Ecumaxx Manual

Table Of Contents

Introduction

System Features

Solid State Fuses

Operator Controls & Display Panel

Power Button

Modes of Operation

Fan Operation

Basic Operation

Program Mode

Entering Program Mode

Restoring Factory Default Settings

Using Program Mode

Exiting Program Mode

Software Identification

Programmable Parameters

Soft Start Ramp Delay

De-Icing

Theory of Operation

ECU-Maxx System Timing

System Timing Diagram

System Inputs and Outputs

Fail-safe And Fault Handling

Fault handling & fail-safe modes

416 Option Board

Typical Application

Specifications

Factory Programming Options F-1 Through F-8

Introduction

The ECU-Maxx (Environmental Control Unit) is a full featured reverse cycle heat pump controller for marine HVAC. The unit consists of one display control head and a remote high voltage system control module. The system has been designed for easy installation and solid state operation. The following pages describe both operation and user-defined parameters available on the ECU-Maxx.

System Features

AC Voltmeter

The ECU-Maxx's hardware includes an AC voltmeter which is used to monitor and display line voltage. These readings represent the voltage at the control module, not at the electrical panel. The line voltage feature is the first item accessed in the View Mode.

AC Amp Meter

The ECU-Maxx's hardware includes an AC Amp meter to monitor power consumption. Sudden changes in power requirements (current) usually indicate problems with the system. For instance, increased current draw can mean a loss of cooling water, compressor or electrical problems. The system amperage is the second item accessed in View Mode.

Dual Voltage Capability

Line voltage is recognized on power-up by the ECU-Maxx and the unit automatically adapts to the voltage applied. This feature eliminates the need to stock two separate voltage controls.

WARNING! Dual voltage only applies to the control unit itself, not to the equipment it is connected with. The system or cooling assembly must match the line voltage supplied.

Start Capacitor Relay

The ECU-Maxx provides circuitry to simplify the connection of the compressor start capacitor to the system. This feature eliminates the complicated wire harness and relay associated with conventional start capacitor and relay circuits.

Face Plate Air Sensor

The ambient air temperature sensor is located in the display panel. This face plate air sensor produces the best results in most installations; however, the display must be located on an inside wall at eye level.

NOTE: The display should not be subjected to direct sunlight. The alternate (remote) air sensor should be used if these conditions cannot be met.

Ambient Light Sensor

The display panel is equipped with an ambient light sensor (photodiode) which automatically controls the display brightness. This feature allows maximum visibility in very bright conditions while maintaining adequate but subdued brightness in the dark.

Non-Volatile EEPROMMemory

Operating and programmed parameters are entered into nonvolatile memory. If power is lost for any reason, all settings and parameters are retained indefinitely, with no battery or electrical power required. When AC power is restored, the ECU-Maxx will resume operation exactly where it left off, even if it is years later.

Fan Speed Compensation

When AC line voltage falls, the lower fan speeds are gradually increased to prevent fan motor stalling. This option helps maintain constant fan speeds during low dock voltage conditions.

Power Failure Recovery

The ECU-Maxx features automatic shutdown and restart during "brown out" conditions. The system is programmed to shut down after 5 (five) minutes of continuous low line voltage. The unit will automatically restart when the line voltage returns to normal.

Compressor Soft Start

The ECU-Maxx may be configured with an optional Compressor Soft Start feature. The compressor soft start feature has been developed in order to reduce the starting load placed on the electrical system by the compressor. This option is installed at the factory and must be ordered specifically.

Solid State Fuses

The ECU-Maxx monitors the system current before and during any electrical component used to protect all systems from shorts or excessive loading. The solid state fuse system is capable of automatic recovery from electrical problems. This eliminates the need to manually replace fuses. The circuitry also protects the components from problems relating to high current, such as: a locked rotor, loss of cooling water, or other compressor-related problems.

Operator Controls & Display Panel

Please refer to Figure 1, below, for the location of the buttons and displays listed on the following pages:

1. POWER button

The power button is used to switch the ECU-Maxx between Off Mode and On Mode, enter Program Mode and reset the Factory Default Values for the programmable parameters.

2. FAN SPEED button

The fan speed button is used to switch between the automatic and manual fan features and is also used to select the fan speed when in Manual Fan Mode.

3. UP button

The Up button is used to increase the temperature set point value, and to increase the value of programmable parameters when the ECU-Maxx

is in Program Mode.

4. DOWN button

The Down button is used to decrease the temperature set point value, and to decrease the value of programmable parameters when the ECU-Maxx is in Program Mode.

5. MODE button

The Mode button is used to switch between the various modes of operation of the ECU-Maxx. The modes are AUTO, HEAT, COOL and Moisture Control. This button is also used to scroll up through the programmable features in Program Mode.

6. TEMPERATURE SELECT button

The Temperature Select button is used to choose which temperature will be displayed on the 3-digit LED Display. It is also used to enter the View Mode and to scroll down through the programmable features in Program Mode.

7. Three Digit Display

This 3-digit 7-segment LED display is used to display temperature information, program information, voltage, current or fault codes, depending upon the mode selected by the user or the fault detected by the ECU-Maxx. The decimal point to the far right on this display is used to indicate when the compressor is on.

8. HEAT MODE light

The heat mode indicator LED will be lit when Heat Mode has been selected.

9. COOL MODE light

The cool mode indicator LED will be lit when Cool Mode has been selected.

10. AUTOMATIC MODE light

The automatic mode indicator LED will be lit when Auto Mode has been selected. Auto Mode allows for automatic heating and cooling.

11. MOISTURE CONTROL MODE light

The moisture control indicator light will be illuminated when Moisture Control Mode has been selected

12. MANUAL FAN light

The Manual Fan indicator LED will be lit when Manual Fan Mode has been selected.

13. AUTOMATIC FAN light

The Automatic Fan indicator LED will be lit when Automatic Fan Mode has been selected.

14. FAN SPEED INDICATOR BAR GRAPH display

The Fan Speed indicator bar graph is composed of six LEDs. These LEDs are lit in direct proportion to the fan speed, with 1 LED on being Lowest Fan speed and all LEDs on being Highest Fan speed. This display is operational in both Auto and Manual Fan modes.

15. INSIDE AIR TEMPERATURE light

When the Inside Air Temperature indicator LED is lit, the 3-digit display will provide a readout of the inside air temperature as detected by the inside air sensor (located on the face plate unless the alternate air sensor is installed).

16. OUTSIDE AIR TEMPERATURE light

When the Outside Air Temperature indicator LED is lit, the 3-digit display will provide a readout of the outside air temperature as detected by the outside air sensor.

17. SET POINT light

When the Set Point indicator LED is lit, it indicates that the 3-digit display is showing the current temperature set point. This value can be adjusted with the Up and Down buttons.

18. COMPRESSOR ON light

When the last decimal point of the 7-segment LED display is lit, it indicates that the compressor output is active.

Modes of Operation

Off Mode

When the ECU-Maxx is in the Off Mode, all control outputs will be turned off. All programmed parameters and user settings will be saved in nonvolatile memory. Program Mode can only be accessed in the OFF Mode.

On Mode

When the ECU-Maxx is in the On Mode, power will be supplied to the appropriate control outputs, and the displays will indicate the current state of operation. This was the state stored the last time the unit was on.

Note: If the unit is being turned on after an interruption of power, this is considered a power-on reset condition. All lights on the display will flash for one second before normal operation is resumed.

Cool Only Mode

When the ECU-Maxx is configured to be in Cool Only Mode, only the cooling system will be used as needed.

Heat Only Mode

When the ECU-Maxx is configured to be in the Heat Only Mode, only the heating system will be activated as necessary.

Automatic Mode

When the ECU-Maxx is configured to be in the Automatic Mode, both heating and cooling will be supplied as needed. (The HEAT and COOL indicator LEDs will be lit, showing which system is currently in operation.)

Temperature Hysteresis

Temperature is automatically maintained within the programmed temperature range of the set point. For example, the factory default value for the temperature hysteresis is 2: When the temperature requirement has been satisfied, a 2 shift is required to establish demand. A 4 shift is required to change from one mode to the other. Once the required heating or cooling mode has been established, the hysteresis remains 2.

Moisture Control Mode

When the ECU-Maxx is configured for Moisture Control Mode, the system maintains a preset temperature and humidity range. These ranges are programmable.

Fan Operation

Auto Fan Mode

Automatic fan mode allows the ECU-Maxx to determine the fan speed based on ambient room temperature. The closer the temperature is to the set point, the slower the fan speed. This permits a balance between the most efficient temperature control and slower (quieter) fan speeds.

Manual Fan Mode

Manual fan mode allows the customer to set the fan speed manually.

View Mode

View Mode is one of the Service Modes. View mode allows the user to examine system voltage, current, inlet water temperature, total compressor run time, HI and LO Pressure Switch status and the AC line Hz.

Program Mode

Program Mode is one of the Service Modes. Program mode allows the user to change any of the 34 program settings.

To Turn the Unit On

Press the Power Button once. This toggles the ECU-Maxx from Off Mode to On Mode. The panel displays will light, indicating that the unit is ready for operation. If the unit is being turned on after an interruption of power, all lights on the display panel will turn on for 1 second prior to resuming normal operation.

To Turn the Unit Off

Press the Power Button once to toggle the ECU-Maxx from On Mode to Off Mode.

Note: The fan will remain on for 4 (four) minutes after the ECU-Maxx is turned off if heat was being supplied by the Optional CAL Rod Heater.

Selecting Cool Only Mode

Repeatedly press the Mode button until the Cool Mode indicator LED is on, and cooling will be supplied when required.

Selecting Heat Only Mode

Repeatedly press the Mode button until the Heat Mode indicator LED is on, and heating will be supplied when required.

Note: If the water temperature is below the low water limit, the valve and compressor will turn off and heat will be supplied by the optional CAL rod heater, if installed.

Basic Operation

Setting Automatic Mode

Repeatedly pressing the Mode button until the Auto Mode indicator LED is on places the ECU-Maxx in Automatic Mode, and heating or cooling will be supplied as needed. In addition to the Auto mode LED, the Cool and Heat LEDs will be lit when the unit is cooling or heating.

Setting Moisture Control Mode

By repeatedly pressing the Mode button until the Moisture Control indicator is on places the ECU-Maxx in the Moisture Control Mode. Minimum and maximum temperatures as well as humidity levels are controlled in this mode. All parameters are user-programmable.

Adjusting the Set Point

The Set Point should be set to the desired room temperature, as the ECU-Maxx will maintain temperature to within two degrees of the set point. The maximum setting for the set point is 85 F. The minimum setting for the set point is 60 F.

To change the Set Point:

Pressing the Up or Down buttons when the ECU-Maxx is in the On Mode forces the display to show the set point (the Set Point indicator LED will be lit) and will raise or lower the set point. The speed at which the set point changes increases with the time the button is held down. The numbers change slowly at first, then rapidly increase as the button remains depressed. When the up or down button is released, the display will return to its previous state.

Fan Operation

The Fan Control maintains 6 (six) fan speeds, which are indicated by the Fan Speed Bar Graph on the control panel. The fan speeds are equally divided with 1 LED lit being Low Fan and 6 LEDs lit being High Fan.

When the ECU-Maxx is placed in Automatic Fan Mode, the fan speeds will vary according to the difference between room temperature and set point. The farther room temperature is from the set point, the faster the fan will run. As the set point is approached, the fan speeds are reduced, culminating in low fan speed at the set point. A 6 spread between set point and room temperature produces high fan speed. The fan speed is reduced one number for every 1 reduction in

temperature differential. This speed reduction does not take place until the temperature differential between the ambient temperature and the set point is less than 6 (six degrees).

The maximum temperature differential may be increased from 6 to 12 by changing the programmable parameter Automatic Fan Speed Spread. The increase in the spread from 6 to 12 results in one fan speed reduction for every 2 decrease in temperature. When programmed in this mode, high fan speed is used only in extremely hot conditions. Once the room is cooled down, conditions requiring high fan speed are less likely to recur.

Setting Automatic Fan Mode

To place the fan in Automatic Mode, press and release the Fan Speed button until the Auto indicator LED is turned on.

Setting Manual Fan Mode

To place the fan in Manual Mode, press and release the Fan Speed button. This toggles the fan control from Automatic to Manual modes. Pressing and holding the Fan Speed button will cause the fan speed lights to scroll 1 (one) through 6 (six) and then back to 1. Releasing the Fan Speed button when one of these fan speed lights are on will set the fan speed to that number.

Example: Releasing the button when the third LED is on will set a Manual fan speed of 3 or medium.

Note: Selecting 1 through 6 results in a manual fan speed setting and lights the manual lamp. The fan speed will not vary from this setting but will be corrected for low line voltage.

Setting Fan Only Mode

With the ECU-Maxx in OFF Mode, press and release the Fan Speed button to turn the fan on. Press and hold the Fan Speed Button to set the desired fan speed as indicated on the Fan Speed Bar Graph. The ECU-Maxx will enter Fan Only or Circulation Mode. Only the Fan Speed Bar Graph is illuminated during Circulation Mode. Pressing the Fan Button cancels the Fan Only Mode and returns the unit to the OFF Mode.

Note: Automatic fan speeds are not available in Fan Only Mode. Manual fan speeds selected pertain to the Fan Only Mode and do not affect the pre-selected fan speeds in Heat, Cool or Auto Modes.

Entering View Mode

Press and hold the Temp Select button for 2 (two) seconds, then release the button. Use the Up and Down buttons to scroll through the various items that may be viewed. A mnemonic code for the value being displayed is flashed along with the value in view mode. The following items are available for display in View Mode:

1. AC Line Voltage (Voltmeter) (code "AC")

2. AC Amperage (Ammeter) (code "cur")

3. Water Sensor (code "H2O")
4. Total Compressor Run Time (in hours) (code "crt")
5. Freon Low Pressure (code "L-P")
6. Freon High Pressure (code "H-P")
7. AC Line Frequency (50 or 60 Hz) (code "FrE")
Exit View Mode by pressing the Temp Select Button. This will return the unit to normal operation. The ECU-Maxx will exit View Mode automatically if no buttons are pressed for 1 (one) minute.

Program Mode

Program Mode is a mode in which many of the operating parameters may be adjusted. The ECU-Maxx is shipped with Factory Default settings of these programmable parameters (see Factory Default Settings section) which are stored in permanent memory, and can be recalled at any time.

Note: Severe electrical disturbances can sometimes upset the ECU-Maxx's operating sequences. Operator confusion related to program parameters can also cause what seem to be operational problems.

Whenever there is any doubt as to the proper operation of the ECU-Maxx control unit, factory default parameters should be initialized.

Entering Program Mode

Program Mode can only be entered from OFF Mode. From Off Mode, press and hold the Power button for 5 (five) seconds until a "P" appears in the display. Release the Power button and the characters "P-1" followed by a parameter value will appear in the display. The ECU-Maxx is now in program mode.

Note: The ECU-Maxx will exit program mode and return to the OFF Mode if no programming is attempted for 1 (one) minute.

Restoring Factory Default Settings

Initialize Factory Default Settings by pressing and holding the Power button for 10 (ten) seconds when the ECU-Maxx is in the OFF Mode.

Five (5) seconds after the button is pressed, "P" appears in the display. At 10 (ten) seconds, the letters "IP" appear, indicating the initialization process has been completed. Releasing the button momentarily displays the Software Version Number (for example "A0.X"). The ECU-Maxx will return to the OFF Mode.

Using Program Mode

The program parameters are displayed by pressing the Mode button or the Temp select button. Program parameters are designated by "P-nn" in the display, where "nn" is a number from 1 to 34. Pressing the Mode button repeatedly will cause the display to scroll up through all the program parameters. Pressing the Temp Select button will cause the display to scroll down through all the program parameters.

The Up and Down buttons are used to select the data or set the desired limits for the parameter being programmed.

Select Option ON or Option OFF using the Up and Down buttons. This method is followed throughout Program Mode; however, special instructions are included in the section Programmable Parameters for individual functions that require them.

Exiting Program Mode

There are two methods to exit program mode. Press the Power button and the ECU-Maxx returns to the OFF Mode. Not pressing any button for 60 (sixty) seconds will cause the control unit to exit Program Mode.

Software Identification

The software version is identified for 1 (one) second prior to the exit from Program Mode. The software number will appear in the display for one second, then the display turns off.

Programmable Parameters

The 34 programmable parameters along with their Factory Default Settings are listed in at the end of this section. The following are definitions and operating theory for all the programmable functions of the ECU-Maxx.

P-1: Moisture Control Mode Dehumidification Level

Moisture Control Mode contains a dehumidification cycle to help prevent mildew and conserve energy.

Example of Dehumidification Level 1:

Every 4 hours, the fan is started and air is circulated for 30 minutes. The

air temperature is sampled and remembered. Cooling is started and will continue until the temperature is lowered 2. Four hours later, the cycle starts over. However, this cycle does not conflict with the minimum or maximum temperature settings.

The Humidity cycle will not start until the maximum or minimum temperature requirements have been satisfied. Dehumidification can be programmed at one of three levels, as shown in Table 2, above. The factory default setting for this function is Level 1 (2).

P-2: Moisture Control Mode High Temp Set Point

This function sets the minimum cooling temperature that will be maintained in Moisture Control Mode. The range for this value is between 95 F and 77 F. The room temperature where the ECU-Maxx display panel is located (unless a remote air Temp. Sensor has been installed) will not be allowed to exceed the temperature selected by this set point. Use the Up and Down buttons to select the temperature. The factory default value of this setting is 85 F.

P-3: Moisture Control Mode Low Temp Set Point

This function sets the maximum heating temperature that will be maintained in Moisture Control Mode. The range for this value is between 50 F and 69 F. The room temperature where the ECU-Maxx display panel is located (unless a remote air temperature sensor has been installed) will not be allowed to go below the temperature selected by this set point. Use the Up and Down buttons to select the temperature. The factory default value of this setting is 55 F.

P-4: Cycle Pump With Compressor

The pump output can be configured in one of two ways:

Off selects continuous operation of the pump when the ECU-Maxx is on.

On selects the function to allow the pump to cycle with the compressor. This setting reduces pump wear by cycling the pump with the heating or cooling demand only (factory default setting). In this mode the pump will continue to run for 2 minutes after the compressor cycles off.

P-5: Temperature Display Units

Program mode F selects degrees Fahrenheit (F).

Program mode C selects degrees Celsius (C).

IMPORTANT! All temperature functions will be based on whatever system (F or C) is selected. F is the factory default setting.
P-6: Temperature Calibration

Use this feature to calibrate the air sensor within a range of 10.

Enter Program Mode and the current calibration offset will be displayed. Use the Up and Down keys to set the desired number.

P-7: Cycle Fan With Compressor

Normally, the fan remains on all the time; however, this option allows the fan to cycle off when the demand for heating or cooling is satisfied.

Off selects continuous operation of the fan (factory default)

On selects cycle fan with compressor. In this mode the fan will shut off 5 to 135 seconds after the compressor, depending on the value for the compressor start delay.

P-8: High Fan Speed Limit

The upper limit of the fan speed can be reduced to tailor the fan output for various motors. The range of values for the high fan speed are 50 through 80 in arbitrary units. The high fan limit is not permitted above 220 VAC to prevent excessive fan noise.

Use the Up and Down buttons to select the fan speed preset. The factory default setting of this function is 70.

P-9: Low Fan Speed Limit

The low fan limit determines the lowest output allowed for Low Fan speed. The range of values for the low fan speed are 25 through 49 in arbitrary units.

Use the Up and Down buttons to select the fan speed preset. The factory default value of this function is 40.

P10: Fan Motor Select

The fan motor select option provides separate low line voltage corrections for two basic types of motors used in most systems. This option does not select the fan speed tables for fan speeds 1-6. High and low fan speed limits must be adjusted for each fan.

SP selects the shaded pole fan option (factory default)

SC selects the split capacitor type fan.

P11: Automatic Fan Speed Spread

Automatic fan speeds are directly related to temperature reduction in cooling and temperature increases in heating. There are two options available: 1 spread per fan speed or 2 spread per fan speed. In cooling, the fan speeds increase as the temperature exceeds the set point. In heating, the fan speed increases as the temperature decreases in relation to the set point. In both cases, the fan speed increases as the temperature differential between set point and room temperature increases.

1 programs 1 per fan speed. This will bring the fan up to high speed when the set point is 6 from the room temperature. This is the factory default setting.

2 programs 2 spread per fan speed. High fan will be generated at an 12 difference between set point and actual temperature.

Note: High fan speed is not likely to recur after the set point has been reached on initial start-up in mode 2 . This option is provided to help reduce overall system noise by minimizing operation at or near high fan speed.

P12: Automatic Fan Speed Heating Option

Because of the many installation variables, high head pressure can be a problem in the heating mode. To help reduce head pressure, the automatic fan speed operation can be reversed in the heating mode. In other words, the fan speed increases as the set point is approached in heating mode. The fan speed spread option applies to this option.

P13: High Water Limit

The high water limit defines the availability of cooling water for the condenser coil. The water pump and compressor are not allowed to operate above the high water limit. High water temperatures at the condenser inlet usually indicate a lack of cooling water. Temperatures at or above the high water limit are indicated by alternately flashing "H-I" and then "H2O" in the display. Fail-safe protection levels apply to the high water limit.

The range of the high water limit is 100 F to 150 F, with 140F being the factory default value. Use the Up and Down buttons to select the high water limit.

High water limit readings are taken with the compressor running and are compensated for sensor location which is outside the Freon circuit. Since cooling water flows inside the Freon circuit, the settings must be appropriately high.

P14: Low Water Limit

The low water limit defines the availability of heat in the condenser water. Heating can only occur at temperatures above the low water limit. The compressor and water pump are not allowed to operate below the selected low water limit. Temperatures at or below the low water limit are indicated by alternately flashing "L-O" then "H2O" in the display. Fail-safe protection levels apply to the low water limit.

If the optional CAL rod heater is installed, the ECU-Maxx will automatically switch to the CAL rod heater when the water temperature is below the limit. The LO / H2O warning will not be displayed when the CAL rod heater is installed!

The range for the low water limit setting is 40 F through 60 F. 50F is the factory default setting for this function. Use the Up and Down buttons to select the low water limit.

Low water limit readings are taken with the compressor running and are compensated for sensor location which is outside the Freon circuit. Since cooling water flows inside the Freon circuit, the settings must be appropriately low.

P15: Service / Water Sensor Option

The Service / Water Sensor is used to monitor the Water Temperature going through the compressor condenser coils. The Service / Water Sensor jack is located on the 416 Option Board and must be programmed ON if it is installed. P13 and P14 require the Service / Water Sensor be installed!

P16: High Pressure Switch Option

The circuit board is equipped with a pair of Fastons for a high-pressure Freon switch. This software option can be turned off when the switch is not used or for trouble shooting purposes.

P17: Low Pressure Switch Option

A pair of Fastons are supplied for an optional low Freon pressure switch. This software option can be turned off when the switch is not used or for trouble shooting purposes.

P18: High Pressure Freon Switch Disable

This option has been provided to disable High Pressure Faults in heating mode only, since high head pressure can be an acceptable occurrence while heating. This function is only valid if P16 is enabled.

P19: Low Pressure Freon Switch Hold-Off Delay

Low Freon pressure conditions can occur during normal operation. To prevent erroneous LP faults from occurring a hold-off delay is provided. A low Freon pressure event that lasts longer than the delay time will cause a Low Pressure fault to occur.

The minimum delay is 60 seconds. The delay range is 1 to 15 minutes, in 1 minute increments. Use the Up and Down buttons to program the desired hold-off delay. The factory default setting is ten [ 10 ] minutes.

P20: CAL Rod Heater Option

Optional output is provided for an electric strip heater which is placed in the blower housing. This strip heater is referred to as a CAL rod heater. This software option is provided to turn the output on when the heater is installed.

P21: Compressor Start Delay

The compressor start delay is included for use in installations where more than one system is being operated from the same power source. The start delay can be set at different intervals for each control to allow only one compressor to start at a time. The units should be staged at least 5 seconds apart.

The minimum delay is 5 seconds. The maximum delay is 135 seconds. Use the Up and Down buttons to set the delay.

P22: Low Voltage Threshold

The Low Voltage Threshold defines the voltage where the compressor is turned off. The fault code "L-O" then "A-C" will flash alternately with the line voltage in the display.

This function allows the ECU-Maxx to be used on a wide variety of line voltages. The allowable low voltage threshold range is 75 VAC through 100 VAC for 115 Volt units, and 175 VAC through 200 VAC for 220 Volt units. Use the Up and Down buttons to select the low voltage threshold. The voltage will appear in the display and represents the actual line voltage.

P23: Sustained Low Voltage Shut Down

OFF - A continued low line voltage condition for 15 seconds will cause the compressor to turn off while the fault code "LO-AC" alternately flashes with the line voltage in the display. After 4 successive failures, the system requires a manual restart. (See Fail-safe Chart for each level action)

ON - A continued low line voltage condition for 5 minutes will cause the compressor to turn off while the fault code "LO-AC" flashes with the line voltage in the display. After 4 successive failures the system requires a manual restart. (All Fail-safe Levels)

To restart ECU-Maxx manually, press the Power button to reset the unit to the OFF Mode.

P24: Fail-safe Protection Level

Fail-safe protection is offered at three levels, as enumerated in the table above.

Example: If the ECU-Maxx is in cooling mode and the high water limit is exceeded for more than 10 seconds, the pump and compressor will be shut down to prevent burning the motors out.

Note: Four consecutive shutdown events will lead to a sustained system shutdown. The ECU-Maxx can be reset to the ON Mode by pressing the Power button once.

P25: Temperature Hysteresis

Temperature Hysteresis is defined as the difference allowed between set point and actual room temperature. When this difference is exceeded, the ECU-Maxx will call for heating or cooling as required.

The 4 spread required to switch from automatic heating or cooling is not affected by this option. The 4 spread is provided to prevent the control from oscillating between heating and cooling while in Auto Mode.

The ECU-Maxx can be configured to provide 2, 3, 4, 5 or 6 of hysteresis.

P26: System Current Limit

The ECU-Maxx limits the current supplied to the components attached to it. This parameter sets the maximum current available to the power outputs. The valid range of values is 5 to 40 Amperes. The factory default is 35 Amperes. If the unit is operating at 220 VAC, current limit is half the displayed value.

Soft Start Ramp Delay

The compressor soft start feature is a factory-installed option on the ECU-Maxx, developed to reduce the electrical loading placed on the system when the compressor starts up. If soft start has been installed on your system, the Soft Start Ramp Delay Option will adjust the ramp time from 0 to 5 seconds (see system timing diagram in the System Control algorithm section). The factory default setting is 2 seconds.

Use the Up and Down buttons to adjust this setting.

P28: Self Test

The diagnostic self test is included to help verify proper operation of the ECU-Maxx. Upon entering the Test Mode, the following items are checked in the order shown. During the output checks, "P-28" and "ON" will flash in the display

Select ON to enter Test Mode. The following items are performed in the order below. During the test, "P-28" and "ON" will flash in the display.

1. EEPROM Memory test: Should this test fail, all dashes: "- - -", will be displayed and the test will not continue.

2. Air Sensor Test: The face plate air sensor is tested and the temperature displayed. If the sensor is defective, "AIR" will flash continuously in the display. A good sensor will display the correct ambient temperature.

3. Lamp Test: All LEDs are turned in for 3 seconds and then turned off.

4. Alternate Air Sensor Test: If installed, the alternate air sensor is tested in the same manner as the face plate sensor.

5. Water Inlet Sensor Test: The water inlet temperature sensor is checked and should display the correct water temperature, assuming that it has been properly installed. A failed water sensor test will continuously flash "H2O" in the display.

6. Fan Test: The fan is started and brought up to speed. Each fan speed is tested for 5 seconds.

7. Valve Test: The valve is cycled on for 5 seconds and then turned off.

8. Pump Output Test: The pump is turned on for 5 seconds and then turned off.

9. Compressor Test: The compressor output is turned on for 10 seconds and then turned off.

10. Firmware Version will be displayed and then the display will blank out.

Self test can be cancelled at any time by pressing the Power Button. When the Self test is completed ECU-Maxx will exit to the OFF mode.

P29: Outside Air Option

When this option is turned ON, the Alternate Air input jack is used as an outside air sensor input.

P30: Station ID Number

Used to identify the control's placement when connected with the Lan-Maxx network option.

P31: Winterization System Option

This option is used when there is no sea water available. With this option ON, the sea water pump is disabled and Heat is provided by an Electric Heater ONLY. Provides electric heat in colder climates or when the boat is out of the water.

P32: No Reverse Cycle Heating

This option is for cooling only units without reversing valves. An optional electric heater (CAL Rod Heater) must be installed if heating is required.

De-Icing

This option is designed to periodically deice the evaporator coil when low fan speed has been selected. A two minute De-Icing Cycle is performed each hour the thermostat does not detect reduction in cabin temperature. Once the first cycle is initiated low fan speed is increased by one number to help prevent further icing.

P-34: Outside Air Temperature Sensor Calibration

This feature is used to calibrate the outside air sensor plus or minus 10 degrees Fahrenheit.

Temperature Control Algorithm

Note: Heating mode shown with automatic fan speeds reversed, i.e. P-12 ON fan speed increases as set point is approached.

Theory of Operation

ECU-Maxx System Timing

The following discussion explains the steps the ECU-Maxx control takes at the beginning of a heating or cooling cycle. There are two different start-up protocols: timed start and soft start. Soft start has been developed to reduce the starting load placed on the electrical system by the compressor. It is an optional feature and must be installed by the factory. Timed start does not provide the load limiting features of soft start. System timing diagrams appear on the next page.

Timed Start Timing

The need for heating or cooling is determined by the ECU-Maxx. This determines the Valve logic; for instance, the Valve is energized in heating mode. The ECU-Maxx executes the following timed steps:

1. The Fan turned On with the Power Button.

2. The Pump is turned on 6 seconds before the compressor is started.

3. The Valve is shuttled to release residual head pressure.

4. The Start Capacitor is switched on five seconds later.

5. The compressor is enabled at full voltage.

6. The Start Capacitor is switched off immediately after the compressor rotor is spinning.

The system is now up and running, and will remain running until temperature requirements are met. The system shuts down by first turning off the compressor. The Reversing Valve remains energized until the next cycle if the system was in heating. Two minutes after the compressor turns off, the Pump turns off and the Fan is set to Low Speed.

Soft Start Timing

The soft start feature has been developed to reduce the starting load on the electrical system. Soft start is an optional feature on the ECU-Maxx. The soft start ramp delay is programmable from 0 to 5 seconds. This delay may need adjustment for optimal results with your particular system.

When Soft Start is enabled and the ECU-Maxx senses the need for heating or cooling, the following actions are taken:

1. The Fan speed is reduced to Speed 1.

2. The Pump is enabled when the system calls for heating or cooling.

3. The Valve is shuttled to release residual head pressure.

4. The Start Capacitor is enabled.

5. The Compressor voltage is ramped up to full potential.

6. Once the compressor rotor reaches 75% of rated speed (in other words, the soft start circuit senses the correct drop out voltage), the Start Capacitor is released.

7. Two (2) seconds later, the Fan is set to the correct speed.

The system remains up and running until the temperature requirements are satisfied. The shut down sequence is identical to the timed start shutdown sequence.

System Timing Diagram

System Inputs and Outputs

Internal Sensor Inputs

The ECU-Maxx has four internal sensors:

1. Control Panel Air Temperature Sensor

2. Control Panel Ambient Light Sensor

3. AC Line Voltage

4. System Amperage

External Sensor Inputs

The standard ECU-Maxx has inputs for three external sensors. Please refer to Figure 3 for a graphic representation of where these inputs are.

1. Alternate Air / Outside Air Temperature Sensor

2. High Freon Pressure Input (Optional)

3. Low Freon Pressure Input (Optional)

System Outputs

The fan motor is connected to this output. Varying the output voltage controls fan speeds. The fan can be configured for two different modes of operation:

1. On continuously when the system is on.

2. On when the compressor is running and off when the compressor is not running. Note that the fan shuts off 15 seconds after the compressor during normal heating and cooling. If the CAL Rod Heater is installed, the fan runs for 4 minutes after the heater is turned off. The fan also has a 4 minute shut-off delay in moisture control mode.

This output can be configured for two different modes of operation:

1. On continuously when the system is on and the fan is operating.

2. On when the compressor is on and off when the compressor is off. This setting reduces pump wear. The pump will cycle off 2 minutes after the compressor in this mode.

The valve output is turned on when the control senses the need for heating. The water temperature must be greater than the low water limit to activate the valve, if the optional CAL rod heater has been installed.

The compressor output is on when the ECU-Maxx is calling for heating or cooling. The compressor is not on in the heating mode if heat is being supplied by the optional electric CAL rod heater.

The heater output is on when heat is called for and the water temperature is equal to or less than the low water limit, and the heater is installed. Low sea water temperature will cause the unit to switch to the electric heater (if installed). When the heater option is selected, the water inlet option should also be installed.

The compressor start relay is included in the control outputs. The ECU-Maxx monitors compressor starting time and run current to assure proper operation of the relay and efficient compressor start-up. Low line voltage cannot cause the relay to reenergize accidentally as happens with conventional start relays. A start relay malfunction will cause compressor shut down and lock out to prevent compressor failure.

FAN

PUMP

VALVE

COMP.

HEATER

START

RELAY

ECU-Maxx Inputs and Outputs

Fail-safe And Fault Handling

NOTE: See pages 16 and 25 for more detailed descriptions of fail-safe protection levels.

Fault handling & fail-safe modes

Fail-Safe

There are three levels of fail-safe protection. Level 1 is the lowest. In this level, the sensors are not monitored for faults. In the two other levels, the sensor is monitored for faults. In level 2, if a fault is detected, the fault code is displayed, but no other action is taken. In level 3, the fault is displayed and the compressor is shut down.

Lockout

Lockout occurs if three level 4 faults are detected within a heating/cooling cycle. Lockout causes the system to shut down. Lockout can only be cleared by going to the OFF Mode and back to the ON Mode using the Power Button.

Fault Display

When a fault occurs, a fault code is flashed on the display. The flashing can be removed from the display by pushing and releasing the Power button to reset the control. This resets the control but does not remove the fault!

Electrical Short Faults

When a short is detected on one of the system output terminals, the ECU-Maxx will display the fault code "SHO" followed by another code indicating which output is shorted:

"CO" indicates a Compressor short.

"FA" indicates a Fan short.

"PU" indicates a Pump short.

"rE" indicates a Valve short.

416 Option Board

An Optional Accessory Board may be ordered for the ECU-Maxx [Part Number: 416-X0A]. This board provides inputs for the following features:

Auxiliary Heater (CAL Rod Heater)

Outside Air Sensor

Service / Water Sensor

Typical Application

Specifications

Factory Programming Options F-1 Through F-8

Enter the factory program mode by first entering the programming mode then pressing the power and fan buttons simultaneously. Use the mode button to move forward and the Temp select button to scroll back through the factory program items. Once in the factory mode the following program changes can be made:

F-1: Voltage Calibration

The systems volt meter can be adjusted plus or minus 10 volts AC. Use this item to calibrate the voltmeter.

F-2: Calibrate the Current Meter

The systems current meter can be adjusted plus or minus 10 amps. This item is used to calibrate the systems current meter.

F-3: Compressor Run Time Low Range

The compressor run time can be reset should the compressor have to be replaced. F-3 covers the range 1 through 999 hours run time.

F-4: Compressor Run Time High Range

F-4 is used to reset compressor run times from 999 through 10,000 hours. Ten thousand hours would be displayed 10.0 in the display window.

F-5: Short Circuit Test

The short circuit test is normally Off, however, while the unit is being installed the short circuit test can be turned On. Once the system is installed and no short circuits are detected the Short Circuit Test should be turned Off. Turning off the test will speed the cold boot-up time from the AC power off condition.

F-7: Reserved For Future Use

F-7 is a blank memory location reserved for future use.

F-6: Compressor Load Fault Message (CLF) Normally On

Compressor load fault (CLF) occurs when the KLIXON or high head pressure switch opens causing an interruption of power to the compressor. Typical causes would be loss of cooling water or high Freon head pressure. The CLF can be turned off during trouble shooting sessions but should be turned on for normal operation.

F-8: Start Cap Relay Supervisory Circuit (SCR)

The operation of the systems start capacitor and relay are monitored and the compressor is shut down if either item fails. A sticking or failed start component will cause the compressor to fail. Shutting down the compressor and flashing SCR saves unnecessary compressor burnouts. SCR is normally on and can be temporarily turned off for trouble shooting, however, SCR should be turned on after the problem is resolved.

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Every precaution has been taken in the preparation of this manual to insure its accuracy. However, Micro Air Corporation assumes no responsibility for errors and omissions. Neither is any liability assumed for damages resulting from the use of this product and the information contained herein.