Component
Inspec-
tion in-
terval
(1)
Service
sched-
ule
(2)
Preventive maintenance actions
Drive Cooling
capacity
1 year
–
Check for blockages or constrictions in the air passages of the cooling channel. The
heat sinks must be free of dust and condensation.
Capacitors, DC
link
1 year
8–15+
years
The expected lifetime of the capacitors is dependent on the loading profile of the ap-
plication and the environmental temperature. For applications with heavy loads in de-
manding environments or high ripple current, replace electrolytic capacitors every 8
years. If within specification of the drive type, replace every 10–15+ years. Only trained
service personnel may perform this action.
Cleaning and
Filters
1 year
–
The interior of the enclosure should be cleaned annually, and more frequently if nec-
essary. The level of dust in the filter or inside the enclosure is an indicator for when the
next cleaning or filter replacement is required.
Fans
1 year
5–10
years
Inspect the condition and operational status of all cooling fans. With the power off, the
fan axis should feel tight, and spinning the fan with a finger, the rotation should be
almost silent and not have abnormal rotation resistance. When in RUN mode, fan vi-
bration, excessive or strange noise is a sign of the bearings wearing, and the fan
should be replaced.
Grounding
1 year
–
The drive system requires a dedicated ground wire connecting the drive, the output
filter, and the motor to the building ground. Check that the ground connections are
tight and free of paint or oxidation. Daisy-chain connections are not allowed. Braided
straps are recommended if applicable.
PCB
1 year
10–12
years
Visually inspect the PCBs for signs of damage or degrading due to aging, corrosive en-
vironments, dust, or environments with high temperatures. Only trained service per-
sonnel may perform the inspection and service action.
Power cables
and wiring
1 year
–
Check for loose connections, aging, insulation condition, and proper torque to the
drive connections. Check for proper rating of fuses and continuity check. Observe if
there are any signs of operation in a demanding environment. For example, discolora-
tion of the fuse housing may be a sign of condensation or high temperatures.
Vibration
1 year
–
Check for abnormal vibration or noise coming from the drive to ensure that the envi-
ronment is stable for electronic components.
Insulator gas-
kets
1 year
10–15
years
Inspect the insulators for signs of degradation due to high temperature and aging. Re-
placement is based on findings or done at the same time as DC capacitor replacement.
Only trained service personnel may perform this action.
Spare Parts
Spare parts
1 year
2 years
Stock spares in their original boxes in a dry and clean environment. Avoid hot storage
areas. Electrolytic capacitors require reforming as stated in the service schedule. The
reforming is performed by trained service personnel. See
.
Exchange units
and units stor-
ed for long pe-
riods before
commissioning
1 year
2 years
Visually inspect for signs of damage, water, high humidity, corrosion, and dust within
the visual field of view without disassembly. The exchange units with mounted elec-
trolytic capacitors require reforming as stated in the service schedule. The reforming is
performed by trained service personnel. See
1
Defined as the time after the commissioning/start-up or the time from the previous inspection.
2
Defined as the time after the commissioning/start-up or the time from the previous service schedule actions.
AQ275638903263en-000601 / DPD00910 | 125
Danfoss A/S © 2022.12
Maintenance
VACON® NXS/NXP Air-cooled
Operating Guide
