Hanwha Techwin TNO-4030T Service Manual Download Page 4

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Precautions_

1) Before returning an instrument to the customer, always make a safety check of the entire instrument, including,
but not limited to, the following items:

(1) Be sure that no built-in protective devices are defective or have been defeated during servicing.

(2) Protective shields are provided to protect both the technician and the customer. Correctly replace all missing protective

shields, including anyremoved for servicing convenience.

(3) When reinstalling the chassis and/or other assembly in the cabinet, be sure to put back in place all protective devices, in-

cluding, but not limited to, nonmetallic control knobs, insulating fish papers, adjustment and compartment covers/shields, and
isolation resistor/capacitor networks. Do not operate this instrument or permit it to be operated without all protective devices
correctly installed and functioning.

(4) Be sure that there are no cabinet openings through which adults or children might be able to insert their fingers and contact

a hazardous voltage. Such openings include, but are not limited to, excessively wide cabinet ventilation slots, and an im-
properly fitted and/or incorrectly secured cabinet back cover.

(5) Leakage Current Hot Check-With the instrument completely reas-

sembled, plug the AC line cord directly into a 230V(220V ~ 240V)
AC outlet. (Do not use an isolation transformer during this test.) Use a
leakage current tester or a metering system that complies with Amer-
ican National Standardsp institute (ANSI) C101.1 Leakage Current
for Appliances and Underwriters Laboratories (UL) 1270 (40.7). With
the instrument’s AC switch first in the ON position and then in the
OFF position, measure from a known earth ground (metal water pipe,
conduit, etc.) to all exposed metal parts of the instrument (anten-
nas, handle brackets, metal cabinets, screwheads, metallic overlays,
control shafts, etc.), especially any exposed metal parts that offer an
electrical return path to the chassis. Any current measured must not
exceed 0.5mA. Reverse the instrument power cord plug in the out-
letand repeat the test. See Fig. 1-1. Any measurements not within the
limits specified herein indicate a potential shock hazard that must be
eliminated before returning the instrument to the customer.

(4) Insulation Resistance Test Cold Check

(1) Unplug the power supply cord and connect a jumper wire between the two prongs of the plug.
(2) Turn on the power switch of the instrument.
(3) Measure the resistance with an ohmmeter between the jumpered AC
plug and all exposed metallic cabinet parts on the instrument, such as
screwheads, antenna, control shafts, handle brackets, etc. When an ex-
posed metallic part has a return path to the chassis, the reading should
be between 1 and 5.2 megohm. When there is no return path to the
chassis, the reading must be infinite. If the reading is not within the limits
specified, there is the possibility of a shock hazard, and the instrument
must be repaired and rechecked before it is returned to the customer.
See Fig. 1-2.

2) Read and comply with all caution and safety related notes on or inside the cabinet, or on the chassis.

3) Design Alteration Warning-Do not alter or add to the mechanical or electrical design of this instrument. Design

alterations and additions, including but not limited to, circuit modifications and the addition of items such as
auxiliary audio output connections, might alter the safety characteristics of this instrument and create a hazard
to the user. Any design alterations or additions will make you, the servicer, responsible for personal injury or
property damage resulting therefrom.

4) Observe original lead dress. Take extra care to assure correct lead dress in the following areas:

(1) near sharp edges, (2) near thermally hot parts (besure that leads and components do not touch

1. Precautions

1-1 Safety Precautions

Fig. 1-1 AC Leakage Test

Fig. 1-2 Insulation Resistance Test

DEVICE
UNDER

TEST

TEST ALL

EXPOSED METER

SURFACES

READING SHOULD