Galvanic Isolation (Pelv); Pelv - Protective Extra Low Voltage - Danfoss VLT AQUA Drive Series Design Manual

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VLT AQUA Drive Design Guide
In order to document immunity against electrical interference from electrical phenomena, the following immunity tests have been made on a system
consisting of a frequency converter (with options if relevant), a screened control cable and a control box with potentiometer, motor cable and motor.
The tests were performed in accordance with the following basic standards:
• EN 61000-4-2 (IEC 61000-4-2): Electrostatic discharges (ESD): Simulation of electrostatic discharges from human beings.
• EN 61000-4-3 (IEC 61000-4-3): Incoming electromagnetic field radiation, amplitude modulated simulation of the effects of radar and radio
communication equipment as well as mobile communications equipment.
• EN 61000-4-4 (IEC 61000-4-4): Burst transients: Simulation of interference brought about by switching a contactor, relay or similar devices.
• EN 61000-4-5 (IEC 61000-4-5): Surge transients: Simulation of transients brought about e.g. by lightning that strikes near installations.
• EN 61000-4-6 (IEC 61000-4-6): RF Common mode: Simulation of the effect from radio-transmission equipment joined by connection cables.
See following EMC immunity form.
Voltage range: 200-240 V, 380-480 V
Basic standard
Acceptance criterion
Line
Motor
Brake
Load sharing
Control wires
Standard bus
Relay wires
Application and Fieldbus op-
tions
LCP cable
External 24 V DC
Enclosure
AD: Air Discharge
CD: Contact Discharge
CM: Common mode
DM: Differential mode
1. Injection on cable shield.
Table 2.2: Immunity

2.11 Galvanic isolation (PELV)

2.11.1 PELV - Protective Extra Low Voltage

PELV offers protection by way of extra low voltage. Protection against electric shock is ensured when the electrical supply is of the PELV type and the
installation is made as described in local/national regulations on PELV supplies.
All control terminals and relay terminals 01-03/04-06 comply with PELV (Protective Extra Low Voltage) (Does not apply to grounded Delta leg above 400
V).
Galvanic (ensured) isolation is obtained by fulfilling requirements for higher isolation and by providing the relevant creapage/clearance distances. These
requirements are described in the EN 61800-5-1 standard.
The components that make up the electrical isolation, as described below, also comply with the requirements for higher isolation and the relevant test
as described in EN 61800-5-1.
The PELV galvanic isolation can be shown in six locations (see illustration):
In order to maintain PELV all connections made to the control terminals must be PELV, e.g. thermistor must be reinforced/double insulated.
1. Power supply (SMPS) incl. signal isolation of U
intermediate current voltage.
Burst Surge
IEC 61000-4-4 IEC 61000-4-5
B B
2 kV/2 Ω DM
4 kV CM
4 kV/12 Ω CM
4 kV CM 4 kV/2 Ω 1)
4 kV CM 4 kV/2 Ω 1)
4 kV CM 4 kV/2 Ω 1)
2 kV CM 1)
2 kV/2 Ω
2 kV CM 1)
2 kV/2 Ω
2 kV CM
2 kV/2 Ω 1)
2 kV CM
2 kV/2 Ω 1)
2 kV CM 1)
2 kV/2 Ω
0.5 kV/2 Ω DM
2 kV CM
1 kV/12 Ω CM
— —
, indicating the
DC
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MG.20.N5.02 - VLT is a registered Danfoss trademark
2 Introduction to VLT AQUA Drive
ESD Radiated electromagnetic field
IEC IEC 61000-4-3
61000-4-2
B A
— —
— —
— —
— —
— —
— —
— —
— —
— —
— —
8 kV AD
10 V/m
6 kV CD
2. Gate drive that runs the IGBTs (trigger transformers/opto-cou-
plers).
2
RF common
mode voltage
IEC 61000-4-6
A
10 V
RMS
10 V
RMS
10 V
RMS
10 V
RMS
10 V
RMS
10 V
RMS
10 V
RMS
10 V
RMS
10 V
RMS
10 V
RMS
—
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