Storage; Maintenance; Capacitor Recharge - Honeywell NX series User Manual

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3.2

Storage

If the frequency converter is to be kept in store before use make sure that the ambient conditions are
acceptable:
Storing temperature
Relative humidity
If the converter is to be stored during longer periods power should be connected to the converter once a
year and kept on for at least 2 hours. If the storage time exceeds 12 months the electrolytic DC capacitors
need to be charged with caution. Therefore, such a long storage time is not recommended. If longer
storage time is, however, necessary, follow the instructions in chapter 3.3.1 to recharge the capacitors.
3.3

Maintenance

In normal conditions, NX frequency converters are maintenance-free. However, regular maintenance is
recommended to ensure a trouble-free operation and a long lifetime of the drive. We recommend to follow
the table below for maintenance intervals.
Maintenance interval
Whenever necessary
Regularly
12 months (if unit stored)
6-24 months
(depending on environment)
5-7 years
5-10 years
Table 3-1. Maintenance intervals
3.3.1

Capacitor recharge

After a longer storage time the capacitors need to be recharged in order to avoid capacitor damage.
Possible high leakage current through the capacitors must be limited. The best way to achieve this is to
use a DC-power supply with adjustable current limit.
1) Set the current limit to 300...800mA according to the size of the drive.
2) Then connect the DC-power supply to the B+/B- terminals (DC+ to B+, DC- to B-) of the DC-link or
directly to the capacitor terminals. NX converters with no B+/B- terminals (FR8/FR9) can be powered
connecting the DC-supply between two input phases (L1 and L2).
3) In drives FR8 to FR12: To ensure full recharge of capacitors, remove the fuses of the cooling fan. Ask
your distributor for further instructions if necessary.
4) Then set the DC-voltage to the nominal DC-voltage level of the unit (1.35*Un AC) and supply the
converter for at least 1h.
If DC-voltage is not available and the unit has been stored much longer than 12 months deenergized,
consult the factory before connecting power.
RECEIPT OF DELIVERY
°
–40...+70 C
<95%, no condensation
Maintenance action
• Clean heatsink
• Check tightening torques of terminals
• Recharge capacitors (see chapter 3.3.1)
• Check input and output terminals and control
I/O terminals.
• Clean cooling tunnel.
• Check operation of cooling fan, check for cor-
rosion on terminals, busbars and other surfaces
• Check door filters in case of cabinet installation
• Change cooling fans:
main fan
-
internal IP54 fan
-
cabinet cooling fan/filter
-
• Change DC bus capacitors