Typical Effects Of The Lam With A Diesel Engine With Or Without A Lam (U/F Only) - SDMO R33C3 User And Maintenance Manual

LEROY-SOMER
- LAM : action eliminated by cutting the ST5
jumper.
Voltage
ST5 disconnected
U
N
U/f
0.85 U
N
0
ST3
2.3.2 - Gradual voltage return function
During load impacts, the function helps the
genset to return to its rated speed faster
thanks to a gradual increase in voltage ac-
cording to the principle:
- If the speed drops between 46 and 50 Hz,
the rated voltage follows a fast gradient as it
is restored.
- If the speed drops below 46 Hz, since the
engine needs more help, the voltage follows
a slow gradient as it returns to the reference
value.
U
Drop N > 46 Hz
0
Installation and maintenance
Underspeed and LAM
Voltage
P2
LAM
48 or 57.5 Hz
50 or 60 Hz
fC fN
Drop N ≤ 46 Hz
Time
233/242
R438
A.V.R.
2.4 - Typical effects of the LAM with
a diesel engine with or without a
LAM (U/F only)
2.4.1 - Voltage
Transient voltage drop
U
N
0,9
0,8
0
2.4.2 - Frequency
f
N
0,9
0,8
0
2.4.3 - Power
0
3971 en - 2010.11 / f
without LAM
with
LAM
1 s 2 s
Max speed drop
1 s 2 s
Variation in the load
Load shedding due to "LAM"
1 s 2 s
(U/f)
Time
3 s
with
LAM
without
LAM
Time
3 s
LAM
Time
3 s
7