10 Maintenance
10.1 Maintenance Schedule
In normal conditions, VACON
®
NX AC drives are maintenance-free. To make sure that the drive operates correctly and has a long life, we
recommend doing regular maintenance. Refer to the table for maintenance intervals.
Table 18: Maintenance Intervals and Tasks
Maintenance interval
Maintenance task
12 months (if the AC
drive is kept in store)
If the AC drive was in store for much longer than 12 months and the capacitors were not charged,
speak to the factory to get instructions before connecting the power.
6–24 months (The inter-
val is different in different
environments.)
•
Do a check of the tightening torques of the terminals.
•
Clean the heat sink.
•
Do a check of the mains terminal, motor terminal, and the control terminals.
•
Clean the cooling channel.
•
Make sure that the cooling fan operates correctly.
•
Make sure that there is no corrosion on the terminals, the busbars or other surfaces.
•
In case of cabinet installation, do a check of the door filters.
5–7 years
Change the cooling fans:
•
the main fan
•
the internal IP54 (UL Type 12) fan
•
the cabinet cooling fan/filter
5–10 years
Change the DC bus capacitors, if the DC voltage ripple is high.
10.2 Reforming the Capacitors
Context:
After a long storage time, it is necessary to reform the capacitors to prevent damage to the capacitors. To make sure that the possible
high leakage current through the capacitors stays in minimum, use a DC supply with an adjustable current limit.
If the AC drive was in store for much longer than 12 months and the capacitors were not charged, speak to the factory to get
instructions before connecting the power.
Procedure
1.
Set the current limit to 300–800 mA to agree with the size of the drive.
2.
Connect the DC supply to the B+/B terminals (DC+ to B+, DC- to B-) of the DC-link or directly to the capacitor terminals. In the NX
AC drives with no B+/B- terminals (FR8/FR9), connect the DC supply between 2 input phases (L1 and L2).
3.
In drives FR8 to FR11: To make sure that the capacitors are fully charged, remove the fuses of the cooling fan. If necessary, speak to
the factory to get more instructions.
4.
Set the DC voltage to the nominal DC voltage level of the AC drive (1.35*U
n
AC) and give the AC drive power for 1 hour, at
minimum.
Maintenance
Operating guide | VACON® NXS/NXP Air-cooled
DPD00910G
122 | Danfoss A/S ©
2018.06