1)  Use an amp clamp to check the amp draw on the primary side of the transformer.  Do this with the test loop of wire connected to the transformer.  The amp draw should be equal to the total wattage of the fixtures divided by 120.
300 watts = 2.5 amps
600 watts = 5.0 amps
900 watts = 7.5 amps
1200 watts = 10 amps
1500 watts = 12.5 amps

2)  Check the individual wire runs from the transformer to the landscape lights.  The amp draw should be equal to the total wattage on the run divided by 12.

3)  Check the voltage on each individual “hub” to ensure the proper voltage is being supplied to each group of lights.  The reading at the hub should be between 11.5-12.5 VAC.  This will ensure that each lamp in group of lights will be supplied with 11-12 VAC since there is approximately 0.5VAC loss in the 25’ lead going to each fixture.

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