Friedrich 2003 service manual SYSTEM CONTROL PANEL YQ Model Only

Figure 13	L1
System Control Switch
(EQ Models)	B1
MS	L2

H C

LO2

SYSTEM CONTROL PANEL ("YQ" Model Only)

(See Figure 14)

The YQ Model unit uses a six position control switch to regulate the operation of the unit. Function of each position (Clockwise rotation) is as follows:

1."Off" - Turns everything off.

2."Fan Only" - To circulate filtered room air, but no cooling or heating.

3."Hi Cool" - Fan runs continuously, compressor goes on and off to maintain the selected room temperature.

4."Lo Cool" - Fan runs continuously, compressor goes on and off to maintain the selected room temperature.

5."Lo Heat" - Fan Runs continuously, heating turns on and off to maintain the selected room temperature.

6."Hi Heat" - Fan Runs continuously, heating turns on and off to maintain the selected room temperature.

Figure 14

System Control Panel (YQ Model Only)

SYSTEM CONTROL SWITCH - TEST (See Figure 15) Turn knob to phase of switch to be tested. There must be continuity as follows:

1."Fan Only" Position - between terminals "C" and "1".

2."Hi Cool" Position - between terminals "C" and "1", "C" and "3".

3."Lo Cool" Position - between terminals "C" and "2", and "C" and "3".

4."Lo Heat" Position - between terminals "C" and "2", and "C" and "4".

5."Hi Heat" Position - between terminals "C" and "1", and "C" and "4".

ROTARY (SYSTEM) SWITCH: "SC" Model (See Figure 16) A rotary four position switch is used to turn on the unit and select the operation desired. Switch selection is as follows:

Figure 15

System Control Switch

(YQ Model Only)

Figure 16

System Control Panel (SC Model Only)

1."Hi Cool" Turns on the compressor and fan at high speed

2."Lo Cool" Turns on the compressor and fan at low speed.

3."Fan Only" Turns on the fan at high speed.

4."Off" Turns everything off.

The switching arrangement of the control is as follows: (See Figure 17)

1."Off" All contacts open.

2."Hi Fan Contacts closed between terminals "L1" and "1".

3."Hi Cool" Contacts closed between terminals "L1" to "1" and "L1" and "C".

4."Lo-Cool" Contacts are closed between terminals "L1" to "2" and "L1 to "C".

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