Connecting The Generator - Atlas Copco QAS108 Pd(S) Mk II Manual De Instrucciones

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ONNECTING THE GENERATOR
Precautions for non-linear and sensitive loads
Non-linear loads draw currents with high contents in
harmonics, causing distortion in the wave form of the voltage
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generated by the alternator.
The most common non-linear, 3-phase loads are thyristor/
rectifier-controlled loads, such as convertors supplying
voltage to variable speed motors, uninterruptable power
supplies and Telecom supplies. Gas-discharge lighting
arranged in single-phase circuits generate high 3rd
harmonics and risk for excessive neutral current.
Loads most sensitive to voltage distortion include incande-
scent lamps, discharge lamps, computers, X-ray equipment,
audio amplifiers and elevators.
Consult Atlas Copco for measures against the adverse
influence of non-linear loads.
Quality, minimum section and maximum length of cables
The cable connected to the terminal board of the generator
must be selected in accordance with local legislation. The
type of cable, its rated voltage and current carrying capacity
are determined by installation conditions, stress and ambient
temperature. For flexible wiring, rubber-sheathed, flexible
core conductors of the type H07 RN-F (Cenelec HD.22) or
better must be used.
The following table indicates the maximum allowable 3-phase
currents (in A), in an ambient temperature of 40 °C, for cable
types (multiple and single core PVC insulated conductors
and H07 RN-F multiple core conductors) and wire sections as
listed, in accordance with VDE 0298 installation method C3.
Local regulations remain applicable if they are stricter than
those proposed below.
2
Wire section (mm )
2,5 4
Max. current (A)
Multiple core 22 30
Single core 25 33
H07 RN-F 21 28
The lowest acceptable wire section and the corresponding
maximum cable or conductor length for multiple core cable
or H07 RN-F, at rated current (145 A), for a voltage drop e
lower than 5 % and at a power factor of 0.80, are respectively
2
50 mm and 210 m. In case electric motors must be started,
oversizing the cable is advisable.
The voltage drop across a cable can be determined as
follows:
3 .I.L.(R. cosϕ + X.sinϕ)
e =
1000
e = Voltage drop (V)
I = Rated current (A)
L = Length of conductors (m)
R = Resistance (Ω/km to VDE 0102)
X = Reactance (Ω/km to VDE 0102)
6 10 16 25 35 50
38 53 71 94 114 138 176 212
42 57 76 101 123 155 191 228
36 50 67 88 110 138 170 205
Connecting the load
Site distribution panel
If outlet sockets are required, they must be mounted on a site
distribution panel supplied from the terminal board of the
generator and in compliance with local regulations for power
installations on building sites.
Protection
For safety reasons, it is necessary to provide an isolating
switch or circuit breaker in each load circuit. Local legislation
!
may impose the use of isolating devices which can be locked.
– Check whether frequency, voltage and current comply
with the ratings of the generator.
– Provide for the load cable, without excessive length, and
lay it out in a safe way without forming coils.
– Open the door of the control and indicator panel and the
transparent door in front of the terminal board X1.
– Provide the wire ends with cable lugs suited for the cable
terminals.
– Loosen the cable clamp and push the wire ends of the
load cable through the orifice and clamp.
– Connect the wires to the proper terminals (L1, L2, L3, N
and PE) of X1 and tighten the bolts securely.
– Tighten the cable clamp.
– Close the transparent door in front of X1.
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NSTRUCTION MANUAL
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