Bose Companion 3 Series II Посібник з експлуатації - Сторінка 3

1. Parts that have special safety characteristics are identified by the

or by special notes on the parts list. Use only replacement parts that have critical characteristics

recommended by the manufacturer.

2. Make leakage current or resistance measurements to determine that exposed parts are acceptably

insulated from the supply circuit before returning the unit to the customer. Use the following checks to

perform these measurements:

A. Leakage Current Hot Check- With the unit completely reassembled, plug the AC line cord directly

into a 120V AC outlet. (Do not use an isolation transformer during this test). Use a leakage current

tester or a metering system that complies with the American National Standards Institute (ANSI)

C101.1 "Leakage Current for Appliances" and the Underwriters Laboratories (UL) 6500/IEC 60056

paragraph 9.1.1. With the unit AC switch first in the ON position and then in the OFF position, mea-

sure from a known earth ground (metal waterpipe, conduit, etc.) to all exposed metal parts of the unit

(antennas, handle bracket, metal cabinet, screwheads, metallic overlays, control shafts, etc.) espe-

cially any exposed metal parts that offer an electrical return path to the chassis. Any current measured

must not exceed 0.5 milliamp. Reverse the unit power cord plug in the AC outlet and repeat the test.

ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL

SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RETURNING THE UNIT TO THE CUS-

TOMER.

B. Insulation Resistance Test Cold Check- (1) Unplug the power supply and connect a jumper wire

between the two prongs of the plug. (2) Turn on the power switch of the unit. (3) Measure the resis-

tance with an ohmmeter between the jumpered AC plug and each exposed metallic cabinet part on

the unit. When testing 3 wire products, the resistance measured to the product enclosure should be

between 2 and infinite MOhms. Also, the resistance measured to exposed input/output connectors

should be between 4 and infinite MOhms. When testing 2 wire products, the resistance measured to

exposed input/output connectors should be between 4 and infinite MOhms. If it is not within the limits

specified, there is the possibility of a shock hazard, and the unit must be repaired and rechecked

before it is returned to the customer.

Electrostatic Discharge Sensitive (ESDS)

This unit contains ESDS devices. We recommend the following precautions when repairing, replacing

or transporting ESDS devices:

•

Perform work at an electrically grounded work station.

•

Wear wrist straps that connect to the station or heel straps that connect to conductive floor mats.

•

Avoid touching the leads or contacts of ESDS devices or PC boards even if properly grounded.

Handle boards by the edges only.

•

Transport or store ESDS devices in ESD protective bags, bins, or totes. Do not insert unprotected

devices into materials such as plastic, polystyrene foam, clear plastic bags, bubble wrap or plastic

trays.

Safety Information

Device Handling

symbol on the schematics