Danfoss iC7 Series Installation Manual page 18

Installation Guide | iC7 Series Liquid-cooled dU/dt Filter OF7U1/OF7U2
Table 4: Maintenance Schedule for Liquid-cooled Filters
Component Inspection
interval
Proper clearances 1 year
Corrosive environ- 1 year
ments
Filter components
Capacitors 1 year
PCB 1 year
Insulators 1 year
Coolant
Log Commissioning/sta
rtup, or at time of
replacing liquid
coolant
Glycols 1 year
Corrosive inhibitors 1 year
Pre-mixed gly- 1 year
col and inhibitor
coolant
18 | Danfoss Drives Oy © 2024.11
(continued)
Service schedule
(1)
–
–
12–15 years
10–12 years
10–15 years
–
Based on findings
Based on findings
Based on findings
Preventive maintenance actions
(2)
Check that the required external clearances for proper airflow for
cooling are followed according to the type of the drive. For clear-
ances, refer to the local design regulations.
Conductive dust and aggressive gases, such as sulphide, chloride,
and salt mist, can damage the electrical and mechanical compo-
nents. Air filters do not remove airborne corrosive chemicals. Act
based on findings.
The expected life time of the capacitor is determined based on
load and the temperature of the environment. Replace parts ac-
cording to the service schedule. For applications with heavy loads
or demanding environments, replace the capacitors every 12
years. In a typical environment, within the specifications of the fil-
ter, replace every 15 years. Only trained service personnel are al-
lowed to perform this action.
Visually inspect the printed circuit boards for signs of damage or
degrading due to aging, corrosive environments, dust, or envi-
ronments with high temperatures. Only trained service personnel
are allowed to perform the inspection and service action.
Inspect the insulators for signs of degradation due to high tem-
perature and aging. Replacement is based on findings. Only
trained service personnel are allowed to perform this action.
Record the water quality specification values to create a baseline
for future reference before and after adding inhibitor and glycol.
Also record the system pressure, coolant flow rate, temperature
range, and create a baseline for future reference.
Measure and record the level of glycol in the cooling system. The
minimum concentration level is always 75/25% demineralized
water/glycol.
Measure and record the level of corrosive inhibitor (Cortec-
VpCI-649) in the liquid coolant (see specification). Measure the
level of the inhibitor every year. If the inhibitor level is below the
recommended level of 1%, add more inhibitor. Before adding
more inhibitor, practice caution not to exceed the level of elec-
trical conductivity. Use the corrosive inhibitor recommended by
Danfoss.
The pre-mixed coolants contain specific percentages of glycol
and inhibitor for antifreeze and corrosion protection. The advan-
tage of using a pre-mixed coolant is that the chemical composi-
tion is within Danfoss specifications, and there is no need for ana-
lyzing the coolant.
Maintenance
AN447722773363en-000201 / 172K1108B