Product Brochure

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www.leviton.com/industrial
SURGE PROTECTIVE DEVICES
Type 3 clamp level
Type 2 clamp level
Type 1 clamp level
47277-007
55208-ASA
S2000
How To Implement An Effective Surge Protection Network
SURGE
PROTECTIVE
DEVICE
PERFORMANCE
TYPE 1
Typically mounted on the
line side of the main service
entrance. Protects against
external surges caused by
lightning or utility capacitor
bank switching.
TYPE 2
Typically serves a branch
circuit and protects against
residual lightning energy,
motor driven surges and other
internally generated surges.
TYPE 3
Typically used at the protected
equipment. Provides point-of-use
protection, easily replaceable and
it provides the last line of defense
against a lightning strike.
Standardization
The SPD Types (Type 1, 2, 3, 4) are the UL, NEC and IEEE
attempt to harmonize with the IEC 61643-1 standard that
uses Class 1, 2, 3 designators. The sole reason that UL
did not use Class 1, 2 and 3 is that North, Central & South
America lean towards the IEEE documents , which use an
8 x 20µs surge waveform instead of the 10x350µs surge
waveform, as it more accurately reflects the conditions
experienced during a lightning strike. Since the test is
different, the name had to be different.
The drawing to the right identifies category A, B and C
as defined in the IEEE Trilogy of Standards. Category C
ranges from the transformer secondary to just inside the
building entrance. Category B includes all of the branch or
sub-panels and Category A includes the receptacles and
point-of-use devices such as cord-connected or plug-in
surge devices.
Note: There is purposeful overlap between the categories
as it is not a demarcation line but a transition. The
figure to the right is from IEEE C62.41.2 which is the
Recommended Practice on Characterization of Surges in
Low-Voltage (1000V and Less) AC Power Circuits.
Service
Equipment
Service
Equipment
A B C
Service
Entrance
Service
Entrance
Meter
Underground Service
Outbuilding
Subpanel
XF
Service
Equipment
Service
Equipment
Service
Entrance
Service
Entrance
Meter
Underground Service
Outbuilding
Subpanel
Service
Equipment
Service
Equipment
A B C
Service
Entrance
Service
Entrance
Meter
Underground Service
Outbuilding
Subpanel
XF
In order to achieve optimum protection for your equipment, it is essential to utilize a
distributed approach to surge suppression. That is, you’ll need to install surge protective
devices (SPDs) that knock down high-energy transients at the building entrance and/or
sub-panel so that they’re manageable for the smaller SPDs that protect PCs and other
equipment at point-of-use. Leviton offers a comprehensive selection of devices that will
allow you to implement the most effective surge protection network possible.
Surge Protection Network