, 
- 
.__  . 
.. 
- 
. 
, 
. 
- 
- 
.~. 
--._ 
---. 
24. 
TROUBLESHOOTING 
24.2 
Troubles 
and 
Check 
Points 
Troubl8 
Wotor  does  not  start. 
Wotor  rotates in the 
>pposite  direction. 
9ctual  motor 
speed 
jiers from  the 
set 
speed  excessively. 
Wotor  acceleration  or 
kceleration 
IS 
not 
smooth. 
Wotor 
speed 
vanes 
bring rotation. 
Wotor  current  is  too 
arge. 
Chock 
point. 
1) 
Check  the  main  circuit. 
Is 
power  supplied? 
(Is 
the  POWER  indicating  lamp 
la?) 
Is 
the  motor  connected  conecty, 
Is 
the  start  signal  inpcd? 
Are  both 
the 
forward  and  reverse  rotation  signals  input? 
- 
Is 
the  frequency  set  signal  zero? 
* 
Is 
the  circuit  across  terminals  AU  and 
SD 
closed 
(ON) 
when 
the 
Is 
the  output 
slop 
signal 
(across  terminals 
MRS 
and 
SD) 
or  the  reset 
2) 
Check  the  mpuf  signals. 
frequency  setting  signal 
is 
in 
the 
range  from 
4 
to 
2OmA? 
signal  (across  terminak  RES  and 
SD) 
ON? 
3) 
Check  the  values  set  for  parameters. 
Is 
the  reverse  rotation  prevention  (Pr.78)  function  set? 
Is 
the  setting 
for 
the  reverse  mode  (Pr.79)  cored? 
Are  the  setting  for  the  bias  and  gain  (Pr.902 
to 
Pr.905)  correct? 
Is 
the  setting  for  the  start  frequency  (Pr.13) larger  than  the  operation 
lrequency? 
Is 
the  frequency  setting  for  the  operation  functions  (mutlipie-speed 
operation,  etc.)  correct? 
Is 
the  setting  for  the  upper 
limil 
frequency  (Pr.1)  zero? 
Is 
the  motor  start  constrained? 
* 
Is 
the  load  too  heavy? 
* 
Has  the  emergency 
stop 
status  been  estableshed  by  pressing  the 
4) 
Check  the  load. 
5) 
Others 
parameter  unit  stop  key? 
(Is 
'E 
V 
disprayed 
7) 
Is 
the  alarm  indicating  lamp 
(ALARM)-Ii? 
Is 
the  phase  sequence 
(U, 
V. 
W)  at 
the 
output 
terminals  correct? 
Are  the  start  sgnals  (forward,  reverse)  connected 
correctly? 
Is 
the  frequency  setting  signal  correct?  (Measure  the  input  signal  level.) 
Are  Ihe  values  set  for  the  following  parameters  correct?  Pr.1  (upper  limit 
frequency),  Pr.38  (frequency  at 
5 
VDC  input),  Pr.39  (frequency  at  20mA 
input),  Pr.902  to  Pr.905  (bias  and  gain) 
wires, 
11 
influenced.) 
Is 
acceleration  or  deceleration  time 
too 
short? 
Is 
the  load  too  heavy? 
Is 
the  stall  prevention  function  activated  due  to  excessivdv  larae  value 
Are  the  input  signal  lines  influenced  by  external  noise? 
(use 
shielded 
set  for  torque  boost? 
Is 
the  load  changing? 
- 
1s 
the  frequency  setting  signal  stable? 
Is 
the  load 
too 
heavy? 
Is 
the  value  set  for  torque  boost  (manual) 
too 
large? 
.- 
- 
105 
-