Technical information

12/01/02

“E” Control Board Functions

An instruction label explaining the “E” board features is in-

cluded somewhere on the unit. You should find it either on

the control box cover, on the inside of the front panel, or

under the top panel. A stick on label is also included with the

service replacement board. If you are replacing an “E” board,

be sure to place the new label over the original label. This

will advise anyone performing future service that the origi-

nal board has been replaced and explain the application

switch as outlined below.

The #2A1410-02 universal replacement board has an appli-

cation switch between relays X3 & X4 that is not included on

the original factory board supplied with the unit. This applica-

tion switch allows this replacement board to be used on older

C and Alpine control board models. The application switch

has 2 positions (C & ALP). On R-404A models, this switch

must be in the ALP position. If the switch is left in the C

position, the compressor contactor will energize as soon as

power is supplied to the unit whether the power switch is ON

or OFF.

There are 4 green LED’s which light in sequence throughout

the unit operation. It is important to note that the green LED’s

are not numbered consecutively. LED1 is located at the edge

of the board beside the K-2 transformer connection. The num-

bering sequence from the outside edge of the board is 1, 4, 3,

and 2.

The green LED’s are also used for a built-in output test which

can be conducted to diagnose a bad board. The label ex-

plains the output test procedure. The correct lighting sequence

for the output test is as follows. When the control switch is

switched ON with the output test switch S-3 ON, after a 5

second delay, LED2 lights. 5 seconds later LED2 goes out

and LED3 lights. 5 seconds later LED3 goes out and LED4

lights. 5 seconds later LED4 goes out and LED1 lights. 5

seconds later LED1 goes out and LED4 lights to begin the

normal sequence of operation. If the LED’s follow this se-

quence, the board is OK. If any other lighting sequence oc-

curs, the board is bad.

A copy of the “E” board label is included on the next page.

Review the board label thoroughly to understand the “E” board

functions.

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12/20/03

2/20/03