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SurgeArrest - minimum install distance of 10 meters (30ft).

Published date: 18 March 2019

Issue:

Why does my Surge Arrest manual indicate the following?


CAUTION: Do not install this device if there is not at least 10 meters (30 feet) or more of wire between the electrical outlet and the electrical service panel.

Product Line:

APC Surge Arrest products

Environment:

Residential use

Cause:

UL1449, 3rd Edition "Standard for Safety for Surge Protective Devices"

Resolution:

There were major revisions made to the UL1449 standard in the mid to late 2000's. Increased safety testing for medium fault current levels, as well as the creation of a single UL standard for all surge protection devices (SPD) were implemented. In September of 2006, Underwriters Laboratories released the revised UL1449, 3rd Edition standard with full industry compliance required by September of 2009. Standard, UL1449 3rd Edition now combines TVSS devices along with surge arresters rated 600v or less, under one certification. The UL1449, 3rd Edition Standard is now broken out into "Type" designations ranging from Type 1-5. 

SPD Type - used to describe the intended application location of the SPD, either upstream or downstream of the main overcurrent protective device of the facility. SPD Types include:

  • Type 1- A permanently connected SPD intended for installation between the secondary of the service transformer and the line side of the service equipment overcurrent device, as well as the load side, including watt-hour meter socket enclosures and Molded Case SPDs intended to be installed without an external overcurrent protective device.

  • Type 2- A permanently connected SPD intended for installation on the load side of the service equipment overcurrent device, including SPDs located at the branch panel and Molded Case SPDs.

  • Type 3- Point of utilization SPDs, installed at a minimum conductor length of 10 meters (30 feet) from the electrical service panel to the point of utilization, for example cord connected, direct plug-in, receptacle type SPDs installed at the utilization equipment being protected. The distance (10 meters) is exclusive of the conductors provided with or used to attach SPDs.

  • Type 4- Component Assemblies -,Component assembly consisting of one or more Type 5 components together with a disconnect (internal or external) or a means of complying with the limited current tests.

  • Type 1, 2, 3 Component Assemblies - Consist of a Type 4 component assembly with internal or external short circuit protection.

  • Type 5 - Discrete component surge suppressors, such as MOVs that may be mounted on a PWB, connected by its leads or provided within an enclosure with mounting means and wring terminations.



UL1449, 3rd Edition now requires that all SPD Types be tested to verify that the average transient voltage surge is limited to the voltage protection rating (VPR) assigned to the SPD. The VPR of an SPD is often referred to as it's "let-through voltage" and is determined during a combination ring wave test conducted at a setting of 6kV / 3kA. This VPR rating is required to be clearly visible on any compliant UL1449, 3rd Edition device.

Type 1 and Type 2 rated surge protection devices are additionally tested to UL96A "Lightning Protection Systems" specifications, as they are at or before the electrical service entrance. Type 3 surge protection devices are subjected to an operating duty cycle test with a combination ring wave at a setting of 6kV / 3kA. This test represents the typical surge encountered at a distance of 10 meters (30ft) from the main electrical service panel. A Type 3 surge protection device is not intended for direct lightning protection, therefore it is tested beyond the potentially effected area.

It is important to note that Type 3 surge protection devices are considered secondary and should be used downstream from the main service panel.

Ideally for residential use, Type 2 which is often referred to as "TVSS" protection should always be installed at the main electrical service entrance.


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