Cramaco G2R 400 Serie Manual De Instrucciones página 11

CRAMACO
®
Rev 0
D) In this conditions the generator should assume consecutive parallel runs, without change any element of control,
except for abnormal variations of the bars in which is connected.
2.2.5. ELIMINATION OF RADIAL INTERFERENCE
The generators carry out a "G" degree as is established in the standards. Logically, generators can be supply, as a
request, with higher degrees. "N" or "K". The connections of this filter mechanism are available on the drawing
provided with the machine. When the resistance of isolation is measure, it will be request to turn off this capacitor.
2.2.6. REFERENCE VOLTAGE ADJUSTMENT
The generators are provide with the connection of an external potentiometer (1 KΩ-2 W, intercalate in the P/Q leads)
as a reference voltage adjustment that lets change the voltage between +/-5%.
This adjustment can be put on the same terminal box control panel. This equipment it's supplied just by request, for
generators that runs in parallel is recommend to block it after the first use (see paragraph 2.2.4.), having access only
authorised personal.
2.2.7. EXCITATION
The generators are self excited by remnant magnetism, the residual voltage is a lot higher in generator without
exciter. This residual value can change importantly, depending basically in the previous excitation and the quality of
the ferromagnetic lamination. So that, if any chore has to be executed in a brushless generator is absolutely
indispensable to stop the machine, before to do any work. The field disconnection is not enough.
2.3. AUTOMATIC VOLTAGE REGULATOR (AVR)
The A.V.R. should:
⇒ Maintain constantly independent from the load, the voltage on the terminals of the generator for the isolated work
and to produce the drop of tension needed for a correct parallel operation.
⇒ Make stable the tension against wavering caused by the variations of short period loads. The alternal voltage of
auxiliary winding is rectify and transmitted in a controlled way to the winding of the exciter
The machine can operate with different voltages and frequencies.
2.3.1 VOLTAGES
The connection and voltages graphics are on drawings: 19762 and 19769. Simple star connection only by order.
VERY IMPORTANT
If you need to change voltage to obtain a new value of voltage, you must follow the mentioned drawings, and after
this, adjust it with the machine running, the potentiometer incorporated to the regulator and identify as "VOLTS" to
the wished value that must be in the range indicated on the plane.
2.3.2 FREQUENCIES
The AEC 42-7 regulator admit 50 or 60 HZ operation, must to have short-circuited 50-50 leads for 50 HZ condition,
otherwise the regulator will function on 60 HZ. Also it has a frequency compensation which improve load pickup
performance by restraining voltage recovery until frequency has also started to recover. This compensation maintain
constant u/f.
2.3.3 OVEREXCITATION SHUTDOWN
This protection automatically remove field current after a delay time, the time delay is inversely proportional to the
magnitude of the detected overvoltage condition, this protection works if D-N bridge is open, and is recommended
for parallel devices.
2.3.4 FUSE
It's situated outside the regulator, it's type: 5.0 A – 240 Vca – 3AG 6.3 × 32 mm.
VERY IMPORTANT
In case of to change the fuse, do it with the machine off.
3. PREVIOUS CHECKING OF THE ASSEMBLING
This section gives information about unpacking, inspection of the stuff, localisation, line up, electrical connections,
assembling and direction of rotating.
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