• Visually monitor signal calls from the furnace/air handler circuit boards.
• Interrupt those signals and send the motor any signals you desire, to observe motor operation.
• Get a visual display of motor RPM and the calculated CFM (on most systems).
• Get a visual readout of all 4 system "taps". These selections help set up a system correctly.
• Get a direct readout of the control voltage in the motor (low voltage here causes erratic operation).
• And finally, IF a problem is traced to the motor, one switch press starts an automatic analysis to clearly indicate if the problem is in the motor's electronics, or one of 7 possible winding problems.

NEW
Quickly verify 24V AC with this compact, pen-style tester. A bright LED instantly confirms power. No voltmeter needed, so you can keep your eyes on the test points and move faster on the job.