User Guide

ManualsBrandsZebra Instruments ManualsHVAC SuppliesVariable Speed Zebra - Advanced ECM Motor Diagnostic Tool System

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Table Of Contents

Observe Mode

OBSERVE mode (Green MODE LED) is meant

for you to use when you’re diagnosing if the

equipment is sending the proper signals to the

motor. It is sometimes confusing because a few

manufacturers do not follow the suggested uses

of the signal lines. For instance, one manufac-

turer sends a signal to the motor down the FAN

line when they want the motor to operate at heat

speed. Also, some manufacturers choose to re-

quire the FAN line to be activated any time the

motor should be on; other manufacturers don’t.

Getting used to the signal patterns that occur

on the equipment you service most often will

give you experience in this area.

Note: This tool will not display these signals if

they are not sent in 2.0/2.3 ECM format. One

manufacturer uses special data signals from the

thermostat to the motor on a few of its systems;

a future Zebra tool may help diagnose them.

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