Galvanic Isolation (Pelv) - Danfoss VLT FC 102 Series Design Manual

Introduction to VLT® HVAC D...
Basic standard
Acceptance criterion
Voltage range: 200–240 V, 380–500 V, 525–600 V, 525–690 V
Line
Motor
Brake
Load sharing
Control wires
Standard bus
Relay wires
Application and serial
communication options
LCP cable
External 24 V DC
Enclosure
Table 2.23 EMC Immunity Form
1) Injection on cable shield
AD: Air Discharge
CD: Contact Discharge
CM: Common mode
DM: Differential mode

2.10 Galvanic Isolation (PELV)

2.10.1 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), with the exception of
the grounded Delta leg above 400 V.
Galvanic (ensured) isolation is obtained by fulfilling requirements for higher isolation and by providing the relevant
creepage/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
Figure 2.34):
To maintain PELV all connections made to the control terminals must be PELV, e.g., thermistor must be reinforced/double
insulated.
MG11BC22
Design Guide
Electrical Surge
interference IEC 61000-4-5
IEC 61000-4-4
B B
2 kV/2 Ω DM
4 kV CM
4 kV/12 Ω CM
4 kV CM 1)
4 kV/2 Ω
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 1)
2 kV/2 Ω
2 kV CM 1)
2 kV/2 Ω
0.5 kV/2 Ω DM
2 V CM
1 kV/12 Ω CM
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Danfoss A/S © Rev. 06/2014 All rights reserved.
ESD Radiated electromagnetic
IEC field
61000-4-2 IEC 61000-4-3
B A
— —
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— —
— —
— —
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— —
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8 kV AD
10 V/m
6 kV CD
RF common
2 2
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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