Planning the electrical installation
83
Insulation requirements for the motor temperature sensor circuit
WARNING! IEC 60664 requires double or reinforced insulation between live parts
and the surface of accessible parts of electrical equipment which are either non-
conductive or conductive but not connected to the protective earth.
To fulfil this requirement, the connection of a thermistor (and other similar
components) to the digital inputs of the drive can be implemented in three alternate
ways:
1. There is double or reinforced insulation between the thermistor and live parts of
the motor.
2. Circuits connected to all digital and analogue inputs of the drive are protected
against contact and insulated with basic insulation (the same voltage level as the
drive main circuit) from other low voltage circuits.
3. An external thermistor relay is used. The insulation of the relay must be rated for
the same voltage level as the main circuit of the drive. For connection, see the
firmware manual.
Protecting the drive against ground faults in the drive, motor or motor
cable
Both the supply unit and the inverter unit are equipped with an internal ground fault
protective function to protect the drive against ground faults in the drive, motor and
motor cable. (This is not a personnel safety or a fire protection feature.) Both ground
fault protective functions can be disabled; refer to the IGBT Supply Control Program
Firmware Manual (3AFE68315735 [English]) and the firmware manual of the drive
control program respectively.
Note: The EMC filter (if present) includes capacitors connected between the main
circuit and the frame. These capacitors and long motor cables increase the ground
leakage current and may cause fault current circuit breakers to function.
Implementing the emergency stop function
The drive can be equipped with category 0 and 1 emergency stop options (+Q951,
+Q952, +Q963 and +Q964). Install the emergency stop devices at each operator
control station and at other operating stations where emergency stop may be
needed. Pressing the stop key ( ) on the control panel of the drive, or turning the
operating switch of the drive from position “1” to “0” does not generate an emergency
stop of the motor or separate the drive from dangerous potential.
For more information, see Wiring, start-up and operation instructions of safety
options (+Q950, +Q951, +Q952, +Q963, +Q964, +Q967 and +Q968) for ACS800
cabinet-installed drives (3AUA0000026238 [English]).
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