PROCEDURE TO PRE-CHARGE THE CAPACITORS IN A
SIMOVERT MASTERDRIVES 6SE70 AC DRIVE
380-480 VAC or 510-650 VDC RATED
2
Why Is This Procedure Necessary?
All AC drives have internal capacitors that maintain the internal DC bus within the drive.
When an AC drive does not have incoming AC or DC power applied to it for long periods
of time, these capacitors slowly discharge. After 1 year has passed, the capacitor
discharging begins dropping to a level that increases the chance of damaging the drive if
full voltage is applied instantaneously. A drive that has been without power for 12
months or less will not experience enough capacitance discharging to be of concern.
However, once this period of inactivity exceeds 1 year, it becomes increasingly
necessary to “form” these capacitors by applying a DC voltage to them that slowly ramps
up from 0 to full voltage. If you have a Siemens SIMOVERT Masterdrives AC drive that
has never been powered up, the period of inactivity would go back to its manufacturing
date. The month and year the drive was manufactured can be determined from the
serial number of the drive. Determining this date is detailed on pages 3-4 of this
document.
Methods of Forming Capacitors
There are two different methods for forming capacitors. One way is to purchase a
Siemens SIMOVERT Regen Rectifier which has the ability to slowly ramp up its DC
voltage output in accordance to the needs of the drive. Since very little current is
required for this forming procedure, the smallest regen rectifier will work for any drive.
The 7.5kW regen rectifier, 6SE7022-1EC85-1AA0, is transportable at 50lbs and offers a
simple procedure of only setting 2 parameters to start the process. Examples of wiring
for the rectifier and drive are shown on page 5 of this document.
The second way to form the capacitors involves a power bridge rectifier, resistor and
capacitor and creating your own power network. Details on the specifications of these
components are shown on page 6 of this document.
MD-6SE70_capacitor_recharge_details.doc12/11/2009
3
DETERMINING A MASTERDRIVE’S MANUFACTURED DATE
MASTERDRIVES Compact & Chassis drives
Serial # example: A-N60147512345 => June 2001
Digit Example
1 and 2
3
4
5 to 14
AN
P
R
S
T
U
V
W
X
A
B
C
D
E
F
1 to 9
O
N
D
Meaning
Place of Manufacturing
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
January to September
October
November
December
Not relevant to date of manufacturing
MD-6SE70_capacitor_recharge_details.doc12/11/2009
4
DETERMINING A MASTERDRIVE’S MANUFACTURED DATE
MASTERDRIVES Compact PLUS drives
Serial # example: F2SD123456 => December 2004
Digit Example
1 and 2
3
4
5 to 10
F2
R
S
T
U
V
W
X
A
B
C
D
E
F
1 to 9
O
N
D
Meaning
Place of Manufacturing
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
January to September
October
November
December
Not relevant to date of manufacturing
MD-6SE70_capacitor_recharge_details.doc12/11/2009
5
CONNECTIONS FOR FORMING CAPS
WITH A REGEN RECTIFIER
MD-6SE70_capacitor_recharge_details.doc12/11/2009
6
STEPS FOR FORMING CAPACITORS WITH REGEN RECTIFIER
WARNING!!! – It is very important that the rectifier and AC drive both belong to the same
voltage class for this procedure. This document is only intended to be used for drives in
the 380-480 VAC voltage class (9th digit of the MLFB part number is ‘E’).
1)
2)
3)
4)
Determine the length of time the AC drive has been without 3 phase AC
power applied
If this time is greater than 1 year, plan to form the capacitors for
approximately 1 hour for each year of inactivity. For example, 3 years without
power would require 3 hours of capacitor forming time
Make sure the AC drive is disconnected from incoming power or a motor and
3ph power is not present on the inputs to the regen rectifier
Using 14 AWG wire or larger, make the wiring connections between the
rectifier and the AC drive as shown on the previous page
NOTE: During the forming procedure, the connected AC drive must not be switch on
5)
6)
7)
8)
9)
Apply 24 VDC power to the rectifier at the X9 terminal strip (+24V at X9-1 and
24V common at X9-2)
Apply 380-480 VAC to the input terminals of the rectifier unit
Using the PMU keypad on the front of the rectifier, set the following
parameters:
P408 = # of minutes for duration of cap forming (approximately 60 minutes for
each year of inactivity)
P554.01 = 1010 ; This allows the 0/1 buttons on the PMU to control the
ON/OFF of the rectifier
P052 = 20 ; This puts the regen rectifier into the special “Form DC Link”
mode
It is necessary to press the “1” button on the PMU within 20 seconds of
setting P052=20. If 20 s is exceeded, the rectifier will fault. If this happens,
clear the fault and reset P052=20 and press “1”
The PMU will display o009 when the procedure is complete
NOTE: The customer is responsible for sizing and providing circuit protection devices
for incoming 3ph AC power
MD-6SE70_capacitor_recharge_details.doc12/11/2009
7
CONNECTIONS FOR FORMING CAPS WITH COMPONENTS
MD-6SE70_capacitor_recharge_details.doc12/11/2009
8
STEPS FOR FORMING CAPACITORS WITH COMPONENTS
WARNING!!! – It is very important that the rectifier and AC drive both belong to the same
voltage class for this procedure. This document is only intended to be used for drives in
the 380-480 VAC voltage class (9th digit of the MLFB part number is ‘E’).
1)
2)
3)
4)
Determine the length of time the AC drive has been without 3 phase AC
power applied
If this time is greater than 1 year, plan to form the capacitors for
approximately 1 hour for each year of inactivity. For example, 3 years without
power would require 3 hours of capacitor forming time
Make sure the AC drive is disconnected from incoming power or a motor and
3ph power is not present on the input terminals of the bridge rectifier
Using 14 AWG wire or larger, make the wiring connections between the
bridge rectifier / resistor and the AC drive as shown on the previous page
NOTE: During the forming procedure, the connected AC drive must not be switch on
5)
6)
7)
Make sure the resistor and capacitor values in your circuit are correct for the
frame size of your connected AC drive (see previous page)
Apply 380-480 VAC to the input terminals of the bridge rectifier unit
Wait for the appropriate amount of time before disconnecting the incoming
power to the bridge rectifier
NOTE: The customer is responsible for sizing and providing circuit protection devices
for incoming 3ph AC power
Possible vendors and part numbers for components
Component
Bridge rectifier; 1600V
Capacitor; 22nF / 1600V
Resistor; 470 Ohm / 100W
Resistor; 330 Ohm / 175W
Resistor; 100 Ohm / 500W
Vendor
Semikron
EPCOS
Ohmite
Ohmite
Ohmite
MD-6SE70_capacitor_recharge_details.doc12/11/2009
Part Number
SKD 62/16
B32653A1223+K
L100J470
L175J330
L500J100
9
EXPLANATION OF MASTERDRIVES PART NUMBER
MD-6SE70_capacitor_recharge_details.doc12/11/2009