136
Table 62 — Operating Modes
SERVICE
Service Test —
The controls system allows for the oper-
ation of various components in a Service Test mode. While op-
erating in Service Test mode, outputs can be tested and various
components run to confirm proper operation. While operating
compressors in Service Test mode, the capacity control algo-
rithm and all safeties are active. Confirm airflow in the evapo-
rator before starting the unit in Service Test.
NOTE: Main power must be on for Service Test to function.
The Service Test function should be used to verify proper
operation of condenser fan(s), compressors, minimum load
valve solenoid (if installed), and remote alarm relay. To use the
Service Test mode, the Enable/Off/Remote Contact switch
must be in the OFF position. Use the display keys and Service
Test Mode and Sub-Mode Directory table in Appendix A to
enter the mode and display TEST. Press
twice so that
OFF flashes. Enter the password if required. Use either arrow
key to change the TEST value to the ON position and press
. Place the Enable/Off/Remote Contact switch in the
ENABLE position to begin Service Test. Press
and
the up or down key to enter the OUTS, CMPA or CMPB sub-
mode.
Test the condenser fans, liquid line solenoids and alarm re-
lay by changing the item values from OFF to ON. These dis-
crete outputs are then turned off if there is no keypad activity
for 10 minutes. Use the arrow keys to select the desired per-
centage when testing Motormaster
®
V controller or number of
seconds for the digital unloader solenoid, if equipped. All com-
pressor outputs can be turned on, but the control will limit the
rate by staging one compressor per minute. Minimum load
valve relays/solenoids, if installed, can be tested with the com-
pressors on or off. The relays under the CMPA or CMPB mode
will stay on for 10 minutes if there is no keypad activity. Com-
pressors will stay on until they are turned off by the operator.
The Service Test mode will remain enabled for as long as there
is one or more compressors running. All safeties are monitored
during this test and will turn a compressor, circuit or the ma-
chine off, if required. Any other mode or sub-mode can be ac-
cessed, viewed, or changed during the TEST mode. The
MODE item (
Run Status
o
VIEW
) will display NO as long as
the Service mode is enabled. The TEST sub-mode value must
be changed back to OFF before the unit can be switched to En-
able or Remote Control for normal operation.
MODE
ITEM EXPANSION
DESCRIPTION
SYSTEM EFFECT
D.OIL
Digital Oil Recover Mode
Digital compressor has been running
below standard Maximum A1 Unload
Time (
Configuration
o
UNIT
o
MAX.T
) for
more than 30 minutes. Digital compres-
sor will load to 100% for 30 seconds.
Digital compressor will load completely.
supply air temperature may be lower than
Control Point (
Run Status
o
VIEW
o
CTPT
).
L.OUT
OAT Below Lockout Temp
Ambient temperature is below field config-
urable setting, causing mechanical cool-
ing to be disabled.
Unit is not allowed to start.
MD05
Ramp Load Limited
Prevents rapid staging of compressors at
start-up
May not be able to supply air at the Con-
trol Point (
Run Status
o
VIEW
o
CTPT
)
MD06
Timed Override in Effect
Unit is operating outside of normal occu-
pied time period
Normal capacity control is enabled.
MD09
Slow Change Override
Supply air temperature is close to and
moving toward the Control Point
(Run Status
o
VIEW
o
CTPT
)
Capacity stage changes are prohibited.
Unit may not supply air at the Control
Point
(Run Status
o
VIEW
o
CTPT
)
MD10
Minutes Off Time Active
Unit is prohibited from starting until the
timer has expired
Unit is not allowed to start.
MD14
Temperature Reset
Unit is operating with a modified set point Unit is operating with a modified set point
under normal capacity control.
MD15
Demand Limited
Unit capacity is being limited by a
Demand Limit command
Unit may not be able to deliver the desired
supply air temperature.
MD17
Low Temperature Cooling
Supply Air Temperature is decreasing
faster than 0.5 F (0.3 C) and the differ-
ence between the Supply Air Tempera-
ture and Control Point (
Run
Status
o
VIEW
o
CTPT
) exceeds a calcu-
lated value.
Unit may unload.
MD18
High Temperature Cooling
Supply Air Temperature and and its rate
of change are increasing, and the differ-
ence between the Supply Air Tempera-
ture and Control Point (
Run
Status
o
VIEW
o
CTPT
) exceeds a calcu-
lated value.
Unit will automatically load.
MD21
High SCT Circuit A
Circuit SCT exceeds a calculated limit
No additional stages of capacity will be
added. Unit may unload to lower SCT.
MD22
High SCT Circuit B
MD23
Minimum Comp On Time
Compressor has not completed its mini-
mum run time
Compressor will remain running. Supply
Air Temperature may be lower than Con-
trol Point (
Run Status
o
VIEW
o
CTPT
).
MD25
Low Sound Mode
Not supported
Not Supported
MDTG
Time Guard Active
Prevents rapid cycling of a compressor
May allow the unit to overshoot the set
point or not allow a compressor to start if
required.
ENTER
ENTER
ESCAPE