Safety Test - Mackie SRM450 Service Manual

Safety test

You must perform the following leakage test before returning the unit 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 floating. 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 unit
before returning it to your customer.
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