Bard T24H1 Installation Instructions Manual

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Bard T24H1 Installation Instructions Manual Manual pdf 27 page image

Manual 2100-541DPage 27 of 28TROUBLESHOOTING ECM™ MOTORSCAUTION:Disconnect power from unit before removing or replacingconnectors, or servicing motor. To avoid electric shock fromthe motor’s capacitors, disconnect power and wait at least 5minutes before opening motor.Symptom Cause/ProcedureMotor rocks slightly • This is normal start-up for ECMwhen startingMotor won’t start • Check blower turns by hand• No movement • Check power at motor• Check low voltage (24 Vac R to C) at motor• Check low voltage connections(G, Y, W, R, C) at motor• Check for unseated pins in connectors onmotor harness• Test with a temporary jumper between R - G• Check motor for tight shaft• Perform motor/control replacement check• Perform Moisture Check• Motor rocks, • Check for loose or compliant motor mountbut won’t start • Make sure blower wheel is tight on shaft• Perform motor/control replacement checkMotor oscillates up • It is normal for motor to oscillate with no load& down while being on shafttested off of blowerMotor starts, butruns erratically• Varies up and down • Check line voltage for variation or “sag”or intermittent • Check low voltage connections(G, Y, W, R, C) at motor, unseated pins inmotor harness connectors• Check “Bk” for erratic CFM command (invariable-speed applications)• Check out system controls, Thermostat• Perform Moisture Check• “Hunts” or “puffs” at • Does removing panel or filter reducehigh CFM (speed) “puffing”?- Reduce restriction- Reduce max airflow• Stays at low CFM • Check low voltage (Thermostat) wires anddespite system call connectionsfor cool or heat CFM • Verify fan is not in delay mode; wait untildelay complete• “R” missing/not connected at motor• Perform motor/control replacement check• Stays at high CFM • “R” missing/not connected at motor• Is fan in delay mode? - wait until delay timecomplete• Perform motor/control replacement check• Blower won’t shut off • Current leakage from controls into G, Y or W?Check for Triac switched thermostat or solid-state relayExcessive noise • Determine if it’s air noise, cabinet, duct ormotor noise; interview customer, if necessary• Air noise • High static creating high blower speed?- Is airflow set properly?- Does removing filter cause blower to slowdown? Check filter- Use low-pressure drop filter- Check/correct duct restrictionsSymptom Cause/Procedure• Noisy blower or cabinet • Check for loose blower housing, panels, etc.• High static creating high blower speed?- Check for air whistling through seams inducts, cabinets or panels- Check for cabinet/duct deformation• “Hunts” or “puffs” at • Does removing panel or filter reducehigh CFM (speed) “puffing”?- Reduce restriction- Reduce max. airflowEvidence of Moisture• Motor failure or • Replace motor and Perform Moisture Checkmalfunction has occurredand moisture is present• Evidence of moisture • Perform Moisture Checkpresent inside air moverDo Don’t• Check out motor, controls, • Automatically assume the motor is bad.wiring and connectionsthoroughly before replacingmotor• Orient connectors down so • Locate connectors above 7 and 4 o’clockwater can’t get in positions- Install “drip loops”• Use authorized motor and • Replace one motor or control model # withmodel #’s for replacement another (unless an authorized replacement)• Keep static pressure to a • Use high pressure drop filters some have ½"minimum: H20 drop!- Recommend high • Use restricted returnsefficiency, low static filters- Recommend keeping filtersclean.- Design ductwork for min.static, max. comfort- Look for and recommendductwork improvement,where necessary• Size the equipment wisely • Oversize system, then compensate with lowairflow• Check orientation before • Plug in power connector backwardsinserting motor connectors • Force plugsMoisture Check• Connectors are oriented “down” (or as recommended by equipmentmanufacturer)• Arrange harness with “drip loop” under motor• Is condensate drain plugged?• Check for low airflow (too much latent capacity)• Check for undercharged condition• Check and plug leaks in return ducts, cabinetComfort Check• Check proper airflow settings• Low static pressure for lowest noise• Set low continuous-fan CFM• Use humidistat and 2-speed cooling units• Use zoning controls designed for ECM that regulate CFM• Thermostat in bad location?

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