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Specification of high-performance vector convertor
2.7.3 Storage of frequency convertor
After purchasing frequency convertor, users should pay attention to temporary and long-term storage:
1. Put in packaging box of our company as per original package for storage.
2. Long-term storage will lead to deterioration of electrolytic capacitor. Ensure electrifying once for at
least 5 hours within 2 years, and voltage regulator should be used to gradually increase input voltage to rated
value.
2.8 Warranty
Free maintenance only suit to frequency convertor. If any fault or damage under normal use, our company is
liable for maintenance for 18 months (since the date of leaving factory and barcode on machine prevails). If beyond
18 months, rational maintenance fee will be charged. Under below conditions, certain maintenance fee will be
charged within 18 months: device damage caused by violating stipulations in manual; damage caused by fire, flood
and abnormal voltage, etc; damage caused by using frequency convertor for abnormal functions. Related service
fee will be calculated as per unified standard of manufacturer. If any contract, the contract will prevail.
2.9 Model selection guidance of braking parts
Figure 2-7 is guidance data. Users can select different resistance value and power based on actual situation
(but resistance value should not be lower than recommended value in figure, the power can be large). The
selection of braking resistance depends on motor power in actual application system, and it's related to system
inertia, deceleration time, potential energy load, so uses can select based on actual situation. The larger the
system inertia, the shorter the deceleration time and thre frequency the braking will be, so braking resistance
should select large power and little resistance value.
2.9.1 Selection of resistance value
During braking, regenerated energy of motor is almost fully consumed on braking resistance. Formula is
below: U*U/R=Pb
U----braking voltage of stable braking (vary with different systems, generally 700V for 380VAC)
Pb----braking power
2.9.2 Power selection of braking resistance
In theory, power of braking resistance conforms with braking power.
Derating to 70% can be used.
Formula: 0.7*Pr=Pb*D
Pr----power of resistance; D----braking frequency (proportion in whole process during regeneration)
Elevator-----20% ~30%
Uncoil/Coil ----20 ~30%
Centrifuge------50%~60%
Casual braking load----5%
10% in general
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