G E N E R A T O R S

Exclusively from your Cat® dealer

AUTOMATIC VOLTAGE
REGULATOR – R450
The circuitry of the R450 Automatic Voltage Regulator
(AVR) provides closed loop control of the alternator
output voltage by regulating the exciter field current.
The R450 can be powered by Shunt, AREP or PMG
field excitation systems and is fitted as standard
on:
– 5000 Series Alternators
– 6100 Series Alternators
– 7000 Series Alternators
– 8200 Series Alternators

SPECIFICATION: UNDER FREQUENCY LOAD ADJUSTMENT

● Steady state voltage regulation ± 0.5% OPTIONS
● LAM Off: Below a preset knee frequency,
● Short circuit capability: the voltage is reduced at a rate
of 1:1 Volts/Hz
– 3 x Irated for 10 seconds (AREP or PMG
excitation) ● LAM Mode 1: Below a preset knee frequency,
the voltage is reduced at a rate
● Overload protection:
of 2:1 Volts/Hz
– 1.1 x Irated for 90 seconds
● LAM Mode 2: Auto-Adaptive Load Adjustment
● Voltage Sensing: Module

– High Range: 320V < Un < 530V On load impact, the rotation speed of the
generating set decreases. When the speed passes
– Low Range: 80V < Un < 320V below a preset frequency threshold, Adaptive LAM
causes the voltage to decrease by a percentage
● Response Time:
relative to the size of load step applied in order
– Normal (1 sec) for ± 20% voltage variation, to temporarily reduce the amount of active load
or on the engine. Selecting this option will provide
optimum voltage and frequency performance for
– Rapid (0.3 sec) for ± 20% voltage variation load steps greater than 70% of the generating set
rating.
● Remote voltage adjustment range of ± 5%

LEHF00000-00 (08/10)
LEHF0145-00 (09-10)
G E N E R A T O R S
Exclusively from your Cat® dealer

ADJUSTMENT CAPABILITY:
The R450 AVR features the following adjustment ● 50 Hz or 60 Hz frequency selection option
capabilities (please note that no adjustments ● Remote voltage adjustment option
should be made prior to careful consideration of the
alternator installation and maintenance manual): ● Alternator frame selection
● Quadrature droop adjustment Two versions of the R450 AVR are available
● AVR Voltage adjustment depending on the voltage sensing requirement:
● Stability adjustment 1. R450M – voltage sensing from between two
phases (single-phase sensing)
● LAM Model selection
2. R450T – voltage sensing taken from all three
● Excitation ceiling / Overload protection
phases (three-phase sensing)
adjustment
● Selection of normal or rapid response time and
excitation type

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Materials
Materialsand
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specificationsarearesubject
subject to change
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notice. © 2010 Caterpillar
LEHF0145-00 (09-10)
LEHF000-00 (08/10) CAT, CATERPILLAR,
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