Winco MDS50E3/B - Manual (Page 7)

Page 5
Amp circuit breaker. This receptacle is wired in series
with the GFCI receptacle which provides it with GFCI
protection.
3. 240 Volt 20 Amp 3 wire twist lock, NEMA Spec L6-
20. This twistlock receptacle is protected by a two pole
240 volt circuit breaker.
4. 120/240 Volt 50 Amp 4 wire twistlock. This receptacle
is rated for dual voltage, 120 or 240 volt use. It is a four
wire receptacle, with a center grounding pin. Four wire
drop cords plugged into this receptacle may be split into
120 volt receptacles at a distribution box. This receptacle
is protected by a two pole 50 amp circuit breaker mounted
just above it. THIS RECEPTACLE UTILIZES A SPECIAL
HUBBELL PLUG. (HUBBELL PART NUMBER “CS
6365”.)
C. FULL POWER LOAD CONNECTIONS and
BREAKERS
This Mobile Diesel Power System is equipped with both
high voltage (480) and low voltage (208/240) main line
breakers. The breakers are interlocked with a lockable
bar to insure that only one breaker can be turned on at a
time.
A full power output terminal block is provided. This
terminal block is located below the main power breakers
and is accessible through the access door located just
below the main line breakers. If this access door is
opened with the unit running a safety switch will disable
the 12 volt system shutting the unit down. This door must
remain closed and latched at all times during normal
operations.
DANGER: PERSONAL INJURY
This unit will start as soon as the door is closed if the
start switch is in the run position. Do not use the switch
on this door to shutdown a unit to connect to the full load
terminal block , this is a safety switch only.
E. VOLT/HERTZ VOLTAGE REGULATOR
The purpose of the voltage regulator is to maintain the
voltage output of the Generator Set within a specified
percentage of its rated output from no load to full load.
The voltage regulator controls the voltage output of the
main generator by regulating the amount of current
delivered to the exciter field.
1. Location -Access to the voltage regulator assembly
is gained by removing the control panel access door
located through the left rear housing door.
2. Description - The Basler model VR63-4C voltage
regulator is a completely encapsulated unit. The regulator
controls the DC exciter field voltage on brushless genera-
tors to regulate the output voltage. Regulation is provided
by sensing the generator output voltage, converting it to
a DC signal and comparing the signal to a reference
voltage signal. An error signal is developed and used to
control the DC field power in order to maintain a constant
generator output.
3. Operation of Voltage Regulator - The voltage
regulator has been installed in the Mobile Diesel Genera-
tor set and tested at the factory prior to shipment. No
additional setup is required when changing from one
voltage to another. The only adjustment required is to
fine tune the exact voltage you want using the voltage
adjustment rheostat located on the front panel. The
adjustment range is 10% of the nominal voltage.
Some minor changes must be made for 50 cycle opera-
tion. Refer to 50 Hz operation later in this section for
setup procedures.
a. During periods of operation at reduced speed use
the field circuit breaker to remove the power from the
regulator.
b. If the exciter field voltage exceeds 95 VDC, the
regulator senses over excitation and automatically
removes the field current after a time delay. This time
delay is inversely proportional to the magnitude of the
detected over voltage condition. At approximately 140
VDC, the field voltage is removed instantaneously.
Upon detection of over excitation and the resulting field
voltage shutdown, the regulator will not reset or return to
an operational condition until the generator output voltage
drops to less than 6 VAC for ten seconds (minimum). TO
ACCOMPLISH THIS ON A MOBILE DIESEL GENERA-
TOR SET THE FIELD CIRCUIT BREAKER MUST BE
TURNED OFF FOR TEN SECONDS.
OPERATING THE UNIT
A. SELECTING THE CORRECT VOLTAGE
A variety of voltages are available from the three position
selector switch. The three basic connection patterns are,
Delta (120/240), Low or Parallel WYE (120/208), and High
WYE (277/480). Single phase 120/240 is available with
the switch in the 120/240 (Delta) position.
Before connecting this unit to a distribution panel or any
other loads, be sure you have the selector switch set for
the right voltage and locked. If you have any doubts as to