Make your clamp-on ammeter more useful. Make one of these:
This is a 2' section of 12ga 3-conductor cord with a plug and socket attached, and a 6" section of the jacket and filler cord removed to expose the individual conductors. Plug this in the wall, plug the device you want to measure the current draw into the other end. You can make a bunch of different measurements:
For simple current draw, clamp the meter around the black (hot) wire. The current drawn will show on the meter. If the current is small and near the lower limit of the ammeter, coil the wire. For each turn, divide the reading by the number of turns for the reading. If you loop the wire three times, divide the reading by 3 for the actual value. Only coil the single conductor for this test.
For a DC imbalance test, connect as above but switch the meter to read amps DC instead. This is useful for switching supplies, speed controls and dioded lamps and the like. Sometimes a device will draw a small indicated AC current, but the device is rectifying the voltage and using only one half of the AC wave. Good for troubleshooting.
Ground fault test: Clamp the meter around the hot and neutral only (black and white here). If you read a significant (non-zero) value, move the meter to the green conductor. If you read the same value, a portion of the load is being diverted through the grounding conductor. This is a big safety issue. Good for finding insulation faults in motors.
Set the meter for inrush or peak to find the maximum current drawn by the device. While a motor might only draw 4 amps while running, don't be surprised to find ten times that value when it is starting. Use the test configuration for basic measurements. Useful for finding out why the appliance is tripping breakers intermittently. Not all clamp meters have this function.
