Mosa RENTAL GE 50 KR-5, Use And Maintenance Manual

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6. Operation
6. Operation
WARNING
•
Before starting the machine, carefully read section
“2. Safety”.
•
It is forbidden to connect the set to the public grid and/or other source of electricity.
6.1 Operating conditions
6.1.1 Power
The electrical power of the generating set, expressed in kVA, is the available output power at the reference
environmental conditions and at the rated values of: voltage, frequency, power factor (cos ϕ).
There are different types of power established by ISO 8528-1 and 3046/1:
•
PRIME POWER (PRP)
•
STAND-BY POWER
• COP
See
“3.2 Technical data”
.
*
Important
•
When using the generating set, do not exceed the declared powers, paying particular attention when
powering multiple loads at the same time.
6.1.2
Voltage
Alternators with Electronic Adjustment (AVR)
In these types of generating sets, the voltage accuracy is maintained within ±1.5% with speed variation
between -10% and +30% and with balanced loads.
The voltage remains constant both without load and with connected loads that have a cos φ between 0.8 ÷1.
The insertion and release of the load causes a change of transient voltage lower than 15%, with return to the
rated value within 0.2-0.3 seconds.
6.1.3 Frequency
Frequency is a parameter directly dependent on engine revolutions.
With a 4-pole alternator, you have a frequency of 50/60 Hz with a rotational speed of 1500/1800 rpm.
The electronic speed regulator, present on the engine of the generating set, maintains the constant speed
of rotation in all operating conditions, unladen or with load (isochronous operation), and therefore also the
frequency of the electrical system remains constant, with a maximum variation of ±0.25% in static conditions.
Power factor - cos ϕ
The power factor is a data that depends on the electrical characteristics of the load.
It indicates the ratio between the Active Power (kW) and the Apparent Power (kVA).
The apparent power is the total power required for the load, given by the sum of the active power delivered
by the engine (after the alternator has transformed the mechanical power into electrical power) and the Re-
active Power (kVAR) delivered by the alternator.
The rated value of the power factor is cos ϕ = 0.8.
For different values between 0.8 and 1, it is important during use not to exceed the declared active power
(kW) so as not to overload the engine of the generating set; the apparent power (kVA) will decrease propor
-
tionally to the increase in cos ϕ.