10.98 Forming
Siemens AG 6SE7087-6KP50
SIMOVERT MASTERDRIVES Operating Instructions 10-1
10 Forming
If a unit has been non-operational for more than one year, the DC link
capacitors have to be newly formed. If this is not carried out, the unit
can be damaged when the line voltage is powered up.
If the unit was started-up within one year after having been
manufactured, the DC link capacitors do not have to be re-formed. The
date of manufacture of the unit can be read from the serial number.
(Example: RFU-J60147512345)
Position Example Meaning
1 to 3 RFU- Place of manufacture
4J
K
L
M
1997
1998
1999
2000
5 1 to 9
O
N
D
January to September
October
November
December
6 to 15 Not relevant for forming
The following applies for the above example:
Manufacture took place in June 1997.
During forming, the DC link of the unit is connected up via a rectifier, a
smoothing capacitor and a resistor.
As a result, the DC link capacitors receive a defined voltage and a
limited current, and the internal conditions necessary for the function of
the DC link capacitors are restored.
Motor
connection
U2/T1
V2/T2
W2/T3
PE2
DC link Inverter
C / L+
D / L-
PE3
AC
R
Forming
3 AC 400 V
Ground connection on
removed unit
Fig. 10-1 Forming circuit
How the serial
number is made up