Carrier 30XA080-500 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 50

Termination -- The mode will terminate when the timer
expires.
Possible Causes -- This mode is in effect only due to the Min-
utes Off Time timel:
MODE 2 (MD02) -- Second Setpoint in Use
Criteria for Mode -- Tested when the unit is ON. This mode
is active when Cooling Setpoint 2 (Setpoints--cCOOL--€
CSP.2) or Ice Setpoint (Setpoints_COOL_CSP3) is in
use. While in this mode, the Active Setpoint (Run Status
--+VIEW--cSETP) will show the CSP.2 or CSP.3 value.
Action Taken -- The unit will operate to the Cooling Setpoint
2 (CSP.2) or Ice Setpoint (CSP.3).
Termination -- This mode will terminate when the Cooling
Setpoint 2 (CSP.2) or Ice Setpoint (CSP.3) is no longer in use.
Possible Causes -- This mode is in effect only due to pro-
grmnming options.
MODE 3 (MD03) -- Reset in Effect
Criteria for Mode -- Tested when the unit is ON. This mode
is active when Temperature Reset (Configuration--¢RSET--€
CRST) is enabled either by CRST=I (Outside Air Tempera-
ture), CRST=2 (Return Water), CRST=3 (4-20 mA Input), or
CRST=4 (Space Temperature) and is active.
Action Taken -- The Active Setpoint (Run Status--cVIEW
---_S'ETP) will be modified according to the progrmnmed
information and will be displayed as the Control Point (Run
Status --+VIEW _CTPT).
Termination -- This mode will terminate when the Tempera-
ture Reset is not modifying the active leaving water set point,
so SETP is the same as CTPT.
Possible Causes -- This mode is in effect only due to pro-
grmnming options.
MODE 4 (MD04) -- Demand Limit Active
Criteria for Mode -- Tested when the unit is ON. This mode
is active when Demand Limit (Configuration--cRSET--€
DMDC) is enabled either by DMDC=I (Switch), DMDC=2
(4-20 mA Input) or the Night Time Low Sound Capacity Limit
((;bnfiguration _OPTN ---)LS.LT).
Action Taken -- The Active Demand Limit Value (Run
Status--_VIEW--_LIM) will display the current demand limit
according to the progrmnmed information and the unit's capac-
ity will be reduced to the mnount shown or lower
Termination -- This mode will terminate when the Demand
Limit command has been lemoved.
Possible Causes -- This mode is in effect only due to pro-
grmnming options.
MODE 5 (MD05) -- Ramp Ixmding Active
Criteria for Mode -- Tested when the unit is ON. This mode
is active when Ramp Loading (Cot_guration_OPTN
_RLS) is enabled and the following conditions are met:
1. The leaving water temperature is more than 4 ° F (2.2 ° C)
from the Control Point (Run Status-+VIEW_CTPT),
and
2. The rate of change of the leaving water temperature is
gleater than the Cool Ramp Ixmding (Set Points--+
COOL _CRMP).
Action Taken -- The control will limit the percent capacity in-
crease until one of the two conditions in Mode 5 is no longer tree.
Termination -- This mode will terminate once either condi-
tions in Mode 5 is no longer tree.
Possible Causes -- This mode is in effect only due to pro-
grmnming options.
MODE 6 (MD06) -- Cooler Heater Active
Criteria for Mode -- Tested whether the unit is ON or OFF.
This mode is active when the cooler heater is energized, if the
Outdoor Air Temperature (Temperature_UNIT_OAT) is
less than the calculated wdue, (Freeze Setpoint + Cooler Heater
Delta T Setpoint [Configuration_SERV--cHTR] default
- 2° F [1.1° C]) and either the Leaving Water Temperature
(Temperature --+UNIT --+LWT)or the Entering Water Ternper-
ature (Temperature--+UNIT--+EWT) are less than or equ:d to
the Freeze Setpoint + Cooler Heater Delta T Setpoint (HTR).
The Freeze Setpoint is 34 F (1.1 C), for fresh water systems
(Configuration _SERV--)FLUD=I). The Freeze Setpoint is
Brine Freeze Setpoint (Configuration_SERV--_LOSP), for
Medium Temperature Brine systems, ((_bnfiguration ---_SERV
-+FLUD=2).
Action Taken -- The cooler heater will be energized.
Termination -- The cooler heater will be deenergized when
both the Entering Water Temperature (EWT) and Leaving
Water Temperature (LWT) are above the Freeze Setpoint +
Cooler Heater Delta T Setpoint (HTR).
Possible Causes -- This mode will be enabled for fieeze pro-
tection. If the temperatures tu'e not as described above, check
the accuracy of the outside ail; entering and leaving water
thermistors.
MODE 7 (MD07) -- Cooler Pumps Rotation
Criteria for Mode -- Tested whether the unit is ON or OFE
This mode is active when the Cooler Pump Sequence (Configu-
ration _OPTN---)PUMP=2) (2 Pumps Automatic Changeover)
and the Pump Rotation Delta Timer ((_bnfiguration _OPTN
--¢ROZP) has expired.
Action Taken -- The control will switch the operation of the
pumps. The lead pump will be operating normally. The lag
pump will be stmted, becoming the lead, and then the origimd
lead pump will be shut down.
Termination -- This mode will terminate when the pump
operation has been completed.
Possible Causes -- This mode is in effect only due to pro-
gmmming options.
MODE 8 (MD08) -- Pump Periodic Start
Criteria for Mode -- This mode is active when the cooler
pump is started for the Periodic Pump Start configuration
(Configuration Mode --€ OPTN---)PM.PS=YES).
Action Taken -- If the pump has not run that day, a pump will
be started and will run for 2 seconds at 2:00 PM. If the machine
is equipped with dual pumps, Pump no. 1 will mn on even &tys
(such as day 2, 4, 6 of the month). Pump no. 2 will run on odd
days (such as day 1,3, 5 of the month).
Termination -- This mode will terminate when the pump
shuts down.
Possible Causes -- This mode is in effect only due to pro-
gramming options.
MODE 9 (MD09) -- Night Ix_w Noise Active
Criteria for Mode -- This mode is active when the Night
Time Low Noise Option has been configured and the time is
within the configured time. Programming a Night Low Noise
Start Time (Configuration_OPTN--)LS.ST) and a Night
Low Noise End Time (Configuration Mode_OPTN
-+LS.ND) configures the option.
Action Taken -- The control will raise the head pressure set
point to reduce the number of condenser fans on, thereby
reducing file sound of the machine. Additionally, if file Night
Time Ix_w Sound Capacity Limit ((;bnfiguration_OPTN
-¢LS.LT) has been configured, the unit's capacity will be lim-
ited to the programmed level.
Termination -- This mode will terminate once the Night Low
Noise End Time (LS.ND) has been reached.
Possible Causes -- This mode is in effect only due to pro-
gramming options.
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