31
CHART 6 -- INDOOR UNIT COMMUNICATION ERROR SIZE 18K AND 24K
* Make sure wires are connected per connection diagrams i.e. L1 to L1 and L2 to L2. Failing to do that will result in a
communication error.
** There is a 2 to 3 minute window to take measurements before the diagnostic light is on again.
Reset main power and
restart system using remote.
Problem persists?
.
No further action is
required
No
Yes
Measure VDC reading on
outdoor between S and G.
Reading positive? **
Yes
Check the wires and
connections between
Indoor and outdoor units*
No
Fix connection or
replace wiring
Yes
No
Replace outdoor board
Replace indoor board.
Notes:
When unit is operating normally and a DC
voltage reading is taken between the S and
G terminal on the outdoor unit (or indoor
unit) positive and negative readings will
fluctuate between 0 and 24V DC.
If indoor board is bad, only a positive
readings will be registered between
terminals S and G on the outdoor unit. The
reverse will apply if outdoor board is bad
(only negative readings will register).
Above data is obtained by having the red
probe of the meter on the S terminal and
the black probe on the G terminal.
* Make sure wires are connected per connection diagrams i.e. L1 to L1 and L2 to L2. Failing to do that will result in a
communication error.
** There is a 2 to 3 minute window to take measurements before the diagnostic light is on again.
Reset main power and
restart system using remote.
Problem persists?
.
No further action is
required
No
Yes
Measure VDC reading on
outdoor between S and G.
Reading positive? **
Yes
Check the wires and
connections between
Indoor and outdoor units*
No
Fix connection or
replace wiring
Yes
No
Replace outdoor board
Replace indoor board.
Notes:
When unit is operating normally and a DC
voltage reading is taken between the S and
G terminal on the outdoor unit (or indoor
unit) positive and negative readings will
fluctuate between 0 and 24V DC.
If indoor board is bad, only a positive
readings will be registered between
terminals S and G on the outdoor unit. The
reverse will apply if outdoor board is bad
(only negative readings will register).
Above data is obtained by having the red
probe of the meter on the S terminal and
the black probe on the G terminal.
Reset main power and
restart system using remote.
Problem persists?
.
No further action is
required
No
Yes
Measure VDC reading on
outdoor between S and G.
Reading positive? **
Yes
Check the wires and
connections between
Indoor and outdoor units*
No
Fix connection or
replace wiring
Yes
No
Replace outdoor board
Replace indoor board.
Notes:
When unit is operating normally and a DC
voltage reading is taken between the S and
G terminal on the outdoor unit (or indoor
unit) positive and negative readings will
fluctuate between 0 and 24V DC.
If indoor board is bad, only a positive
readings will be registered between
terminals S and G on the outdoor unit. The
reverse will apply if outdoor board is bad
(only negative readings will register).
Above data is obtained by having the red
probe of the meter on the S terminal and
the black probe on the G terminal.
A08183
38/40MVC, MVQ