Bose FREESPACE BMA-125 서비스 매뉴얼 - 페이지 2

{카테고리_이름} Bose FREESPACE BMA-125에 대한 서비스 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Bose FREESPACE BMA-125 49 페이지. Business music amplifier 120/230v

SAFETY INFORMATION

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

schematics 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 American National Standards Institute (ANSI)

C101.1 "Leakage Current for Appliances" and Underwriters Laboratories

(UL) 1492 (71). With the unit AC switch first in the ON position and then in

OFF position, measure from a known earth ground (metal water pipe,

conduit, etc.) to all exposed metal parts of the unit (antennas, handle bracket,

metal cabinet, screw heads, 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 0.5 milliampere. Reverse the unit power

cord plug in the outlet and repeat test. ANY MEASUREMENTS NOT WITHIN

THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZARD

THAT MUST BE ELIMINATED BEFORE RETURNING THE UNIT TO THE

CUSTOMER.

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 resistance with an ohmmeter between the

jumpered AC plug and each exposed metallic cabinet part on the unit. When the

exposed metallic part has a return path to the chassis, the reading should be

between 1 and 5.2 Megohms. When there is no return path to the chassis, the

reading must be "infinite". If it is not within the limits specified, there is the poss-

ibility of a shock hazard, and the unit must be repaired and rechecked before it

is returned to the customer.

symbol on