Mitsubishi Electric MELSERVO EMC Instruction sheet

Mitsubishi Electric AC Servo System
K
EMC Installation
Guidelines

1
CONTENTS
1. SUMMARY 1 - 1 to 1 - 2
2. EMC DIRECTIVE 2 - 1 to 2 - 2
3. EMC COUNTERMEASURES 3 - 1 to 3 -10
3.1 Basic EMC countermeasures .................................................................................................................. 3 - 1
3.2 Cabinet design ......................................................................................................................................... 3 - 1
3.3 Filter wiring and installation...................................................................................................................... 3 - 4
3.4 Cable treatment........................................................................................................................................ 3 - 6
4. EMC COUNTERMEASURE PARTS 4 - 1 to 4 - 12
4.1 Noise filter (For controller power supply)................................................................................................. 4 - 1
4.2 EMC filter (For servo amplifier power supply) ......................................................................................... 4 - 1
4.3 Ferrite core (Data line filter) ..................................................................................................................... 4 - 7
4.4 Shield clamp fitting ................................................................................................................................... 4 - 8
4.5 Line noise filter ......................................................................................................................................... 4 - 8
4.5.1 Connection example ......................................................................................................................... 4 - 8
4.5.2 Precautions....................................................................................................................................... 4 -10
4.6 Surge protector........................................................................................................................................ 4 -11
5. CONNECTION EXAMPLE FOR EMC COUNTERMEASURES 5 - 1 to 5 - 4
5.1 For 22kW or less of 1-axis ....................................................................................................................... 5 - 1
5.2 For 1kW or less of multi axis.................................................................................................................... 5 - 2
5.3 For 30kW or more .................................................................................................................................... 5 - 3
6. SUPPLEMENT 6 - 1 to 6 - 6
6.1 Reasons why the shield is grounded on both the cabinet side and the servo motor chassis side ....... 6 - 1
6.1.1 Grounding the shield at the servo amplifier side only ...................................................................... 6 - 1
6.1.2 Grounding the shield at both ends of the cable................................................................................ 6 - 2
6.2 Reasons why the grounding position in the cabinet is specified to be 10 cm or less from the
cabinet exit ............................................................................................................................................... 6 - 3

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6.3 Reasons why the shield must be grounded with the P clip or U clip...................................................... 6 - 3
6.4 Connecting multiple servo amplifiers to one EMC filter (1: n connection) ............................................. 6 - 4
6.4.1 Selection method............................................................................................................................... 6 - 4
6.4.2 Selection example ............................................................................................................................. 6 - 5

1 - 1
1. SUMMARY
1. SUMMARY
We have carried out EMC standard compliance confirmation tests with the servo amplifier in the installation
environment described in this manual. After incorporating the servo amplifier in the machine or equipment,
confirm the EMC standard compliance of the entire machine or equipment on customer side.
For the EMC countermeasures, refer to this guideline or the instruction manual of the servo amplifier used.

1 - 2
1. SUMMARY
MEMO

2 - 1
2. EMC DIRECTIVE
2. EMC DIRECTIVE
Mitsubishi Electric general-purpose AC servo MELSERVO complies with products standard EN 61800-3. This
directive largely regulates the following two withstand levels.
(1) Emission (EMI: Electromagnetic Interference)
Capacity to prevent output of obstructive noise that adversely affects external sources.
(2) Immunity (EMS: Electromagnetic Susceptibility)
Capacity to not malfunction due to obstructive noise from external source.
The details of each level are classified below.
Class Name Details Products
standard
Emission
(EMI)
Radiated noise Electromagnetic noise radiated through the air,
etc.
EN 61800-3
Conducted noise Electromagnetic noise discharged from power
supply line, etc.
Immunity
(EMS)
Electrostatic discharge immunity test
IEC 61000-4-2
Noise from a charged human body, etc.
Radiated, radio-frequency, electromagnetic
field immunity test
IEC 61000-4-3
Electromagnetic noise from wireless transmitters
or broadcasting companies, etc.
Electrical fast transient/burst immunity test
IEC 61000-4-4
Relay noise or electromagnetic noise caused by
live electricity being turned on or off, etc.
Immunity to conducted disturbances,
induced by radio-frequency fields
IEC 61000-4-6
Electromagnetic noise flowed from power supply
wires or earthing wires, etc.
Power-frequency magnetic field immunity
test
IEC 61000-4-8
Electromagnetic noise of 50/60Hz power supply
frequency, etc.
Voltage dips, short interruptions and
voltage variations immunity tests
IEC 61000-4-11
Power supply drop, etc.
Surge immunity test
IEC 61000-4-5
Electromagnetic conducted noise discharged by
thunder, etc.

2 - 2
2. EMC DIRECTIVE
MEMO

3 - 1
3. EMC COUNTERMEASURES
3. EMC COUNTERMEASURES
CAUTION
The servo amplifier must be installed in the metal cabinet.
3.1 Basic EMC countermeasures
POINT
According to the NFPA79 approved by the United States, when the shielded
wire is not used for wiring between a servo amplifier and a servo motor, the
wiring must be insulated from wiring of other control or signal circuits.
(Example: 100 mm or more for 20 A or less)
Take the following measures firmly as EMC countermeasures.
(1) Install the device in a sealed metal cabinet.
(2) Install a noise filter.
(3) Accurately earth the device.
(4) Use shielded wires for cables and wires.
(5) Separate the primary-side wiring and the secondary-side wiring as far as possible.
(6) Install the surge protector. (Refer to section 4.6.)
3.2 Cabinet design
The servo is a complex component incorporated into another machine. It must always be installed in a cabinet.
The design of the cabinet is a very important factor for EMC countermeasures, so please take the following
points into consideration.
(1) Use a metal cabinet.
(2) Accurately earth the cabinet unit with a thick and short cable.

3 - 2
3. EMC COUNTERMEASURES
(3) Weld or screw close the joining sections of the cabinet's top plate and side plate. Keep the joining
clearance to 10cm or less. The diameter of the openings on the cabinet such as the ventilation hole should
be 10cm or less. If there are holes larger then this, plug them with metal plates or punched metal. In this
case, such as when painted surfaces are to be connected, make sure that there is a good electrical
connection to prevent antenna effect.
Example)
Remove paint
Hole exceeding
10cm
Faraday cage effect grill
Provide an electrical continuity.
(4) The door of the cabinet must be accurately earthed with the cabinet. If the door earthing is insufficient, the
door itself will act as a large antenna and will radiate noise.
Take the following measures for this.
1) Use a metal door.
2) Connect the door and cabinet with thick braided wire at as many points as possible.
3) Use an EMI gasket or conductive packing for the contact between the door and cabinet.
Cabinet
Metal cabinet
Enforce conductance treatment on
sections that the EMI gasket contacts.
EMI gasket
Packing
door

3 - 3
3. EMC COUNTERMEASURES
(5) To take preventive measures against the noise of the input power source cable in the cabinet, install the
shielding partition at nearby site where the power is input so that the input power cable does not receive
harmful effects of the radiated noise.
AC input
Filter MCCB
Radiated noise
Cabinet
AC input
Filter MCCB
Radiated noise
Shielding
partition
Controller Servo amplifier Controller Servo amplifier
Cabinet
The power supply line noise is
eliminated by the filter, but cable
contains noise again because of the
noise radiated in the cabinet.
Use a metal plate, etc., for the
shielding partition.
Make sure there are no gaps.