Atlas Copco QAS 14, Instruction Manual

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IT-relay
The generator is wired for an IT network i.e. no
supply lines of the power supply are directly earthed.
A failure in insulation resulting in a too low insulation
resistance, is detected by the insulation monitoring
relay.
Q1 .......Circuit breaker for X1
Interrupts the power supply X1 when a
short-circuit occurs at the load side, or when
the overcurrent 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 (400 V AC)
Terminals L1, L2, L3, N (= neutral) and PE
(= earthing), hidden behind the control panel
door and behind a small transparent door.
N14 .....Insulation monitoring relay
Checks the insulation resistance and
activates Q1 when the insulation resistance
is too low.
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.
Not available for the Box A
Compact 60 Hz units.
The generator shall not be operated
with other networks (such as TT or
TN). Doing so will cause tripping of
the insulation monitoring relay.
The generator is wired for an IT
network i.e. no supply lines of the
power supply are directly earthed.
A failure in insulation resulting in
too low an insulation resistance, is
detected by the insulation
monitoring relay.
At each start-up and any time a new
load is connected, the insulation
resistance must be verified. Check
for the correct setting of the
insulation monitoring relay. (factory
set at 13 k
Ω )
!
!
L1 L2 L3 N PE
H0
S20
F10
Q1
X1
N14
P4 P3
0 0
20
40
80
100
200
V
A
300
400
500
Qc 1002
145
N14
Q1
S2
X1