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8. TROUBLESHOOTING
8-1. Overview
(1) Before engaging in troubleshooting
(a) Applicable models
All Super Modular Multi System (SMMS-e) models.
(Indoor units: MM
∗
-AP
∗∗∗
, Outdoor units: MMY-MAP
∗∗∗
6
∗
)
(b) Tools and measuring devices required
• Screwdrivers (Philips, flat head), spanners, long-nose pliers, nipper, pin to push reset switch, etc.
• Multimeter, thermometer, pressure gauge, etc.
(c) Things to check prior to troubleshooting (behaviors listed below are normal)
CAUTION
The cooling performance may be declining considerably when total operating capacity of cooling indoor units
is less than 4 HP WHILE AMBIENT TEMPERATURE IS BELOW 0°C.
(2) Troubleshooting procedure
When a problem occurs, proceed with troubleshooting in accordance with the procedure shown below.
NOTE
Rather than a product trouble (see the List of Check Codes below), the problem could have been caused by
a microprocessor malfunction attributable to a poor quality of the power source or an external noise. Check
for possible noise sources, and shield the remote controller wiring and signal wires as necessary.
e
s
u
a
c
e
l
b
i
s
s
o
P
r
o
i
v
a
h
e
B
.
O
N
1
A compre
ss
or wo
u
ld not
s
t
a
rt
• Co
u
ld it j
us
t
b
e the 3-min
u
te del
a
y period (3 min
u
te
s
a
fter compre
ss
or
s
h
u
tdown)?
• Co
u
ld it j
us
t
b
e the
a
ir conditioner h
a
ving gone
thermostats
OFF?
• Co
u
ld it j
us
t
b
e the
a
ir conditioner oper
a
ting in f
a
n mode or p
u
t on the timer?
• Co
u
ld it j
us
t
b
e the
s
y
s
tem going thro
u
gh initi
a
l comm
u
nic
a
tion?
2
An indoor f
a
n wo
u
ld not
s
t
a
rt
• Co
u
ld it j
us
t
b
e cold
a
ir di
s
ch
a
rge prevention control, which i
s
p
a
rt of
he
a
ting?
3
An o
u
tdoor f
a
n wo
u
ld not
s
t
a
rt or wo
u
ld
ch
a
nge
s
peed for no re
as
on
• Co
u
ld it j
us
t
b
e cooling oper
a
tion
u
nder low o
u
t
s
ide temper
a
t
u
re
condition
s
?
• Co
u
ld it j
us
t
b
e defro
s
ting oper
a
tion?
4
An indoor f
a
n wo
u
ld not
s
top
• Co
u
ld it j
us
t
b
e the elimin
a
tion of re
s
id
ua
l he
a
t
b
eing performed
as
p
a
rt of
the
a
ir conditioner
s
h
u
tdown proce
ss
a
fter he
a
ting oper
a
tion?
5
The
a
ir conditioner wo
u
ld not re
s
pond to
a
s
t
a
rt/
s
top comm
a
nd from
a
remote controller
• Co
u
ld it j
us
t
b
e the
a
ir conditioner oper
a
tion
u
nder extern
a
l or remote
control?
Problem
Any other
problem
Inve
s
tig
a
te check code
di
s
pl
a
yed on interf
a
ce P.C.
b
o
a
rd
of he
a
der
u
nit
Inve
s
tig
a
te check code
di
s
pl
a
yed on interf
a
ce P.C.
b
o
a
rd of relev
a
nt follower
u
nit
Check
the problem
s
ite or
problem
p
a
rt
"E2
8
"
check code
