Summary of Fault Codes and Indicator Codes Q3 and Qht Controls for Direct Expansion Systems
16 L-2516 ENGLISH
SUMMARY OF FAULT CODES AND INDICATOR CODES
INITIAL SYSTEM START UP
1. Open the seacock (seawater inlet valve).
2. Turn on the circuit breaker for the air conditioner. If a pump relay is installed, the breaker for the pump must also be
turned on.
3. Turn the control on.
4. Use the control to set the system for cooling or heating and adjust the set point temperature so the unit will turn on.
Table 5: Fault-Code and Indicator-Code Descriptions and Results
Code Description Result
LO / AC Operating voltage remained below acceptable limit for 3 minutes or more (100V for a
115V system or 200V for a 230V system).
Shutdown
HI / PS Head pressure above maximum preset limit. Indicates pump failure or loss of water
flow.
Shutdown
HP / - - High-pressure switch failed open or circuit wires open. Shutdown
LO / PS Suction pressure below minimum preset limit. Indicates loss of gas, or water too cold
for heating during Heat Mode.
Shutdown
LP / - - Suction pressure below minimum preset limit, failed low-pressure switch or circuit wires
open.
Shutdown
- - (flashing) Display connected to SMXII unit. The two components are not compatible. No Operation
IS / - - or - - Inside temperature sensor failure flashes IS / - - for 3 seconds if MODE button is
pressed. After 3 seconds, display shows constant - -. Cool or Heat Mode may be
selected for emergency operation and display will show a constant - -.
Emergency Operation
Ar / FL Display flashes Ar / FL for 15 seconds every 30 minutes indicating return air filter needs
to be cleaned or replaced. Reset and stop flashing by pressing the FAN, UP, and
DOWN buttons simultaneously.
Continue Operation
LC LC flashes momentarily if a button is pressed indicating the display is locked in current
mode of operation. Enter or exit lock mode by pressing the MODE, UP, and FAN
buttons simultaneously. UL flashes for 3 seconds when exiting lock mode.
Continue Operation
OU or Outside
/ 1st digit / 2nd
2 digits or OU
or Outside / - -
Displays the optional outside temperature as OU (Q3) or Outside (Qht) then the first
digit followed by second two digits. Displays OU or Outside / - - if optional outside
temperature sensor is not installed or failed open or shorted. See “Button Functions” on
page 6 for instructions.
Continue Operation
LO / SE After 5 minutes of compressor reverse-cycle heat operation, compressor shuts down if
optional seawater sensor is installed and temperature drops below 40°F (4.4°C). If an
optional electric heater is installed, operation switches from compressor reverse-cycle
heat to electric heater until seawater temperature rises above 43°C (6.1°C). Refer to
“24: Seawater Low Limit Adjustment” on page 13.
Shutdown or
Switch to Optional
Electric Heat.
SE or Water /
1st 2 digits
or SE / - -
Displays the optional seawater temperature as SE (Q3) or Water (Qht) then the first
digit followed by second two digits. Displays SE or Water / - - if optional seawater
temperature sensor is not installed or failed open or shorted. See “Button Functions” on
page 6 for instructions.
Continue Operation
HS / 1st 2
digits
or HS / - -
Displays the optional relative humidity as HS / then the first two digits of relative
humidty. Displays HS / - - if optional humidity sensor is not installed or failed open or
shorted. See “Button Functions” on page 6 for instructions
Continue Operation
To Next Page
Loading...
