SDMO R33C3 User And Maintenance Manual page 239

LEROY-SOMER
Checking the internal protection :
Open switch (D) : the excitation current
should increase to its preset ceiling, remain
at that level for ≥ 10 seconds and then drop
to < 1A.
To reset, switch off the power supply by ope-
ning switch (A).
Note: After setting the excitation ceiling as
described, adjust the voltage again (see
section 2.1.1)
(*) In some countries it is a legal requirement
to have a short-circuit current of 3 I
to offer selective protection.
3.2.3 - Special type of use
WARNING
Excitation circuit E+, E- must not be left
open when the machine is running : AVR
damage will occur.
3.2.3.1 - R438 field weakening (SHUNT)
X2
Z1
X1
Z2
E+
E-
The exciter is switched off by disconnecting
the AVR power supply (1 wire - X1 or X2).
Contact rating 16 A - 250V A.C.
3.2.3.2 - R438 field weakening (AREP/
PMG)
X2
Z1
X1
Z2
E+
E-
Installation and maintenance
R438
A.V.R.
The exciter is switched off by disconnecting
the AVR power supply (1 wire on each auxi-
liary winding) - contact rating 16 A - 250V
A.C.
Connection is identical for resetting the AVR
internal protection.
, so as
n
In case of using the de-excitation, pro-
vide a forced excitation.
3.2.3.3 - R438 field forcing
Applications
Guaranteed voltage build-up
Parallel operation, de-energized
Parallel operation, at standstill
Frequency starting
Sustained voltage on overload
237/242
3971 en -
(400V - 10A)
X2
Z1
X1
Z2
E+
E-
Exciter field
Forced excitation
B Volt
2010.11 / f
Diode
+
-
t
Battery (B Volt)
t
Time
B volts Time t
12 (1A) 1 - 2 s
12 (1A) 1 - 2 s
12 (1A) 5 - 10 s
12 (1A) 5 - 10 s
12 (1A) 5 - 10 s
11