Terminal Board Connections; Electronic Regulator - Westerbeke 65A-FOUR Service Manual

ELECTRONIC REGULATION SR7-2G AVR
ADJUSTABLE THRESHOLD
OVERLOAD PROTECTION
AMP FUSE
ADJUSTABLE THRESHOLD
OF UNDERSPEED
PROTECTION INTERVENTION
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DO
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FOR 60Hz
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REMOVE FOR 50Hz
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DESCRIPTION
The voltage regulator (AVR) ensures optimum AC generator
performance. TIlis advanced design AVR is equipped with
circuitry protection to guard against operating conditions tllat
could be detrimental to the AC generator. The following
information details the voltage regulators adjustments and
connections. These procedures should be performed by a
qualified technician.
TERMINAL CONNECTIONS
#1. Excitation field DC negative.
#2.
Exciter field jumper to 3 if the regulator AC supply
between S and 3A is less than 160 VAC.
#3. Exciter field DC positive.
#3A. Supply voltage to regulator (Ae).
#4.
Sensing voltage.
#5. Supply voltage to regulator (Ae).
#6.
Jumper to SA for 60 Hz operation.
#7. Not used.
#5B. Npt used.
#5C. Sensing voltage.
POSSIBLE CONNECTIONS
Exciter Field: The exciter field negative should be
connected to terminal 1 of the electronic regulator (normally
dark blue or black), while the positive (nonnally red or
yellow) should be connected to terminal 3.
Supply: There are two possibilities.
1. The supply coincides with the sensing. In tllis case the
SR712 supply should be connected to tenninals 3 and S
(in case of three-phase generators, terminal S is normally
connected Witll the star
point).
Ternnnals 3 and 4 should
be connected to each otller in such a way that the supply
is also sensing. This connection in necessary when the
generator does 1I0t have auxiliary winding for supplying
the regulator.
2. The supply and sensing separate. Tins is the case of a
generator equipped with auxiliary winding for regulator
supply. Supply is always connected to terminals 3 and 5
of the regulator.
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EXCITER FIELD
In both of these cases, tlle SR7/2 supply can vary from 80 to
270 VAC. But it should
be
noted that terminals 2 and 3
should be bridged for supply with voltage between 80 and
160 VAC, while the same terminals should be left open if the
voltage is between 160 and 270 VAC.
Sensing: Sensing should be connected to terminals 4 and S
and can vary from 80 to 350 VAC. The sensing is single
phase only and therefore is normally connected to one
alternator phase.
Operation at 60
Hz:
When operating at 60 Hz, terminals SA
and 6 should be connected to each other in order to keep tlle
low frequency protection correctly regulated.
A
WARNING:
Be aware that high voltages may be
present. Take all necessary precautionms to safe guard
against electrical hazards.
FUNCTIONS OF THE REGULATOR POTENTIOMETERS
Volt: Witll this potentiometer, it is possible to adjust the
voltage generated by the alternator in a very simple way. If
the screw is tumed clockwise, the voltage increases, if tlle
screw is turned counterclockwise
it
decreases.
Stab: This potentiometer optinlizes altemator performance.
If turned clockwise, the stability decreases and the response
time decreases but the voltage tends to be less stable. If
turned cOllnterclockwise, the response time increases and the
voltage tends to be more stable.
In order to adjust tlIis potentiometer cOlTectly, we advise
using the following metllod.
1. The generator must be working, starting frolll zero load
and the potentiometer must be at
maximum
stability
(turned fully counterclockwise).
2. Slightly tum clockwise until tlle light generated by tlle
filament lamp oscillates, at this point, tUIll tlle
potentiometer slowly counterclockwise until tlle light
stabilizes.
Engines & Generators
85