Service manual

AES Refrigerator GLOSSARY OF TERMS continued

THERMO-ELECTRIC SOLENOID VALVE

This device directly replaces the safety valve assembly

found on the manually controlled refrigerators. When the AES selects LP gas operation,

12V

is sent to the solenoid which opens the internal valve. This allows gas to flow onto the test plug

and burner assemblies. Once flame is lit, DC millivolts, produced by thermocouple, will keep the

valve open. If for any reason the reigniter cannot reestablish flame, the thermocouple will cool

which will stop production of DC millivolts. At this time the solenoid valve will close preventing

LP gas to accumulate at the burner.

THERMOSTAT - Very similar to electric thermostats found on the manually controlled refrigerator

models. This thermostat operates off 12V DC and regulates the inside refrigerator temperature on

all heating modes by making and breaking the heat source circuit to the printed circuit board. If

thermostat is broken (bellows relaxed) on any AES, the refrigerator will not operate on any heat

source.

VENTILATION - One of the three requirements for proper cooling unit operation. The coach vent

system must be able to provide a way to direct the hot air produced by the action of the cooling

unit out away from the installation of the refrigerator. The refrigerator extracts heat (cooling)

from the interior of the refrigerator cabinet and dissipates the heat out through the vent system.

The vent area must be free of dead air pockets surrounding the sides and top of the refrigerator

to achieve proper air flow. The smaller size refrigerators utilize a double side wall vent system.

Where the incoming air is drawn through the lower vent and the heat is dissipated through the

upper vent. The larger size refrigerators use a lower side vent and roof vent to accomplish the

same venting requirements. The size and placement of each of these vents is critical so it is

important to refer to the specific vent requirements outlined in the installation manual when

diagnosing vent systems.

VOLTAGE MONITORING 12V DC

(PCB)

- The printed circuit board has the ability to monitor

incoming battery voltage to the terminal block. On the 1st and 2nd generation series models, if

battery voltage drops to approximately 9.5V DC (on 120V

LP gas modes only) the printed

circuit board will electronically “by-pass” the thermostat circuit causing refrigerator to light on

gas and stay on continuously regardless of thermostat knob setting. This is to insure the customer

will not lose cooling due to voltage drop. When the voltage drop occurs the green L.E.D. will

completely shut off to warn customer of low incoming voltage. Third generation series models

have an even more sophisticated 12V DC monitoring system. These models will not engage the 12V

DC heating element circuit until

13.3V

DC is detected at the terminal block for approximately 40

seconds. If proper voltage (13.3V DC) is not established within 40 seconds the printed circuit

board will select LP gas operation. If the

12V

DC circuit to the heating element is initially

completed but, due to demands of all DC appliances in the R.V., the DC voltage drops to

A-7-6