Transducer Troubleshooting; Forcing Inputs And Outputs; Run Status Menu - Carrier Weathermaster 48P030-100 Controls, Start-Up, Operation, Service, And Troubleshooting

Transducer Troubleshooting

The electronic control uses 2 suction pressure transducers to mea-
sure the suction pressure of circuits A and B. The pressure/voltage
characteristics of these transducers are in shown in Tables 95 and
96. The accuracy of these transducers can be verified by connect-
ing an accurate pressure gauge to the second refrigerant port in the
suction line.

Forcing Inputs and Outputs

Many of the variables may be forced both from the CCN and di-
rectly 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 levels 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 literature 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
 
Temperatures AIR.T RAT
 
Temperatures AIR.T SPT
 
Inputs RSET SP.RS
 
Inputs REL.H OA.RH
 
Inputs AIR.Q OAQ

Run Status Menu

The Run Status menu provides the user with important informa-
tion about the unit. The Run Status table can be used to trouble-
shoot problems and to help determine how and why the unit is op-
erating.
AUTO VIEW OF RUN STATUS
The Auto View of Run Status display table provides the most im-
portant unit information. The HVAC Mode (Run Status

VIEW HVAC) informs the user what HVAC mode the unit is
currently in. Refer to the Modes section on page 44 for informa-
tion on HVAC modes. The occupied status, unit temperatures, unit
set points, and stage information can also be shown. See Table 97.
 
Run Status VIEW HVAC
Displays the current HVAC Mode(s) by name. HVAC Modes in-
clude:
OFF VENT
STARTING UP HIGH COOL
SHUTTING DOWN LOW COOL
DISABLED UNOCC FREE COOL
SOFTSTOP REQUEST TEMPERING HICOOL
REM SW DISABLE TEMPERING LOCOOL
COMP STUCK ON TEMPERING VENT
TEST LOW HEAT
 
Run Status VIEW OCC
Displays the current occupancy 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 evaporator discharge air temperature during
Cooling modes. This value is read at the supply air thermistor lo-
cation (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 Hy-
dronic Heating modes. This value is read at the supply air thermis-
tor location.
Outside Air Temperature 30 minutes
Return Air Temperature 3 minutes
Space Temperature 3 minutes
Static Pressure Reset 30 minutes
Outside Air Relative Humidity 30 minutes
Outside Air Quality 30 minutes
HIGH HEAT
FIRE SHUT DOWN
PRESSURIZATION
EVACUATION
SMOKE PURGE
DEHUMIDIFICATION
RE-HEAT

Run Status VIEW
Displays the current economizer control point value (a target value
for air temperature leaving the evaporator coil location).

Run Status VIEW
Displays the current actual economizer position (in percentage
open).

Run Status VIEW
Displays the current position of actuator no. 2 (in percentage
open).

Run Status VIEW
Displays the current cooling control point (a target value for air
temperature leaving the evaporator coil location).

Run Status VIEW
Displays the current amount of unit cooling capacity (in percent of
maximum). Compare to staging tables in Appendix C.

Run Status VIEW
Displays the current number of requested cooling stages. Compare
to staging tables in Appendix C and to C.CAP above.

Run Status VIEW
Displays the current heating control point, for use with staged gas
or modulating gas control option only (a target value for air tem-
perature leaving the supply duct).

Run Status VIEW
Displays the current number of heating stages active (for staged
gas control option only). Compare to following point.

Run Status VIEW
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 98. The current position, commanded posi-
 
tion, and whether the economizer is active can be displayed. All
the disabling conditions for the economizer and outside air infor-
mation is also displayed.
COOLING INFORMATION
The Cooling Information run status display table provides infor-
mation on the cooling operation and the Humidi-MiZer operation
of the unit. See Table 99.
Current Running Capacity (C.CAP)
This variable represents 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 maximum number of cooling stages the con-
trol 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 adding or subtracting a cooling stage during
run time. It is a normalized representation of the relationship be-
tween "Sum" and "Z". See the SUMZ Cooling Algorithm section
on page 55.
115

EC.C.P

ECN.P

EC2.P

CL.C.P

C.CAP

CL.ST

HT.C.P

HT.ST

H.MAX