Automation Direct Stellar SR55 Series, Руководство пользователя

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Appendix C: Electromagnetic Compatibility
Page C–5 Stellar
®
SR55 Series Soft Starter User Manual – 1st Ed, Rev F – 09/18/2019
C.7.5 – e
missions
- C
onduCTed
Conducted emissions are able to travel great distances and may cause interference to any
neighboring consumers connected to the common low-voltage supply network.
Allowable levels for conducted emissions generated by semiconductor motor controllers
and starters are influenced by the nature of the low-voltage power distribution network. The
determining factor is whether the source of power is, either:
A) a private supply with a single consumer whose Point of Common Coupling (PCC) is at a
high or medium voltage transformer, or
B) a public low-voltage network with more than one consumer, where the individual PCC is
made directly to the network itself.
The first type of supply (a) is identified as “Industrial”, and requires the use of soft starters
compliant with EN 60947-4-2 Table 19 Environment A Emission Levels.
The second type of supply (b) is identified as “Residential” and requires the use of Class B
equipment. Class B equipment is equipment suitable for use in domestic establishments and
in establishments directly connected to a low-voltage power supply network which supplies
buildings for domestic purposes.
C.7.6 – i
mporTanT
s
ysTems
i
nformaTion
The specification limits for both equipment classes assume systems are grounded at the star
(wye) point of the supply transformer through low impedance connections.
Certain industries, particularly continuous process industries, employ distribution systems
that operate either with a ground connection through a high impedance or without a ground
at all. These systems may cause severe problems of operator safety when installed with
capacitive high frequency filters. Such systems are not considered in this document.
In the case of an isolated or high impedance grounded system, seek advice from your supplier
before fitting a capacitive high frequency filter to an SR55 Soft Starter. It is essential that the
specifying authority, user, or installer has a clear knowledge of the type of network to which
the product is to be installed before making decisions as to which EMC strategy to adopt.
As supplied, all SR55 products comply with the conducted emissions requirements for
environment class A as defined by EN 60947-4-2:2012 Table 19. However, the length and
type of cable connecting the motor to the starter module materially affects the level of
emissions generated, and can amplify them greatly. The standard also allows different levels
of emissions depending on rated input power, which also affects the need to fit filters. The
EN 60947-4-2:2012 standard only requires consideration of steady-state conditions for EMC
emission purposes, and expressly excludes varying conditions such as those during ramp-up
and ramp-down.
Finally, statistics show that the number of disturbances arising from soft starters, operating in
a very wide variety of applications and networks throughout the world, is insignificant. Where
EMC disturbances occur, it is very unlikely that they can be genuinely attributed to a soft
starter.