Mitsubishi Electric PQHY-P72ZLMU-A Service Handbook page 306

[ IX Troubleshooting ]
1. Error Code
7102
Wrong number of connected units
2. Error definition and error detection method
The number of connected indoor units is "0" or exceeds the allowable value.
3. Error source, cause, check method and remedy
Error source
Heat source (1) Number of indoor units connected to the heat
unit source terminal block (TB3) for indoor-heat source
transmission lines exceeds limitations described
below.
Number of units
Total number of indoor units
Number of BC controllers
Number of
Main BC controllers
Number of Sub BC controllers
Total number of LOSSNAY
units (During auto address
start-up only)
Total number of heat source
units
(2) Disconnected transmission line from the heat
source unit or BC controller
(3) Short-circuited transmission line
When (2) and (3) apply, the following display will
appear.
(4) The model selection switch (SW5-7) on the heat
source unit is set to OFF. (Normally set to ON)
(5) Heat source unit address setting error
The heat source units in the same refrigerant cir-
cuit do not have sequential address numbers.
(6) A type-G BC controller is connected to a unit P144
model or above.
HWE15150
Cause
Restriction on the number of units
<PQHY>
1 - 15 : P72 model
1 - 20 : P96 model
1 - 26 : P120 model
1 - 31 : P144 model
1 - 36 : P168 model
1 - 41 : P192 model
2 - 46 : P216 model
2 - 50 : P240 - P360 models
<PQRY>
1 - 18 : P72 model
1 - 24 : P96 model
1 - 30 : P120 model
1 - 36 : P144 model
1 - 42 : P168 model
1 - 48 : P192 model
2 - 50 : P216 - P336 models
(P72 - P120 models only)
0,1 or 2
1 : P72 - P120 models
2 : P144 - P240 models
3 : P264 - P360 models
M-NET remote controller
Nothing appears on the remote controller be-
cause it is not powered.
MA remote controller
"HO" or "PLEASE WAIT" blinks.
1) Check whether the number of units con-
nected to the heat source terminal block
(TB3) for indoor-heat source transmission
lines does not exceed the limitation. (See
(1) and (2) on the left.)
2) Check (2) - (3) on the left.
3) Check whether the transmission line for
the terminal block for centralized control
(TB7) is not connected to the terminal
block for the indoor-heat source transmis-
sion line (TB3).
4) Check the setting for the model selection
switch on the heat source unit (Dipswitch-
es SW5-7 on the heat source unit control
board).
1
0 or 1
0 or 1
- 297 -
Check method and remedy
GB