
Generator Control
Basic
T4800 SERIES
Load Sharer for Conventional Governors
Simplified Circuit Diagram
17 18
19 20 21 22 23 24 25 26 27 28 29 30 31 32
REVERSE POWER
T4800
TRIP
(Load Sharer)
WATTINTEST
FREQ.
U
N
1 2 3 4 5 6 7 8 9 10 11 1212131314 15 16
L
1
L
2
L
3
BUS
SYNC. T4500
C/B
I
N
UNLOAD
FREQ.
OUT
GEN
IN
UNLOAD
– –
OUT
FREQ.
SYNC.
PARALLEL
LINES
COM.
IN
+
NEXT
T4800
AUTO
INCR. DECR.
M
Description
The T4800 Load Sharer provides automatic load sharing and
frequency control for parallel running generators. The load
sharing is proportional, meaning that the generators will be
loaded equally compared to their individual capacity.
The load on each generator is compared with the load on
the other generators and corrected until balance is obtained.
Load sharing is necessary after synchronization in order to
reestablish load balance and to obtain long term stability of
load and system frequency (compensating the droop of the
speed governor).
The T4800 has a built-in reverse power protection with
selectable limits and time delays.
Features & Benefits
FEATURES BENEFITS
Adjustable delta frequency,
stability and % load
deviation by front panel
potentiometers
Inputs for disabling internal
frequency control
Reverse power trip
Visual indication of voltage,
increase/decrease and
unload signals
Direct line-line voltage
supply (up to 690 Vac)
Galvanic isolated inputs
DIN rail or screw-mount
Facilitates adjustment during installation and
commissioning. Load deviation adjustment
enables paralleling of differenst size
generators.
Enables operation where system frequency
is set externally such as in grid-parallel
operation
Economic solution for reverse power
protection
Provides quick and concise status
information
Simplifies design and installation–no need for
PTs–or separate power supply
Protects the unit against high AC voltage and
currents from the installation including spikes
Easy installation
Ordering Information
ORDERING
NUMBER
T4800.0010 450 V 400 V 5 A
T4800.0020 230 V 5 A
T4800.0030 480 V 415 V 5 A
T4800.0040 110 V 100 V 1 A
T4800.0050 450 V 400 V 1 A
T4800.0060 127 V 120 V 5 A
T4800.0070 110 V 100 V 5 A
Other supply voltages, nominal currents and combinations are available on request .
© 2013 Littelfuse Protection Relays & Controls
www.littelfuse.com/t4800
TERMINALS
1-1 1-3
Specifications
I
N
Max. Voltage 660 V
Voltage Range 70 -110%
Consumption Voltage 4 VA at U
Continuous Current 2 x I
Frequency Range 35 -70 Hz
N
; Current 0.4 VA at UN;
N
Frequency Adjustment 48-62 Hz
Proportional Band ±50 - 250% load; ±5 - 25% frequency
Dead Band Zone ±2 - 10% load; ±0.2 - 1.0% frequency
Contact rating AC: 400 V, 2 A, 250 VA
DC: 110 V, 2 A, 100 W
Operating Temperature –20°C to +70°C
Vibration Test 4 g RMS according to IEC 60068-2-64
EMC CE according to EN50081-1, EN50082-1,
EN50081-2, EN50082-2, EN61000-6-2:1999
Approvals Certified by major marine classification societies
Burn-in 50 hours before final test
Enclosure Material Polycarbonate, flame retardant
Weight 0.7 kg
Dimensions H 70 mm (2.7“); W 150 mm (5.9“);
D 115 mm (4.5“)
Installation 35 mm DIN rail or 4 mm (
3
/16”) screws
Rev: 4-A-050313