Advanced Marine Electrics and Electronics Troubleshooting A Manual for Boatowners and Marine Technicians

56 electrical systems troubleshooting

Testing line voltage. The SureTest shows 119 V at the out-

let. Any reading within ±10% of nominal voltage (120 V)

is acceptable.

Testing neutral-to-ground leakage (voltage). The SureTest

shows 0.9 V, which is acceptable.

Testing peak voltage value. The SureTest shows 168.5 V,

which is normal.

Measuring voltage drop with a 15 amp load. The

SureTest shows 15.5%, which is too high; it should be 5%

or less. High readings like this can indicate poor-quality

terminations in the system or undersized wiring.

Testing frequency in Hz. The SureTest shows 60 Hz, which is

the expected result; ±5% is the maximum accepted tolerance.

Checking voltage drop with a 20 amp load. The SureTest

shows 20.7%, which again is too high.

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