Images depicted herein are for demonstration purposes. Each facility is different, and user needs may vary. Adjust accordingly, based on equipment value and/or downtime expenses.
IEEE C62.41.2-2002 Category C
IEEE: Category C - Service Entrance
Exposure
NEC 285 & NRTL: SPD Type 1, 2, or
equivalent Type 4
N&G Bonded (i.e., L-N and L-G are
same)
(Per Phase generally considered Sum
of L-N plus L-G)
Gen Set
Load Side
Surge Current kA ratings for
all Categories are subjective.
Consult SPD mfg for specific
recommendations
IEEE C62.41.2-2002 Category B
ATS / STS
Type 1 or 2
SPD
Load side of the Switch
protects Service and Gen Set
Distribution
Indoor
HVAC
(VFD)
Distribution
Type 1 or
2 SPD
Type 1 or 2
SPD
Type 1 or
2 SPD
MCC
Indoor
L-N and L-G are different – need L-N,
L-G, and N-G
(Per Phase generally considered Sum
of L-N plus L-G)
UL 96A Lightning
Protection System
SPDs at Service
Entrances require
20kA I-n and UL Mark
Type 1 or 2
SPD
NEC 285 & NRTL: SPD Type 1, 2, or
equivalent Type 4
Historical kA Ratings:
Per Phase: 300kA to 100kA per phase
Per Mode: 150kA to 50kA per mode
ANSI/UL 1449 - Surge Protective Devices
UL 1283 – EMI/RFI Filtering
ANSI/IEEE C62.41.1-2002 – Guide on Surge
Environment
ANSI/IEEE C62.41.2-2002 – Characterization
of Surges
ANSI/IEEE C62.45-2002 - Testing
IEEE C62.62-2010 - Testing
IEEE C62.72-2007 – Application Guide
Service Entrance
IEEE: Category B - External remnant
or Internally Induced
Require appropriate SCCR ratings
Relevant SPD Standards (1000V and Less):
Line Side
Higher available fault currents require
appropriate SCCR ratings
Historical kA ratings:
Per Phase: 400kA to 200kA per phase
Per Mode: 200kA to 100kA per mode
Line side requires
Type 1 SPD per
NEC 285 & UL 1449
Type 1
SPD
Equipment installed outside of the
building could increase exposure
level to Category C. Consider
effects of Ground Potential Rises
from direct lightning strikes to earth
Wind or PV
Generation
Type 1 or
2 SPD
Outdoor
Type 1 or
2 SPD
Busway
Outdoor
Lighting
Type 1 or
2 SPD
Outdoor
HVAC
(VFD)
Type 1 or 2
SPD
Type 1 or
2 SPD
Type 1 or
2 SPD
Protect both ends of the
bus way against reflections
Establishes a new reference to ground, like a
service entrance. L-N only may be sufficient
IEEE: Category A, maybe B, maybe C if
outdoor loads are connected
IEEE C62.41.2-2002 Category A
Branch
Type 3
SPD
Branch
NEC 285 & NRTL: SPD Type 1, 2, or
equivalent Type 4. Could be Type3.
L-N and L-G are different – need L-N,
L-G, and N-G
“Pre”
SPD
(Type 1)
Indoor
Lighting
Type 1 or
2 SPD
Separately Derived System
Small or Office
Equipment
Type 1 or
2 SPD
Branch
Require appropriate SCCR ratings
Historical kA Ratings;
Per Phase: 160kA to 100kA per phase
Per Mode: 80kA to 50kA per mode
UPS
(or PDU, PDM)
Type 1 or
2 SPD
Computers or
Servers
Revision Date: April 14, 2014
Branch
Outdoor
“Post”
SPD
(Per Phase generally considered Sum
of L-N plus L-G)
Type 1 or
2 SPD
Indoor
Outdoor
Lighting
Type 1 or
2 SPD
Outdoor
Equipment
Type 1
or 2 SPD
Equipment installed outside of the building could increase
exposure level to Category C. Consider effects of Ground
Potential Rises from direct lightning strikes to earth
Equipment
Type 1 or
2 SPD
Series
SPD
Equipment
Series or two-port SPDs may disconnect
downstream loads at end of life