Sea Ray

Fault Shutdowns and Error Messages
High-Pressure Shutdown
In the Cool Mode, if head pressure rises above 400-425 PSI (28-30 kg/cm2) (usually caused by loss of cooling water flow, refrigerant gas overcharge or a fouled condenser) the SMX II
The SMX II control contains built-in safeguards designed to
protect your air conditioning system. These are described
below. will attempt three restarts, then shut down the entire system.
Hint
Your system must be equipped with a high-pressure switch and low-pressure switch for the high- and low-pressure shut- down to operate. You should check with your dealer to make sure these important protective devices are installed properly.
Fault Codes
If an operational failure occurs, the display will flash one of the following fault code messages. Fault code displays are cancelled by pressing the Off key.
The display will alternately flash “HI/PS”. This is a sustained shutdown, and even when the pressure lowers after shut- down, the system will remain off until reset by pressing the Off key.
In the Heat Mode, a rise in head pressure above the set limit (usually caused by poor airflow or incorrect charge) will cause the compressor to cycle off for two minutes, allowing the heat in the coil to dissipate. This prepares the system for recycling in the Heat Mode. The compressor will then continue to cycle, based on input from the high-pressure switch, until the cabin temperature reaches setpoint, after which compressor cycling is automatically restored to normal operation.
Low-Pressure Shutdown
When installed, the optional low-pressure switch is moni- tored by the SMX II control. The low-pressure switch opens when the suction pressure drops below 30 PSI (2.11 kg/ cm2), and resets at 45 PSI (3.16 kg/cm2). The low-pressure fault routine operates differently in the Cool and Heat Modes.
Cool Mode:
When the low-pressure switch first opens, the unit will run for two minutes, then shut down for 50 seconds. It will do this four times. If the switch has not closed, the unit will shut
Fault Code
Meaning
Result
LO / AC (or 200V)
Operating voltage remained below 100V for three minutes for 230V system)
Shutdown
HI / PS*
Head pressure above 425 PSI
Shutdown
LO / PS*
Suction Pressure below 30 PSI
Shutdown
PE
Program error in software
Shutdown
* Note: The “PS” in the high-pressure and low-pressure fault warning should not be confused as “P5” on the SMX II LED Data Display.