1-7. How to Find a Good Earth Ground.
1) A cold-water pipe is a guaranteed earth ground; the cover-plate
retaining screw on most AC outlet boxes is also at earth ground.
2) If the retaining screw is to be used as your earth ground, verify
that it is at ground by measuring the resistance between it and a
cold-water pipe with an ohmmeter. The reading should be zero ohms.
3) If a cold-water pipe is not accessible, connect a 60- to 100-watt trouble-
light (not a neon lamp) between the hot side of the receptacle and the
retaining screw. Try both slots, if necessary, to locate the hot side on
the line; the lamp should light at normal brilliance if the screw is at
ground potential (see Figure 3).
Figure 3. Checking for earth ground.
The servicing of these boards requires special precautions. It is strongly
recommended to use Lead Free Solder material in order to guarantee
optimal quality of new solder joints.
1-8. Lead Free Information
The circuit boards used in these models have been processed using Lead
Free Solder. The boards are identified by the LF logo located close to the
board designation.
Figure 4: LF Logo Figure 5: LF logo on circuit board
11
SAFETY NOTES
SYSSET
2023/11/2806:39:49(GMT+09:00)
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