Watlow QPAC-01 User Manual

Contents

Watlow QPAC-01 User Manual Manual pdf 28 page image

28 QPAC User's Manual AppendixSymptom Probable Cause Corrective ActionNo output Fuses blown Check and replace fusesIncorrect input wiring See “Input Wiring,” p. 18-23.Incorrect input signal Check temp. control output.Input signal reversed See “Input Wiring,” p. 18-23.Input signal not adjusted See “Bias and Gain Adjustment"p. 25-26.Wrong or missing control card See “Input Wiring,” p. 18-23.Transformer wiring Check transformer connections.Missing load wiring See “Power and Load Wiring,”p. 14-17. The SCR(s) will notfunction without a load.Heatsink Clogged or non-operational fan Check fan, power, and clean iftemperature necessary. Check for shortedexceeded thermostat, replace fan or thermo-187°F (86°C) stat as necessary. #27-0005thermostat is normally open andcloses on temperature rise.Transformer Incorrect transformer Check product & transformerhot labels.Uncontrolled Bad control card, or bias and Unplug control card, try again.output full ON gain out of adjustment Readjust bias & gain.Bad transformer Unplug transformer wire andtry again.Bad power base If full ON or half ON outputpresent with no control cardand no transformer, powerbase is bad, replace.Unbalanced Incorrect phase rotation See "Phase Rotation Adjust.,"output p. 25.(QPAC-32& QPAC-33)QPAC TroubleshootingA technician can isolate a system problem by first checking if the load is good,and the line voltage and temperature signals are present and correct. If theabove is true, then the power control may be the problem. This problem maybe with the QPAC's control card, transformer or power base. Use Table 8 toassist with troubleshooting.The QPAC-33 has four LEDs for diagnostic indication. During normal opera-tion, all four LEDs will be illuminated.• Power ON Yellow LED is ON when power is applied to the control.• Phase Loss Yellow LED is ON when all three phases of line voltageare present. LED will be OFF if one phase is low or lost.• Phase Rotation Yellow LED is ON when correct voltage phase exists,even when load is not wired. LED will be OFF when twophases are rotated, and when one phase is missing.• Phase Lock Loop Yellow LED is ON when phase lock loop circuit issynchronized. LED can go OFF from noisy power line orif the phase synchronizing circuitry fails. Check powerquality, then repair or replace power base.QPAC-33 DiagnosticsTroubleshootTable 8-QPAC Troubleshoot-ing Guide