2-1 to 2-11
SECTION II
INSTALLATION
2-1. UNPACKING AND INSPECTION.
2-2. There are no special precautions for unpacking
the voltmeter. Save the shipping carton and packing
materials for possible storage or reshipment. When
unpacking, inspect instrument and packing materials
for signs of damage in shipment. Make an operation
check as directed in paragraph 2-10 to determine if
performance is satisfactory. If there is any indication
of damage, immediately file a claim with the transport
service used or other cognizant authority.
2-3. LINE VOLTAGE REQUIREMENT.
2-4. The voltmeter is wired at the factory for use on
115-volt a-c power. This voltage may vary +10% without
adverse effect upon voltmeter performance. The volt-
meter can be wired for use on 230-volt a-c power by
reconnecting the dual primary windings on the power
transformer as shown in the schematic diagram in
Section V. When using 230-volt power, change from
a l-amp to a 1/2-amp slow-blow fuse. If necessary,
provide an adapter for attaching the standard 115-volt
plug on the voltmeter to the 230-volt outlet.
2-5. POWER LINE CONNECTION.
2-6. The three-conductor power cable on the voltmeter
is terminated in a polarized three-prong male connector.
The third contact is an offset round pin added to a stand-
ard two-blade connector, which grounds the instrument
chassis when used with the appropriate receptacle.
To connect this plug in a standard two-contact receptacle,
use an adapter. The chassis ground connection is
brought out of the adapter in a green pigtail lead for
connection to a suitable ground.
2-7. The power plug normally supplied with the volt-
meter is made of molded rubber and is an integral
part of the power cable. On certain military contracts,
a modification of the Model 400D, termed the H02-400D,
is equiped with a removable plug having the same pin
configuration but constructed of corrosion-resistant
material. In all other respects the H02-400D is the
same as the Model 400D and carries the same Federal
Stock Number.
00102-2
The lower INPUT and OUTPUT signal terminals
on the panel of the voltmeter are connected
directly to the chassis of the voltmeter. Any
voltage applied to the lower terminal will be
shorted directly to ground. If the ground con-
nection in the power cord is disconnected by
use of an adapter, the entire voltmeter cabinet
will carry whatever potential is applied to the
lower terminal and may be a hazard to the
operator.
2-8. INSTALLATION.
2-9. The voltmeter is a portable instrument requiring
no permanent installation. The voltmeter is for bench-
top operation, standing on its rubber feet with its front
panel near the vertical plane. A bail is provided for
raising the front of the cabinet to obtain a better viewing
angle.
2-10. OPERATION CHECK.
2-11. The voltmeter is ready for use as received from
the factory. The simple check described below can be
made by incoming inspectors to determine if electrical
damage was incurred in shipment. If more complete
proof of instrument performance is required, the over-all
performance check described in paragraph 5-22 must be
used. Make a simple performance check as follows:
a. Connect voltmeter to the power line through a
variable transformer. Set transformer for 115 volts,
turn on and allow a five-minute warmup.
b. Measure any sine wave voltage, excepting the power
line, from 0.01 to 300 volts whose exact voltage is known.
Note that the lower INPUT terminal is connected to the
power line ground.
c. While making the above measurement, adjust the
line voltage from 103 to 127 volts, The reading on the
meter must not change by more than the width of the
pointer.
2-1

HP 400D Specifications

General

Brand	HP
Model	400D
Category	Measuring Instruments
Language	English