Littelfuse T4400 Series - Manual

T4400 Load Sharer
• Automatic load sharing with voltage
based speed control
• Adaptable to most speed controllers
• 2-wire communication with other
T4400 Load Sharers
• Built-in frequency control
• Load / unload facility with ramp
function
• Reverse power and unloaded trip
• Visual indication of voltage, generator
C/B state and unload signal
• Cost effective and highly reliable
compact design
• 50 hours burn-in before final test
• Operating temperature range:
-20°C to +70°C
• Flame retardant enclosure
• DIN rail or screw mounting
Application
The T4400 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 equal-
ly compared to their individual capacity.
The T4400 works in connection with
most electronic speed controllers.
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 re-establish
load balance and to obtain long term
stability of load and system frequency.
When applied with the B9300 Power
Reference Unit, one or several generators
can be operated in parallel with the grid
(utility).
Together with the T4000 Auto Synchro-
nizer, the T4400 provides the optimal
solution for generator control, both in
land and marine-based applications.
The T4900 VAr-Load Sharer can be used
as a supplement. The combination of
the T4400 and the T4900 will provide
complete load sharing of both active
load and reactive load.
Function
The input to the T4400 is the voltage
and current, from which the active load
and frequency are determined.
The T4400 calculates I x cos f, represen-
ting the active load. The load on each
generator is compared with the load on
the other generators and calculated into
a control signal that is connected to the
electronic speed controller for regulating
the load with optimal speed and
stability.
The T4400 includes a built-in frequency
control and an integration function.
These two features provide a very high
overall stability and compensate for any
drift within the speed controller.
A soft load / unload function is also
provided. When activated, the T4400
will slowly increase or decrease speed to
transfer load to or from the generator. A
built-in relay can automatically trip the
circuit breaker when the unload
procedure is completed.
The T4400 has a built-in reverse power
protection with selectable limits and
time delays.
Fig. 1 shows how to connect to most
Woodward and Heinzmann speed
controllers. For connection to other
makes please refer to the section
“Interfacing” on the following page.
Fig. 1. Application diagram for T4400 and speed controller with -5V to +5V DC input.
So
ft
lo
ad
or unload
Sync.
T4400
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