Atlas Copco QAS 275-325, Instruction Manual

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Output terminal board
The cubicle provides a terminal board for easier
connection of cables. It is situated below the control
and indicator panel.
S2 ....... Emergency stop button
Push the button to stop the generator in case
of an emergency. When the button is
pressed, it must be unlocked, by turning it
anti-clockwise, before the generator can be
restarted. The emergency stop button can be
secured in the locked position with the key,
to avoid unauthorized use.
N13 .....Earth leakage relay
Detects and indicates an earth fault current
and activates the main circuit breaker Q1.
The detection level can be set at 30 mA fixed
with instantaneous trip but can also be
adjusted between 30 mA and 250 mA with
time delayed (0 - 1 sec) trip. N13 has to be
reset manually after eliminating the problem
(reset button marked R). It can be overridden
by means of the earth leak switch (S13,
labelled I

N) but has to be tested monthly by
pushing test button T13.
S13 .....Earth relay lock-out switch (N13)
This switch is located inside the cubicle and
is labelled I

N.
Position O: No de-energising of the main
circuit breaker Q1 when an earth fault
occurs.
Position 1: De-energising of the main circuit
breaker Q1 when an earth fault occurs.
Q1 .......Main circuit breaker
Interrupts the power supply X1 when a
short-circuit occurs at the load side, or when
the overcurrent (QAS 275: 400 A/ QAS 325:
470 A) protection is activated. When
activated, Q1 interrupts the three phases
towards X1. It must be reset manually after
eliminating the problem.
X1 .......Main power supply
Terminals L1, L2, L3, N (= neutral) and PE
(= earthing), behind a small transparent
door.
L1L2
OFF
L1-N
L2L 3 L2-N
L 3 L1
LL LN
L 3 -N
Q3 Q6
Q2
Q1
Q4 Q5
N13
X2
X4
X3
X6
X5
S 2
N13
Q1
S 13
X1
Position O on switch S13 will only
be used in conjunction with an
external earth fault protection unit
(e.g. integrated in a distribution
board) or when the generator is
used in parallel.
The earth fault protection on the
single phase outlet socket is not
affected by the switch S13.
If S13 is in position O, proper
earthing is of the utmost importance
for the safety of the user.
Eliminating any earth fault
protection can lead to serious injury
or even death for anybody touching
the unit or the load.