5285477-UIM-A-1016
16
Johnson Controls Unitary Products
Heat Pump Safety Switch Operation
The unit is equipped with a safety package. The refrigeration system
will be protected against high refrigerant pressure and a loss of charge
switch. If either of these safety switches open, the unit will be shut off
for the 5 minute anti-short cycle time. Once this has expired, a six hour
elapsed run timer begins. If a second opening of a safety switch occurs
during this six hour period, the compressor will be locked out.
Resetting the lockout function is accomplished by:
1.
Removing power from the control's thermostat 1st stage (Y) input for
longer than 2 seconds.
2.
Removing power from “R” for more than 2 seconds.
3.
Shorting the “TEST” pins together for more than 2 seconds while
“Y” is energized.
4.
Shorting the “TEST” pins together for more than 5 seconds while
“Y” is de-energized.
Demand Defrost Fault Code Display
The control provides fault codes using the Status LED display. Table 19
describes the LED displays for fault codes. On the LED display, the
control displays a single fault code only. The control displays the fault
code on the LED display repeatedly with a 2 second off period between
repetitions of the fault code. If multiple fault codes are present at the
same time, the LED displays only the highest priority fault. The other
active faults may be accessed via the LAST ERROR button on the con-
trol board.
Table 19 shows the LED display representation for specified faults. For
instance, a red LED display of 10 flashes indicates a control failure.
When any fault code is present, the control does not display the current
status code for the stage of operation.
Electric Heat Limit Switch Operation
The 6HK single phase heat kits utilize a normally closed line voltage
limit switch and a normally closed fusible link. If the fusible link opens, it
must be replaced with the appropriate OEM part and the cause must be
investigated and corrected.
FIGURE 9:
Blower Control
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Table 18:
Test Pins
Test Pin Shorted
With Y Call
Without Y Call
greater than 2 sec
Bypass ASCD
Show error codes
greater than 5 sec
Forced defrost
Clear error codes
Table 19:
Demand Defrost Fault Codes
Description
STATUS LED
High -pressure switch fault (not in lockout yet)
2 Flashes
System in high-pressure switch lockout (last mode of
operation was normal compressor)
3 Flashes
System in high-pressure switch lockout (last mode of
operation was defrost)
4 Flashes
System in loss of charge switch lockout (last mode of
operation was normal compressor)
5 Flashes
Low Voltage (less than 19.2VAC) preventing further
relay outputs for greater than 2 seconds
6 Flashes
Low Voltage (less than 16VAC) stopped current relay
outputs for greater than 2 seconds
7 Flashes
Liquid Line sensor failure (Open or Shorted)
8 Flashes
Outdoor ambient sensor failure (Open or Shorted)
9 Flashes
Control Failure
10 Flashes
