Beta Marine BetaGen 10, Installation Manual, Page: 10 / 116

8
Specification Parameters
The Performance Class of the generating set is specified
in International Standard ISO 8528. BetaSet and BetaGen
generating sets perform within the limits of
ISO 8528
Class G1
.
1.1 Frequency Regulation:
Frequency (Hz) regulation depends upon the loading and
engine governing. Hz is directly related to engine speed.
Steady state – off load can be up to 8% above the full
load Hz. (On many Beta generating sets the off load Hz
will be within 5% above the full load speed although this
cannot be guaranteed especially on the smaller sets). This
is called frequency droop.
• Steady state Hz band is
≤
2.5%.
• The rated Hz tolerance band is 3.5%
Accordingly, if the full load speed of the engine is set
such that the output from the generator is produced
at 50Hz (which is 1500 rpm engine speed for a 4-pole
generator) the no load Hz could be as much as 54Hz. At
loads between full load and no load the frequency will lie
between these two figures depending on the magnitude
of the load.
The frequency should be stable, at any steady state load,
within a band width of 2.5% (1.25Hz). So at 100% load,
providing the engine speed is set to produce 50Hz at full
load, the frequency can vary within this 2.5% band. For
example between 49.4 and 50.6Hz.
1.2 Dynamic Behaviour:
• Transient speed increase when 100% load is removed
as a percentage from previous level < 18%.
• Recovery time to new steady state speed band < 10
seconds.
• Transient speed decreases when 100% load is added
as a percentage from previous level < -15%
• Recovery time to new steady state speed band < 10
seconds.
1.3 Waveform:
Waveform is not a significant factor for machines for
domestic or light industrial applications, the reason being
that generator set manufacturers can do little to influence
the waveform because it depends upon the cyclic
irregularity of the generating set (inherent in the design
of the engine and inertia of the set) and the construction
of the generator itself which inherently causes harmonics.
The connected load can also affect the waveform.
No limits are specified for waveform on these generating
sets.
1.4 Voltage Regulation:
‘Steady State’ voltage regulation will be ± 2.5% (± 3.5%
on the smallest machines) of nominal set voltage at
any load up to 100% provided the power factor lies in
the range 0.8 to unity and provided that the engine is
performing in accordance with the parameters detailed
in paragraph 1.1 of this specification. In reality voltage
regulation will, in many cases, be better than this.
Power factors outside the range 0.8 to unity can affect
voltage regulation. Power factor is a function of the
connected load. Resistive loads, such as heaters, are
unity power factor loads where their kVA equals kW. To
obtain the kW rating of any generator set multiply the kVA
rating x 0.8. Outputs to loads having other power factors
may result in specifications outside the limits mentioned
herein.
NB: BetaSet-BetaGen 4/2 and 6/2 are unity factor
machines - kVA = kW.
1.5 Power & Voltage:
• Voltage is that set and measured at the generator
terminals when the machine is connected to a ‘pure’
load whose power factor lies between 0.8 and unity.
(In the UK the nominal voltage is 400v ± 6%, 3-phase,
test voltage for single phase sets can lie between 218v
and 244v, hence the nominal voltage to be used under
steady state conditions will be 231v on full load).
• Voltage performance of Beta Marine generating sets
will be well within the limits specified by ISO 8528
Class G1 . When large loads are applied the voltage
will dip and provided such loads are not too large will
recover in a few seconds. In correlation when load is
suddenly removed the voltage will rise with similar
recovery time.