Controls, Start-Up, Operation, Service and ... - Climayoreo
Controls, Start-Up, Operation, Service and ... - Climayoreo
Controls, Start-Up, Operation, Service and ... - Climayoreo
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Transducer Troubleshooting — The electronic control<br />
uses 2 suction pressure transducers to measure the suction<br />
pressure of circuits A <strong>and</strong> B. The pressure/voltage characteristics<br />
of these transducers are in shown in Tables 80 <strong>and</strong> 81. The<br />
accuracy of these transducers can be verified by connecting an<br />
accurate pressure gage to the second refrigerant port in the<br />
suction line.<br />
Forcing Inputs <strong>and</strong> Outputs — Many of variables<br />
may be forced both from the CCN <strong>and</strong> directly at the local<br />
display. This can be useful during diagnostic testing <strong>and</strong> also<br />
during operation, typically as part of an advanced third party<br />
control scheme. Please see Appendix A <strong>and</strong> B.<br />
NOTE: In the case of a power reset, any force levels in effect<br />
at the time of the power reset will be cleared.<br />
CONTROL LEVEL FORCING — If any of the following<br />
points are forced with a priority level of 7 (consult CCN literature<br />
for a description of priority levels), the software clears the<br />
force from the point if it has not been written to or forced again<br />
within the timeout periods defined below:<br />
Table 72 — Humidi-MiZer <strong>Service</strong> Analysis (cont)<br />
PROBLEM CAUSE REMEDY<br />
Unit Initiates a Humidi-MiZer<br />
Dehumidification Mode, but<br />
Supply Air Temperature is<br />
Overheating/Overcooling the<br />
Space<br />
Low Sensible Capacity in<br />
Normal Cooling Mode<br />
Modulating Valves Not<br />
Functioning Properly<br />
Supply air setpoint for cooling is too<br />
high/low<br />
Evaporator discharge temperature<br />
(CCT) or Supply air temperature (SAT)<br />
thermistor is reading incorrectly.<br />
Valve controlling gas bypass around<br />
the condenser is not functioning<br />
properly<br />
Valve controlling refrigerant flow to the<br />
condenser is not functioning properly<br />
Modulating valves are not calibrated<br />
properly<br />
Unit control software indicates a<br />
Humidi-MiZer Reheat Mode, but the<br />
3-way valve is not functioning properly<br />
Unit is not sized to meet the load at the<br />
current entering air <strong>and</strong> outdoor<br />
conditions.<br />
TemperaturesAIR.TOAT Outside Air Temperature 30 minutes<br />
TemperaturesAIR.TRAT Return Air Temperature 3 minutes<br />
TemperaturesAIR.TSPT Space Temperature 3 minutes<br />
InputsRSETSP.RS Static Pressure Reset 30 minutes<br />
InputsREL.HOA.RH Outside Air Relative Humidity 30 minutes<br />
InputsAIR.QOAQ Outside Air Quality 30 minutes<br />
93<br />
Check the unit supply air set point for cooling operation. This is the<br />
temperature that the valves will modulate to meet during a dehumidification<br />
mode.<br />
See "Thermistor Troubleshooting" on page 91<br />
Check if SAT thermistor is in a location that is measuring stratified<br />
air<br />
See "Modulating Valves Not Functioning Properly"<br />
See "Modulating Valves Not Functioning Properly"<br />
See "Modulating Valves Not Functioning Properly"<br />
See "3-Way Valve Malfunction"<br />
Check product data tables or ECAT for rated capacity at current<br />
entering air <strong>and</strong> outdoor conditions.<br />
Valve controlling gas bypass around See "Modulating Valves Not Functioning Properly"<br />
the condenser is stuck in an open position<br />
or leaking<br />
Valve controlling refrigerant flow to the See "Modulating Valves Not Functioning Properly"<br />
condenser is stuck in a position less<br />
than 100% open<br />
General cooling mode problem See "Cooling Troubleshooting," Table 71.<br />
Faulty wire connections Check that the valve wiring is properly connected from the valve,<br />
entering the control box <strong>and</strong> at the EXV board<br />
EXV board malfunction Check alarm history for A169 (Expansion Valve Control Board<br />
Comm Failure)<br />
Valve is stuck open/closed Use <strong>Service</strong> Test to manually manipulate the valve position <strong>and</strong><br />
confirm supply air temperature changes during operation.<br />
Run valve calibration through <strong>Service</strong> Test<br />
Check valve motor for open or short circuited windings. Shut down<br />
power to the unit <strong>and</strong> connect Ohmmeter probes across the black<br />
<strong>and</strong> white terminals. Resistance should measure 75 Ohms ±10%.<br />
Next, connect Ohmmeter probes across the red <strong>and</strong> green terminals.<br />
Resistance should measure 75 Ohms ±10%. The meter<br />
should not show an "open" or a "short" when a winding leg is measured.<br />
If either occurs, replace the valve.<br />
Valve is not calibrated properly Run valve calibration through <strong>Service</strong> Test<br />
Run Status Menu — The Run Status menu provides the<br />
user important information about the unit. The Run Status table<br />
can be used to troubleshoot problems <strong>and</strong> to help determine<br />
how <strong>and</strong> why the unit is operating.<br />
AUTO VIEW OF RUN STATUS — The Auto View of Run<br />
Status display table provides the most important unit information.<br />
The HVAC Mode (Run StatusVIEW HVAC) informs<br />
the user what HVAC mode the unit is currently in. Refer<br />
to the Modes section on page 40 for information on HVAC<br />
modes. The occupied status, unit temperatures, unit set points,<br />
<strong>and</strong> stage information can also be shown. See Table 82.<br />
Run StatusVIEWHVAC — Displays the current HVAC<br />
Mode(s) by name. HVAC Modes include:<br />
OFF VENT HIGH HEAT<br />
STARTING UP HIGH COOL FIRE SHUT DOWN<br />
SHUTTING DOWN LOW COOL PRESSURIZATION<br />
DISABLED UNOCC FREE COOL EVACUATION<br />
SOFTSTOP REQUEST TEMPERING HICOOL SMOKE PURGE<br />
REM SW DISABLE TEMPERING LOCOOLDEHUMIDIFICATION<br />
COMP STUCK ON TEMPERING VENT RE-HEAT<br />
TEST LOW HEAT<br />
Run StatusVIEWOCC — Displays the current occupancy<br />
status of the control.<br />
Run StatusVIEWMAT — Displays the current value for<br />
mixed-air temperature. This value is calculated based on<br />
return-air <strong>and</strong> outside-air temperatures <strong>and</strong> economizer damper<br />
position.