Full Product Manual

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Type 1
SPDs
Type 2
SPDs
Type 3
SPDs
Type 4
SPDs
UL 1449 is Underwriters Laboratories’ safety and performance
standard for surge protection equipment. In 2009, this Standard
was revised to the 3rd Edition. In addition to some nomenclature
changes, there were two very important objectives for revising the
UL 1449 Standard: to harmonize with the International standards
for surge protective equipment (IEC 61643-1) and to modify
performance tests to better simulate real world exposure.
Changes incorporated within UL 1449 3rd Edition provide three significant
enhancements for customers of surge products.
n The first enhancement to the standard is the addition of secondary surge
arresters which are typically mounted outdoors and prior to service entrance
equipment. The addition of surge arresters to UL 1449 ensures that line side
devices (surge arresters) will be manufactured with safety related protection
similar to load side devices.
n The second enhancement includes the addition of a Nominal Discharge Current
Rating (I
N
). The nominal discharge current test allows users to compare a surge
protective device’s durability (or ability to survive a lightning strike) under a UL
regulated test. The UL regulated test provides for a fair and accurate
competitive environment.
n The third change is related to the Voltage Protection Rating (VPR). The past test
was called surge voltage rating (SVR). The requirements of the SVR test were
too weak to exercise many of the surge products in a way that would show how
well they are performing. The new VPR test is performed at 3000 Amps as
opposed to 500 Amps and surge products must show improved performance to
obtain recommended VPR levels of surge protection.
New Descriptive Terminology
Article 285 of the NEC title has been updated to be consistent with UL and IEEE.
The term Transient Voltage Surge Suppressor (TVSS) is being replaced by Surge
Protective Devices (SPDs). The requirements for SPDs were changed and they
are now identified by Type 1, 2, 3, or 4 depending upon where the SPD will be
incorporated within the power distribution system.
Type 1 SPDs: These devices are referred to as a Type 1 SPD due to their location
within the power distribution system. This is typically on the supply side of the
service disconnect overcurrent device (main service panel).
Type 2 SPDs: Typically service entrance SPD panels or branch circuit SPD panels
that are connected on the load side of the service disconnect overcurrent device
(main service panel).
Type 3 SPDs: Typically surge receptacles or cord connected point-of-use devices.
They are permitted to be installed anywhere on the load side of a branch circuit up to
the equipment served, provided the connection is a minimum of 10m (30ft.) from the
service panel. Note: If the distance is less than 10m, a Type 2 SPD (or a Type 3 SPD
tested to Type 2 requirements) must be used.
Type 4 SPDs: Component assemblies consisting of one or more Type 5
components together with a disconnect (integral or external) or a means of
complying with the limited current tests in UL 1449.
Type 5 SPDs: Discrete component surge suppressors connected by its leads or
provided with an enclosure with mounting means and wiring terminations.
UL 1449 3rd Edition: Why is this so important?