Power Drive Systems DUNLITE UVR100 User Manual

James Hamilton Electrical Pty Ltd (Inc in Qld) A.C.N. 010 848 389 trading as

Power Drive Systems

Generator Control Specialists

48A Ainsdale Street Telephone: [phone] P.O. Box 30
West Chermside, Qld 4032 Facsimile: 3350 1654 Grange, Qld 4051
Australia Mobile: [phone] Australia
email: [e-mail] www.powersystems.com.au

DUNLITE UVR100

AUTOMATIC VOLTAGE REGULATOR

POWER DRIVE SYSTEMS

DUNLITE UVR100 AUTOMATIC VOLTAGE REGULATOR

1

GENERAL

This regulator is a solid-state device primarily designed to give precise and stable voltage regulation of an
alternator under adverse operating conditions.

The regulator is suitable for operation on either single or three phase 240/415 or 120/208 volt brushless
alternators.

OPERATION

The regulator senses the output voltage of the alternator and compares this value with a pre-set voltage
reference within its circuitry. The regulator constantly adjusts the field excitation of the alternator to
compensate for variations in load and prime mover speed, and holds the output voltage to within plus or
minus 1.5% no load to full load, unity to 0.8 power factor lagging, and a speed variation of 4.5%.

CONNECTION DETAILS

There are 14 screw terminals on the regulator and their functions are as follows. Early models are labelled
R.W.B in place of U.V.W.

N - Must always be connected to the neutral of the alternator.
U & V - Sensing terminals for voltage regulation.
W - Power terminal for exciter field.
F+ F- - Alternator exciter field terminals.
pp - Terminals for a 5k remote voltage adjustment potentiometer.
D1,D2 - Terminals for the addition of drooping circuit for parallel operation.
S+ S1 - Terminals for remote indication of the SCOOP operation, Series 2000 control (later models only).

THREE PHASE OPERATION

The regulator must be adjusted for either 415 or 208 volts sensing, depending on the available sensing
leads on the alternator. If in doubt, contact Dunlite, stating alternator serial number.

Open the regulator box by unclipping the side catches, and adjacent to the transformer, will be found four
pins connected to various taps of the transformer. The purple fly lead must be connected to the relevant
pin to match the regulator to the available sensing outputs of the alternator.

Starting from the pin nearest the transformer, the sensing voltages are 120V, 208V, 240V, 415V.

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POWER DRIVE SYSTEMS

DUNLITE UVR100 AUTOMATIC VOLTAGE REGULATOR

2

NOTE

When the regulator is fitted within a separate control cubicle, the terminals U, V, W and N will have been
factory connected to AC supply points within the cubicle.

Similarly, the voltage adjustment terminals PP may have been connected to a separate potentiometer ­normally these terminals will be bridged, as will also the droop circuit terminals D1, D2.

The only terminals requiring connection when installing the plant will be the F+ and F- (grey and white
respectively) and a small terminal block is fitted within the alternator terminal box for interconnection
purposes.

Once the above has been completed, the regulator may be connected to the alternator. N to neutral, U to
Red phase, V to White phase, W to Blue phase, F+ and F- to Field. D1 D2 and PP must be bridged if not
connected to external potentiometers ~ see diagram.

Note: Later model UVR100 regulator violet wires to S+ & S (See SCOOP Section)

SINGLE PHASE OPERATION

As for three phase operation, the regulator must be adjusted for either 240 or 120 volt sensing. This can be
done by the purple fly lead as for three phase operation.

For single phase operation, terminals N and U are bridged and connected to neutral, terminals V and W
are bridged and connected to the alternator sensing. The remaining terminals are connected as for three
phase operation. See diagram.

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POWER DRIVE SYSTEMS

DUNLITE UVR100 AUTOMATIC VOLTAGE REGULATOR

3

CONTROLS
There are three standard controls on each regulator. They are -

1. Voltage Adjust

This potentiometer varies the internal voltage reference of the regulator, hence varying the alternator
output voltage over a range of plus or minus 10%. An external 5K potentiometer may be added to terminals
PP for remote voltage adjustment. Under these circumstances RVI, should be fully clockwise.

2. Stability

This potentiometer varies the stability the system and should initially be set in an anti-clockwise position
and rotated clockwise to give optimum stability and response characteristics. Once set it should not be
necessary to carry out further adjustment to this control.

3. SCOOP

All UVR100 regulators incorporate SCOOP (Speed, Current Operated, Overload Protection) as a standard
feature.

If the engine slows down due to either an overload on the alternator or a mechanical fault in the engine, the
exciter field voltage will increase. The same applies if the engine speed remains constant whilst the
alternator is overloaded due to excessive current being drawn, or a very low power factor load.

The SCOOP feature of the regulator is built in to protect the alternator against such overloads. It senses
the average voltage being applied to the alternator exciter winding, and if this applied voltage exceeds a
pre-set safe maximum value, the SCOOP inhibits the triggering of the thyristor which controls the current
supply to the exciter winding. The result is the alternator output voltage falls to approximately 50 volts.

Allowance is made for temporary overloads, such as those encountered when starting electric motors, by
the addition of a built-in delay. This factory pre-set, non-adjustable, feature delays the operation of the
SCOOP function for approximately 20 seconds.

If the alternator output voltage is lost due to the operation of SCOOP the voltage will remain at its SCOOP
level until the generating set is shut down. Stopping the set will automatically reset the function. If the
reason for the operation of SCOOP is not immediately obvious, it is advisable that an investigation is
carried out before any attempt to restart is made. If the cause of the failure has not been determined and
rectified, the set will again lose output voltage approximately 30 seconds after restart.

The operation of SCOOP and/or certain short circuit conditions may result in the loss of residual
magnetism in the alternator exciter field. In such cases, refer to the section entitled "Repolarisation".

Under no circumstances must any voltage from an outside source be applied to the voltage
regulator field terminals. Failure to observe this point may result in permanent damage to the regulator.

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