Forcing Inputs and Outputs — Many variables may be forced both from the CCN and directly at the local display. This can be useful during diagnostic testing and also during operation, typically as part of an advanced third party control scheme. See Appendices A and B.
NOTE: In the case of a power reset, any force in effect at the time of the power reset will be cleared.
CONTROL LEVEL FORCING — If any of the following points are forced with a priority level of 7 (consult CCN litera- ture for a description of priority levels), the software clears the force from the point if it has not been written to or forced again within the timeout periods defined below:
Temperatures→AIR.T→OAT | Outside Air Temperature | 30 minutes |
Temperatures→AIR.T→RAT | Return Air Temperature | 3 minutes |
Temperatures→AIR.T→SPT | Space Temperature | 3 minutes |
Inputs→RSET→SP.RS | Static Pressure Reset | 30 minutes |
Inputs→REL.H→OA.RH | Outside Air Relative Humidity 30 minutes | |
Inputs→AIR.Q→OAQ | Outside Air Quality | 30 minutes |
Run Status Menu — The Run Status menu provides the user important information about the unit. The Run Status table can be used to troubleshoot problems and to help determine how and why the unit is operating.
AUTO VIEW OF RUN STATUS — The Auto View of Run Status display table provides the most important unit informa- tion. The HVAC Mode (Run Status→VIEW→HVAC) in- forms the user what HVAC mode the unit is currently in. Refer to the Modes section on page 32 for information on HVAC modes. The occupied status, unit temperatures, unit set points, and stage information can also be shown. See Table 105.
Run Status→VIEW→HVAC — Displays the current HVAC Mode(s) by name. HVAC Modes include:
OFF | VENT | HIGH HEAT |
STARTING UP | HIGH COOL | FIRE SHUT DOWN |
SHUTTING DOWN | LOW COOL | PRESSURIZATION |
DISABLED | UNOCC FREE COOL | EVACUATION |
SOFTSTOP REQUESTTEMPERING HICOOL SMOKE PURGE | ||
REM SW DISABLE | TEMPERING LOCOOL |
|
COMP STUCK ON | TEMPERING VENT |
|
TEST | LOW HEAT |
|
Run Status→VIEW→OCC — This variable displays the cur- rent occupancy status of the control.
Run Status→VIEW→MAT — This variable displays the cur- rent value for
Run Status→VIEW→EDT — This variable displays the cur- rent evaporator discharge air temperature during Cooling modes. This value is read at the supply air thermistor location (or at cooling coil thermistor array if unit is equipped with hy- dronic heating coil).
Run Status→VIEW→LAT — This variable displays the cur- rent
Run Status→VIEW→EC.C.P — This variable displays the current economizer control point value (a target value for air temperature leaving the evaporator coil location).
Run Status→VIEW→ECN.P — This variable displays the current actual economizer position (in percentage open).
Run Status→VIEW→CL.C.P — This variable displays the current cooling control point (a target value for air temperature leaving the evaporator coil location).
Run Status→VIEW→C.CAP — This variable displays the current amount of unit cooling capacity (in percent of maximum).
Run Status→VIEW→HT.C.P — This variable displays the current heating control point, for use with staged gas control option only (a target value for air temperature leaving the sup- ply duct).
Run Status→VIEW→HT.ST — This variable displays the current number of heating stages active (for staged gas control option only). Compare to following point.
Run Status→VIEW→H.MAX — This variable displays the maximum number of heat stages available for this model. ECONOMIZER RUN STATUS — The Economizer Run Status display table provides information about the economizer and can be used to troubleshoot economizer problems. See Table 106. The current position, commanded position, and whether the economizer is active can be displayed. All the disabling condi- tions for the economizer and outside air information is also displayed.
COOLING INFORMATION — The Cooling Information run status display table provides information on the cooling opera- tion of the unit. See Table 107.
Current Running Capacity (C.CAP) — This variable repre- sents the amount of capacity currently running as a percent. Current Cool Stage (CUR.S) — This variable represents the cool stage currently running.
Requested Cool Stage (REQ.S) — This variable represents the requested cool stage. Cooling relay time guards in place may prevent the requested cool stage from matching the current cool stage.
Maximum Cool Stages (MAX.S) — This variable is the max- imum number of cooling stages the control is configured for and capable of controlling.
Active Demand Limit (DEM.L) — If demand limit is active, this variable will represent the amount of capacity that the control is currently limited to.
Capacity Load Factor (SMZ) — This factor builds up or down over time
Next Stage EDT Decrease (ADD.R) — This variable repre- sents (if adding a stage of cooling) how much the temperature should drop in degrees depending on the R.PCT calculation and how much additional capacity is to be added.
ADD.R = R.PCT * (C.CAP – capacity after adding a cool- ing stage)
For example: If R.PCT = 0.2 and the control would be add- ing 20% cooling capacity by taking the next step up, 0.2 times 20 = 4 F ADD.R.
Next Stage EDT Increase (SUB.R) — This variable repre- sents (if subtracting a stage of cooling) how much the tempera- ture should rise in degrees depending on the R.PCT calculation and how much capacity is to be subtracted.
SUB.R = R.PCT * (C.CAP – capacity after subtracting a cooling stage)
For Example: If R.PCT = 0.2 and the control would be subtracting 30% capacity by taking the next step down, 0.2 times
Rise Per Percent Capacity (R.PCT) — This is a real time cal- culation that represents the amount of degrees of drop/rise across the evaporator coil versus percent of current running capacity.
R.PCT = (MAT – EDT)/C.CAP
Cap Deadband Subtracting (Y.MIN) — This is a control vari- able used for Low Temp Override (L.TMP) and Slow Change Override (SLOW).
Y.MIN = –SUB.R*0.4375
Cap Deadband Adding (Y.PLU) — This is a control variable used for High Temp Override (H.TMP) and Slow Change Override (SLOW).
Y.PLU = –ADD.R*0.4375
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