control box. Though the thermostat has many operational modes, such as operational programming, time of day, etc., all you need to do to operate the basic functions of cool and heat is to put the HEAT-OFF-COOL switch in the applicable position and depress the UP or DOWN ARROW to set the desired temperature.
2. Heating Options:
Mermaid offers two optional types of heating technologies for their units. One option is "electric heat". This option employs electrical heating coils placed in the path of cabin return air. Return air is heated as it passes over the electrical coils and is then forced back into the cabin. The electric heat option is available only on the M-6, M-9 and M-12 Models. The second heat option is a "heat pump". In this option the system freon is forced to flow through the unit evaporator in a reverse direction heating the evaporator. Cabin return air is pulled through the evaporator, heating the air as it passes through, and then forces it back into the cabin. This is the same principal used in many home and pool heating devices and is also referred to as "reverse cycle" heat. The heat pump option is available with all the Mermaid models.
3. Electrical:
a)All Mermaid air conditioner models are available in either 115 vac or 220 vac configurations. Shore power is applied to the air conditioner from the boat’s main circuit breaker through a dedicated air conditioner circuit breaker to the air conditioner electrical box. This power is distributed to various components inside the electrical box including a 115/220 vac to 24 vac reduction transformer. The thermostat utilizes the 24 volts to activate the appropriate relays inside the electrical box which, when energized, apply 115 or 220 vac power to the blower, compressor and water pump. Through a time-delay device inside the electrical box, the power is provided to the pump and blower immediately, followed by the power to the compressor approximately ½ to 1 second later. This device is advantageous for those “limited power supply” situations by lowering the initial starting surge. The blower may be operated independently of the compressor and water pump if only circulating air and not refrigerated air is desired. This is accomplished by simply placing the FAN switch in the FAN ON position. (Mermaid’s FX-1 Controls utilize 110v or 220v operation and time delays are automatic in the programming on the circuit board.)
b)When the HEAT-OFF-COOL switch is placed in the COOL position and the SET temperature is set below cabin ambient temperature, the thermostat will activate both the fan and main contactor relays in the electrical box. When the main contactor relay is activated, 115 vac will be applied to the water pump and fan relay powering the blower, followed by a ½ to 1 second delay providing power to the start and run capacitors as well as the high pressure switch. If the high pressure switch is closed, power will pass through the switch to the compressor safety switch to the "compressor" motor windings. 115 vac power is also applied to the compressor motor "run" and "start" windings from the start and run capacitors. The compressor will now begin to run along with the previously running fan and pump.