Sony DVCAM DSR-60, Service Manual

Page: 120 / 324

3-44 DSR-80/80P/60/60P
3-15. SAFETY CHECK-OUT
(UC MODEL ONLY)
After correcting the original service problem, perform the
following safety checks before releasing the set to the
customer :
Check the metal trim, “metallized” knobs, screws, and all
other exposed metal parts for AC leakage. Check leakage
as described below.
LEAKAGE TEST
The AC leakage from any exposed metal part to earth
ground and from all exposed metal parts to any exposed
metal part having a return to chassis, must not exceed
0.5 mA (500 microampers). Leakage current can be
measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229
or RCA WT-540A. Follow the manufacturers’
instructions to use these instruments.
2. A battery-operated AC milliammeter. The Data
Precision 245 digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means
of a VOM or battery-operated AC voltmeter. The
“limit” indication is 0.75 V, so analog meters must
have an accurate low-voltage scale. The Simpson 250
and Sanwa SH-63Trd are examples of a passive VOM
that is suitable. Nearly all battery operated digital
multimeters that have a 2 V AC range are suitable.
(See Fig. A)
Fig A. Using an AC voltmeter to check AC leakage.
To Exposed Metal
Parts on Set
1.5 k
Z
0.15
u
F
AC
voltmeter
(0.75 V)
Earth Ground