Active Speaker Safety Test - Mackie ART300A Service Manual

ART300A Service Manual

Active speaker safety test

You must perform the following leakage test before returning any active speakers to your
customer. Take every safety precaution to protect yourself while doing this test.
1. Make a small loading RC circuit as shown in the diagram below, and connect the
AC volt meter between the AC power source ground and any exposed metal on
the unit under test.
2. Connect the unit under test to an AC power source using a ground-lift adaptor,
leaving the unit's safety ground fl oating. Turn the unit on.
3. The meter reading should be less than 750mVAC (note: this is equivalent to 0.5mA
of leakage current).
4. Flip the plug over in the receptical so the hot and neutral are swapped.
Verify that the reading is still less then 750mVAC.
5. If either reading is greater than 750mVAC, then you must investigate and repair
the speaker before returning it to your customer.
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