
5. INSTALLATION
B–65162E/03
120
Unless a machine is grounded, touching the machine may cause
electric shock. Take one of the following protective measures against
electric shock:
(a) Use a protective ground wire with a copper wire cross–sectional
area of no less than 10 mm
2
.
(b) Install a ground fault interrupter so that the power supply can be
disconnected immediately if a ground fault occurs.
(c) Add a protective grounding terminal to the cabinet to make a
double ground wire connection.
When using a ground fault interrupter, select an electromagnetic
ground fault interrupter with a low high–frequency component
sensitivity, or an electronic ground fault interrupter that can be used
with inverters.
Amplifiers have multiple protective grounding terminals (marked as
defined by 417–IEC–5019). These terminals are used to prevent electric
shock in case of dielectric breakdown, and are also used for functional
grounding to prevent noise.
All protective ground terminals must be connected to the protective
ground (PE) connection terminals in the power magnetics cabinet.
For how to connect the protective ground wires and the cross–sectional
areas of these wires, see Section 5.2.3.
Note that cables from cable terminals cannot be secured together with
protective ground terminals.
The amplifier uses IGBT (transistors) as an internal means of turning off
the power system; it does not use an electromechanical means.
Therefore, when an emergency stop circuit is configured, a line contactor
enabling electromechanical disconnection must be installed on the power
input line for feeding power to the power supply module so that a voltage
is applied to the control coil of the contactor via the contactor control
output of the power supply module.
Some amplifier failures may prevent the output relay of the power supply
module from being turned off even when the amplifier emergency stop
command input (*ESP) is driven low, thus disabling disconnection by the
line contactor.
The emergency stop circuit must disconnect power without fail. It must
have a redundant circuit configuration having a route through which the
line contactor is disconnected directly by the command generated by the
emergency stop operation switch, independent of the disconnection
function provided by the amplifier.
If the power line is disconnected during spindle rotation when a spindle
amplifier module is used, the spindle may not be able to be stopped
immediately by the power regeneration function, and may keep rotating
by the force of inertia. Therefore, on the redundant circuit side, a delay
function must be provided which is based on an off–delay timer
considering a normal stop time.
5.4.4
Protective Installation
5.4.5
Notes on the
Emergency Stop
Circuit Configuration