Atrump AL52, Operation & Maintenance Manual, Page: 13 / 110

1-8
Machine Safety Regulation
1.3 Electrical Safety Description
To assure the safety of NC operation, please note the followings:
1.3.1 Wiring:
1.3.1.1 Ensure that the electrical conductors used is equivalent or superior to the
performance rating described in maintenance manual.
1.3.1.2 Only qualified engineer is allowed to connect the power cable.
1.3.1.3 Do not connect power cable which will cause noise on the power panel of
this machine such as welding machine and high frequency quench
machine.
1.3.1.4 Do not connect the power cable of this machine to the instantaneous
voltage drop power source or power panel.
1.3.2 Grounding
The cross-section of incoming supply protective conductor and each phase
conductors must be in accordance below table. It is important to identify the voltage
of source with machine. The voltage of connecting source terminal is marked
L1
,
L2
,
L3
on the electric cabinet.
A terminal for the connection of the external ground conductor is provided in the
vicinity of the associated phase conductor terminals with marked "
PE
".
The cross-section of a grounding wire need more than 10 mm 2 and resistance to
ground of less than 100 Ω . Gnerally, the NC machine should be grounded to a
separately grounding rod. If an independent ground can not be provided for the
machine, Please ground as follows:
1.3.2.1 Connect a single conductor to its own grounding terminal. This will avoid
some serious accidents resulting from ground currents which might
otherwise flow in the NC machine if a peripheral device should malfunction.
1.3.2.2 Be careful of when using concrete reinforcing rods as grounding points.
These reinforcing rods are often used to ground equipment because they
usually offer a resistance to ground of less than 100
Ω
. When doing so,
make connection as follows: (This also applies to connecting ground ires
to regular grounding terminal.)
1.3.2.3 Do not use the same grounding reinforcing rod or grounding terminal for
other devices since this could lead to line noise such as that produced by
welders or high frequency quenching machines.
1.3.2.4 Use a durable grounding terminal with an adequate electrical performance
rating.
1.3.2.5 Use a separate grounding wire of minimal length.
1.3.2.6 Check the resistance to ground by actual measurement. Be sure of less
than 100
Ω
if the single device is connected to its own grounding rod.
1.3.2.7 Desirable independent grounding: Independent grounding of several
equipment please refer to figure 1.