Troubleshooting-Cooling Mode; Diagnostic Display; Instrumentation; Troubleshooting-Heating Mode - Maytag iQ Drive R6GI Installation Instructions Manual

TROUbLESHOOTING - COOLING MODE

Diagnostic Display

The interface board located inside the control panel has a
two character display which provides information regarding
operational status and fault history. When 24VAC control
power is provided to the board, the display will show some
combination of characters. In order to diagnose a problem
with the unit, or to determine its operational status, remove
the control panel cover, then observe the 2-character
lighted display on the interface board. Refer to Table 7.
The display will alternate between an operating code
(Table 17, page 31) and a list of the codes for up to the
last 20 different faults or warnings. When this list is being
displayed, each fault or warning code in memory will
be displayed for 5 seconds. If one of the stored coded
conditions occurs again, no repeat entry will be made. Thus,
the fault codes in the list are not necessarily displayed in
order of occurrence. Fault codes are retained through loss
of power. The fault code list in memory can be cleared by
shorting the J4 Test pins briefly when the compressor is
off. NOTE: This action may also have other consequences
- See Delay Override on page 20.
DISPLAY
CODE
01
Inverter Power Module Overcurrent
02
General Inverter Drive Fault
03
High Compressor Current
04
Current Sampling Error (Inverter)
05
High Inverter Heat Sink Temperature
06
High DC Bus Voltage (Inverter)
07
Low DC Bus Voltage (Inverter)
08
Low Line Voltage at Inverter
09
Line Overcurrent at Inverter
10
Line Voltage Sampling Error (Inverter)
11
Loss of Communication (Inverter Internal)
12
Inverter Heat Sink Sensor Failure
13
Loss of Communication (Inverter Internal)
14
Loss of Communication (IFB to Inverter)
15
Override, High Compressor Current
16
Override, High Line Current
17
Override, High Inverter Heat Sink Temp
18
Outdoor Fan Motor Fault
19
Low Pressure Switch Open
20
High Compressor Discharge Temperature
21
Interface Board Software Error
22
Sensor Failure - Suction Line Temp
23
Sensor Failure - Compressor Dischg Temp
24
Sensor Failure - Ambient Temperature
25
Sensor Failure - Coil Temp #1, Defrost
26
Sensor Failure - Suction Pressure Transdcr
27
Blower Motor Fault
28
Blower Communication Fault
Table 7. Interface Board Diagnostic Codes
24
INDICATION

Instrumentation

The 20 SEER iQ Drive split air conditioner includes
instrumentation as listed in Table 8. All items listed are
connected to the interface board except for the high
pressure switch. Refer to Figures 12 & 13 (page 30), Figure
14 (page 31), Figure 15 (page 32), and Figures 17 & 18
(pages 34 & 35). The five temperature sensors are color
coded so that the color of the wire insulation matches the
color of the connector base on the left side of the circuit
board. All temperature sensors are 10k ohm thermistors.
The resistances of these sensors (when disconnected from
the interface board) may be checked against Figure 23
(page 39) for troubleshooting purposes. The charts show
the thermistor resistance-temperature curve broken into
two parts for ease of use.
FUNCTION TYPE
High Pressure Opens 650 ±15 psig,
Switch recloses 460 ±15 psig
Low Pressure Opens 20 ±5 psig,
Switch recloses 35 ±5 psig
Thermistor 10KΩ @
Ambient
Air Temp 25° C (Fig. 10)
Thermistor 10KΩ @
Compressor
Discharge Temp 25° C (Fig. 10)
Thermistor 10KΩ @
Coil Saturation
Temp 25° C (Fig. 10)
Thermistor 10KΩ @
Suction
Temp 25° C (Fig. 10)
*IFB=Interface Board
Table 8. Instrumentation List
TROUbLESHOOTING - HEATING MODE
If the furnace fails to operate check the following:
• Is the thermostat operating properly?
• Are the blower compartment door(s) in place?
• Is the furnace disconnect closed?
• Has the circuit breaker tripped or the control board fuse
burned open?
• Is the gas turned on?
• Are any manual reset switches open?
• Is the filter dirty or plugged?
• Is the flame sensor coated? (Remove and clean with
steel wool. Do not use emery cloth or sandpaper!)
• Are all the LED's on the furnace and motor control
boards constantly ON? If not, refer to Tables 9 & 10
(page 25) to determine fault condition.
IMPORTANT NOTE: The furnace will lock out after 5
failed attempts for ignition and will try again every
hour if the call for heat remains.
CONNECTION
See Figures 8 & 9
IFB* LP1-LP2
IFB* "OUTDOOR
TEMP" (BLK)
IFB* "DISCHARGE
TEMP" (RED)
IFB* "COIL #2
TEMP" (YEL)
IFB* "SUCTION
TEMP" (BLU)