5284792-UIM-D-1017
Johnson Controls Unitary Products
9
CHARGE VERIFICATION MODE
The outdoor display will assist the installer with charging the system.
Through interaction with the Outdoor Display the system will operate at
predetermined nominal speed values. During this operation the system
will monitor pressures and temperatures. When the subcooling is within
the predetermined values set by the OEM, the outdoor display will indi-
cate SYSTEM CHARGE VALIDATED. This mode is only available
when the ID temperature is within 73 to 83°
F and humidity is less than
73% as measured by the Hx
TM
thermostat. Operation will continue but
charge will not be verified.
User Interaction/Operation:
1. Press Menu, press Arrow until Modes is displayed, press Select.
Press Arrow until Charge Verification is displayed, press Select.
2. Press Select while in Charge Verification Mode. The system will
detect the Unit Type and Unit Tonnage. The outdoor display will
update and scroll text, see the example below.
Example:
4-TON AC FOUND * VERIFY CHARGE? * 4-TON AC
FOUND * VERIFY CHARGE?
3. Press Select to verify charge, the outdoor display will update and
scroll text, see the example below.
Example:
VERIFYING CHARGE * PLEASE WAIT * VERIFYING
CHARGE * PLEASE WAIT
(5 minute wait time during initial charge calculation)
4. ADD CHARGE or REMOVE CHARGE will display on the banner
with the appropriate response dependent upon the OEM's predeter-
mined values, user may press Select when the banner displays
ADD CHARGE or REMOVE CHARGE. The display will indicate
ACCEPTED for 5 seconds and return to the example defined in
Step 1. However, if the system does meet the charge requirements
defined by the OEM, the outdoor display will indicate the below text
example for 5 seconds and return to the text example in Step 2 until
charge verification has fully completed.
Example:
SYSTEM CHARGE VALIDATED
The system will repeat steps 1-3 until the subcooling has reached the
predetermined values set by the OEM.
5. Once charge verification is fully complete the outdoor display will
return to the Second Menu Layer.
SECTION VII: SYSTEM OPERATION
SERVICE MODE
Service mode locks the system into maximum capacity operation based
on ambient conditions. The unit will be locked into steady state condi-
tions where operation and performance can be evaluated using the
available service information. This function is outside of the charge ver-
ification mode, available for all system component diagnostics and can
only be access from the outdoor control.
ANTI SHORT-CYCLE DELAY
The control includes a five-minute anti short-cycle delay (ASCD) timer
to prevent the compressor from short-cycling after a power or thermo-
stat signal interruption. The ASCD timer is applied when the control is
first powered and immediately following the completion of a compressor
run cycle. The compressor and the outdoor fan will not operate during
the five minutes that the timer is active.
LOW VOLTAGE DETECTION
The control monitors the outdoor transformer secondary (24 VAC) volt-
age and provides low voltage protection for the heat pump and its com-
ponents. If the voltage drops below approximately 22 VAC, the control
continues to energize any outputs that are already energized. If the volt-
age drops below approximately 19 VAC, the control immediately de-
energizes the outputs and can no longer energize any outputs until the
voltage level increases above 22VAC. The control stores and displays
the appropriate fault codes when low voltage conditions occur.
TEST MODE OPERATION
Test mode operation provides the features found in Table 3 to assists in
unit commissioning and troubleshooting. TEST MODE is accessed
through the Outdoor Display. Please see Page 11 & Table 6 for detailed
Outdoor Display operation. Test mode can only be accessed from the
outdoor control.
FAULT AND STATUS CODE BEHAVIOR
Fault Code Storage
The main control stores the ten most recent fault codes for review by
the service technician. These codes are stored even when power is
removed from the control and will remain in memory until the control is
powered for 30 consecutive days or manually cleared from the control.
All codes are stored in order of occurrence and time stamped.
The control stores only one identical fault code during the same series
of events. For example, if two or more high pressure switch (HPS) faults
occur sequentially without another fault occurring in between the HPS
faults, the control only stores the HPS fault once.
In addition, the main unit control stores the following unit sensor values
when a fault and/or event occurs.
1. Suction Superheat
2. Liquid Subcooling
3. Liquid Temperature
4. Discharge Pressure
5. Suction Temperature
6. Suction Pressure
When a fault and/or event is present, the system will indicate the corre-
sponding fault and/or event text on the Outdoor Display status banner.
Fault Code Display
The system will provide fault and/or event text, using the Outdoor Dis-
play when CURRENT and/or STORED SYSTEM FAULT(s) are
selected from the FAULT MODE category. Tables 7 & 8 describe the
fault codes in more detail, giving potential causes and troubleshooting
actions. If multiple faults and/or events are present at the same time,
the Outdoor Display will show the most recent fault and/or event with
the highest priority. In the event that multiple faults and/or events are
populated at the same time, the Outdoor Display will indicate the most
recent system fault and/or event that is stored in memory. The second
system fault will not be displayed, but will be stored in memory. For
example see Table 4.
TABLE 3:
TEST Mode Option
TEST MODE OPTION
Menu Options
Operation
OPERATIONAL MODE (AC - HP)
Display current system configuration (AC or HP) and unit capacity stored in memory.
BYPASS ASCD TIMER
Bypass ASCD timer and initiate system operation if a call for space conditioning is present from the HX
TM
thermostat.
NOTICE
The display will continue to indicate the above fault (saved) value(s)
on the Outdoor Display with the active Fault and/or Event text, while
the fault and/or event is still present. When the fault and/or event has
cleared, the system will return to the General Display Operation.
