Galvanic Isolation (Pelv); Pelv - Protective Extra Low Voltage; Earth Leakage Current - Danfoss VLT HVAC Basic Drive FC 100 Series Design Manual

Introduction to VLT HVAC Ba...
S SC = 3 × R SCE × U mains × I equ =
at the interface point between the user's supply and the
2 2
public system (R
It is the responsibility of the installer or user of the
equipment to ensure, by consultation with the distribution
network operator if necessary, that the equipment is
connected only to a supply with a short-circuit power S
greater than or equal to specified above.
Other power sizes can be connected to the public supply
network by consultation with the distribution network
operator.
Compliance with various system level guidelines:
The harmonic current data in the table are given in
accordance with IEC/EN 61000-3-12 with reference to the
Power Drive Systems product standard. They may be used
as the basis for calculation of the harmonic currents'
influence on the power supply system and for the
documentation of compliance with relevant regional
guidelines: IEEE 519 -1992; G5/4.
2.7.7 Immunity Requirements
The immunity requirements for frequency converters
depend on the environment where they are installed. The
requirements for the industrial environment are higher
than the requirements for the home and office
environment. All Danfoss frequency converters comply
with the requirements for the industrial environment and
consequently comply also with the lower requirements for
home and office environment with a large safety margin.

2.8 Galvanic Isolation (PELV)

2.8.1 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 440V).
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
34
VLT HVAC Basic Drive Design Guide
3 × 120 × 400 ×
).
sce
MG.18.C2.02 - VLT
higher isolation and the relevant test as described in EN
I equ
61800-5-1.
The PELV galvanic isolation can be shown in 5 locations
(see illustration):
To maintain PELV all connections made to the control
terminals must be PELV, e.g. thermistor must be
reinforced/double insulated.
sc
0.25-22kW
1. Power supply (SMPS)
2. Opto-couplers, communication between AOC and
BOC
3. Custom relays
2
3
The functional galvanic isolation (a on drawing) is for the
RS-485 standard bus interface.
CAUTION
Installation at high altitude:
At altitudes above 2km, please contact Danfoss regarding
PELV.

2.9 Earth Leakage Current

WARNING
DISCHARGE TIME
Touching the electrical parts could be fatal - even after the
equipment has been disconnected from mains.
Also make sure that other voltage inputs have been
disconnected, such as load sharing (linkage of DC
intermediate circuit), as well as the motor connection for
kinetic back-up.
Before touching any electrical parts, wait at least the
amount of time indicated in the Safety Precautions section.
Shorter time is allowed only if indicated on the nameplate
for the specific unit.
®
is a registered Danfoss trademark
SMPS
1
a
M