Specifications

75
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 Appendix 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:
RunStatusMenu—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 26 for information on HVAC
modes. The occupied status, unit temperatures, unit set points,
and stage information can also be shown. See Table 83.
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 PRESSURIZAT IO N
DISABLED UNOCC FREE COOL EVACUATION
SOFTSTOP REQUEST TEMPERING HICOOL SMOKE PURGE
REM SW DISABLE TEMPERING LOCOOL
COMP STUCK ON TEMPERING VENT
TEST LOW HEAT
Run Status → VIEW → OCC — Displays the current occupan-
cy status of the control.
Run Status
→ VIEW → MAT — Displays the current value for
mixed-air temperature. This value is calculated based on
return-air and outside-air temperatures and economizer damper
position.
Run Status
→ VIEW → EDT — Displays the current evapora-
tor 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 hydronic heating coil).
Run Status
→ VIEW → LAT — Displays the current leaving-
air temperature during Vent and Hydronic Heating modes. This
value is read at the supply air thermistor location.
Run Status
→ VIEW → EC.C.P — Displays the current econo-
mizer control point value (a target value for air temperature
leaving the evaporator coil location).
Run Status
→ VIEW → ECN.P — Displays the current actual
economizer position (in percentage open).
Run Status
→ VIEW → CL.C.P — Displays the current cool-
ing control point (a target value for air temperature leaving the
evaporator coil location).
Run Status
→ VIEW → C.CAP — Displays the current
amount of unit cooling capacity (in percent of maximum).
Run Status
→ VIEW → HT.C.P — Displays the current heat-
ing control point, for use with staged gas control option only (a
target value for air temperature leaving the supply duct).
Run Status
→ VIEW → HT.ST — Displays the current number
of heating stages active (for staged gas control option only).
Compare to following point.
Run Status
→ VIEW → H.MAX — 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 84. The
current position, commanded position, and whether the econo-
mizer is active can be displayed. All the disabling conditions
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 85.
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 timeguards 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 (–100 to +100) and is used as the means of add-
ing or subtracting a cooling stage during run time. It is a nor-
malized representation of the relationship between “Sum” and
“Z”. See the SUMZ Cooling Algorithm section on page 37.
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 –30 = –6 F SUB.R.
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
Cap Threshold Subtracting (
Z.MIN) — This parameter is
used in the calculation of SMZ and is calculated as follows:
Z.MIN = Configuration
→ COOL → Z.GN *(–10+(4*
(–SUB.R))) * 0.6
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