Passport II
Environmental Control Unit

The Passport II Environmental Control Unit is a microprocessor based controller designed for the precise monitoring of direct expansion and self contained air conditioning systems in marine environments. The control can also be used with chilled water air handlers and is called AH-Passport in this application. The control operates at 115 or 230 volts, each operable at 50 or 60 cycles.

The entire assembly is grounded and protected against static interference and RF noise. The circuit board is conformably coated to provide high resistance to external damage or corrosion.

A display cable with phone-type modular jacks connects the panel to the circuit board. The optional air sensor cable is connected to the circuit board in the same manner. Non-volatile memory stores all user-selectable parameters indefinitely during operation or any power failure situations.

Internal self-diagnostic programs provide complete electronic checks of all lights, sensors, keys and circuits. Fused circuits and M.O.V.s (metal oxide varistors) provide component and board protection.

The Passport II control meets or exceeds applicable ABYC, U.S. Coast Guard Regulations and CE Directives.

Click Control Box for More Info on Passport II
FEATURES ---------------
User Selectable Functions
  • Automatic humidity control - moisture levels can be controlled when boat is unattended.
  • Cool only, heat only, or automatic mode selection.
  • Temperature displayed in Fahrenheit or Celsius.
  • Multiple fan speed selections - automatic or six manual speeds.
  • Cycle fan with compressor or continuous fan operation.
  • Compressor time delay staging for multiple unit applications.
  • Calibration of fan speed settings and temperature display to maintain precise control. Blank display lights when desired.
  • Controls shaded pole and split capacitor fan motors.
  • Compressor fail-safe protection.
  • De-icing cycle is now programmable Water inlet sensor for individual cabin heating with chill chasers (AH-Passport only).
  • Force open water valves for four hours to bleed system (AH-Passport only).
Design Features
  • Low voltage for optimum safety. .
  • Built in air sensor (optional remote sensor).
  • Universal symbols with tactile switches and embossed power key - international recognition.
  • Cabin temperature is continuously displayed. Lexan face plate available in black or white with cameo graphics.
  • Circuit board and 15 display cable are factory installed in the electrical box on self-contained units.
  • Display panels can be mounted with adhesive strips or screws.
  • Easy connections using phone-type modular jacks which are shielded and grounded.

* For white control, specify ECU-PSPRT-W (Passport II) or AH-PSPRT-W (AH-Passport). For black control, specify ECU-PSPRT-B (Passport II) or AH-PSPRT-B (AH-Passport).
** Maximum loads should not exceed 85% of listed output ratings.
*** Used as heater output in AH-Passport mode.
**** Used as water valve output in AH-Passport mode.
***** Custom cables are to be ordered in 5' increments for remote systems.
Maximum length for display and air sensor cables is 150.
Maximum length for water inlet sensor cable is 100.
Voltage (VAC)
Cycle (Hz)
Phase ()
Circuits **
Compressor Output ***
Heater/R.V. Output ****
Fan Output
Set Point Temperature
Display Temperature
Air Sensor Temperature
Sensor Accuracy
2F at 77F
Dimensions (in/cm)
Display Panel
4.50/11.4 W x 3.88/9.8 H x 0.88/2.2 D
Cut Out
3.38/8.6 W x 2.75/7.0 H
Cables (ft/m)*****
Self Contained
Central Systems
Alternate Air Sensor
Outside Air Sensor - optional
Water Inlet Sensor AH-Passport only
Installation Guidelines for Passport II
Each Passport II Environmental Control Unit comprises a display panel, display cable, and a control circuit board assembled into the air conditioning unit's electrical box. Determine the proper location of all components before proceeding with the installation.

Locate and secure the air conditioning unit in a dry, accessible area with the fasteners provided. Secure remote electrical boxes containing the Passport II circuit board with the fittings provided. The central system condensing unit's electrical box can remain factory-installed on top of the unit. Some electrical boxes contain position-sensitive components and require correct mount positioning.

Allow adequate access for all wiring connections. Wiring and circuit breakers must be sized according to marine design standards. Only stranded tinned copper wire should be used. Make sure all components are properly grounded.

Determine the proper location for the display panel in the cabin area (see installation manual) and cut out the bulkhead for mounting (3.375"W x 2.75"H). Properly route and secure the display cable between the control circuit board and the display panel.

Note: In central system applications, the display cable should be routed with the refrigerant line set from the condensing unit to the evaporator/blower assembly. Leave a few inches of extra cable at

each end for ease of installing or removing components. Do not stretch or pull a cable. Do not use staples to secure any cable.

Plug in the display cable (8-pin connector). Attach the other end of the display cable to the display panel. Secure the panel to the bulkhead with the adhesive strips attached. Screws may be used, if necessary, by carefully drilling or cutting the Lexan face plate in the corners over the pre-molded holes in the display panel bezel.

The optional sensor, when used, must be plugged into the 6-pin socket on the circuit board marked "J2". It must be located and installed properly in the return air stream. When used as an outside air temperature sensor, it must be plugged into socket J3, routed and secured properly to a pre-determined location outside the cabin areas. The sensor should not be located in direct sunlight. Refer to the AH-Passport operations manual for proper programming and air and water sensor locations.

Access to the control circuit board is achieved by removing the screws on the electrical box. Slide the front piece containing the components away from the mounting base. Turning this piece over to any side will expose the circuit board and electrical components. A complete wiring diagram is secured to the inside of the mounting base and/or in the operations manual for reference.

In the interest of product improvement, Marine Air Systems' specifications and design as outlined herein are subject to change without prior notice.

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