
B–62075E/04
5. TROUBLESHOOTING
273
WARNING
Maintenance of a CNC unit involves many dangers and,
therefore, must be performed only by a qualified technician.
Confirm the green LED PIL and red LED ALM on the front of power unit.
1) Proceed to item 1 when green LED PIL is turned off.
2) Proceed to item 2 when green LED is lit and red LED AML is turned
off.
3) Check item 3 when red LED ALM is lit.
(1)Fuse F1 or F2 on the power unit front panel is blown.
(a) Input power voltage is too high.
(b)Power unit is faulty.
(2)Input voltage is low
Measure voltage at R and S terminals of connector CPI to confirm
appropriate voltage is supplied.
If it is not normal, check machine side magnetics circuit.
200VAC, –15%, 50/ 60Hz, "1Hz, 1φ
240VAC, +10%, 60Hz, "1Hz, 1φ
(3)Power supply unit is faulty.
Conditions for power on are as follows:
AL
ON
COM
OFF
ON button
OFF button
Contacts of external alarm
is open.
Contacts of power on is
closed.
Contacts of power off is
closed.
Power supply unit
Fig. 5.2 (a)
For details, refer to 2.5.1 Configuration of the Power Supply Unit.
(1)Fuse F3 is blown on the front panel of power unit
Check whether +24V is short–circuited or grounded. (See Fig. 5.2(b)).
Regu
lator
+24V
F3
CP5 CP2
9ICRT/MDI
Unit
5.2
POWER CANNOT BE
TURNED ON
Points
Causes and Remedies
1. LED is turned off
2. Conditions for power on
are not satisfied.
(PIL is lit and ALM is off)
3. LED ALM is lit