Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C-Frame) - ForGe Control - Manual (Page 276)

276 Rockwell Automation Publication 7000L-UM301D-EN-P - June 2014
Chapter 5 Component Definition and Maintenance
Figure 227 - Surge Arresters
Operation
The operation of arresters without a gap is the same as that of MOVs in the TSN.
Depending on design, the arrester may also be gapped. Both gapped and un-
gapped arresters provide adequate overvoltage protection.
The arresters are able to withstand or ride through most commonly seen bus
transients within their capability. However, caution should be taken if there is a
harmonic filter on the MV bus to which PowerFlex 7000 is connected. The filter
should satisfy relevant international or local standards, such as IEEE Std 1531 —
Clause 6.4, to avoid high inrush currents.
The surge arrester is certified as per ANSI/IEEE Std C62.11-1993. Certification
tests include high current short duration tests, low current long duration tests and
fault current withstand tests. The fault current withstand tests consist of different
combinations of kA and number of cycles, including a 20kA 10-cycle test, under
which the arresters are non-fragmenting and without expelling any internal
components.
When the incoming energy exceeds the handling capability of the arrester and
causes arrester failure, the housing is designed to split open to vent without
causing damage to any adjacent components.
U
Heavy duty
distribution
class surge
arrester
W V
Drive input power fro m
line terminals