7/26/2019 Guide for Capacitor Recharging in Delta AC Motor Drives

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Guide For Capacitor Recharging in Delta AC Motor Drives

1. Recharging

The drive DC link capacitors need to be recharged if the drive has been non-operational for more thanone year. Without recharging, capacitors may be damaged when the drive starts to operate. Therecharging methods are introduced in this instruction. Please make sure the drive has been stocked inclean and dry condition before performing recharge. It was recommended to recharge the capacitorsonce a year.

1.1 How to check the drives age

Check the date of manufacture for the drive from the serial number shown on the drive label. The serialnumber tells the year and the week when the drive was manufactured.

Take VFD007B23A label for example,

1.2 Recharging Time

The intermediate circuit of the drive is kept in its nominal voltage for a period of time will wake up thecapacitors. The recharging time required depends on how long the drive has been stocked(non-operational).See figure 1.

Technical AnnouncementDELTA ELECTRONICS, INC. Industrial AutomationB.U.

Security

Classification

General

Confidential

Top-secretProduct AMD Models All VFDSeriesECN No. N/A

Issue No. 116A-FE-xxx-09B05-G-01-01Publish Division

ApplicationEngineering

Publisher Alan ChouReleased Date 11/05/2009

Receiving Div.

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1.3 Drives stocked for less than 2 years

Supply the power to the drive for a period given in figure 1 (Method 1). The drive wakes up itscapacitors by itself. Power drives up once a year to keep the capacitors in good and operationalcondition.

1.4 Drives stocked for 2 years and over

Use method 2A to recharge capacitors if the drives have been stocked for two or more than two years.

WARNING: Disconnect the mains supply while the reforming circui t is connected.

a) Method 2

Capacitors are recharged by switching in a rectifier and resistor circuit, which is connected to the driveinput. The recharging circuit is shown in figure 2. Circuit components values for difference voltage are

shown in table 1.

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Figure 2. The reforming circuit for method 2.

2. Replacement

The drive intermediate circuit works by several electrolytic capacitors. Capacitor life can be extendedby lowering the ambient temperature.

It is not possible to predict capacitor failure. Capacitor failure is usually caused by input power fusefailure or a fault trip. Contact Delta if capacitor failure is suspected. Replacements of Delta AC motordrive capacitors are available from Delta. Do not use other than Delta specified spare parts.