UL 1449 Rev 03262015, Surge Protective Devices

Additions to existing requirements are underlined

A nonmetallic enclosure shall comply with the applicable mechanical/electrical property considerations, flammability and thermal requirements for non-attended, non-intermittent duty portable equipment as specified in the Standard for Polymeric Materials– Use in Electrical Equipment Evaluations, UL 746C.

Additions to existing requirements are underlined

The flexible cord shall be Type S, SO, ST, SJ, STO, SJO, SJT, SJTO or shall be a type at least as serviceable for the particular application. Outdoor use products shall include ²W² suffix.
 

Additions to existing requirements are underlined

The length of a supply cord measured from the outside surface of the enclosure of a SPD to the plane of the face of the attachment plug shall not be less than 0.45 m (1.5 ft) or be more than 7.6 m (25ft.).

Exception No. 1: SPDs with only one or two receptacles are not required to comply with the minimum supply cord length.

Additions to existing requirements are underlined

A sample of the SPD is to be tested for leakage current starting with the as-received condition – as received being without prior energization except as may occur as part of the production-line testing – but with its grounding conductor circuit open at the test receptacle. An SPD intended for outdoor use shall additionally be subjected to the leakage current test following a 48 hour humidity conditioning of air having a relative humidity of 88 ±2 percent at a temperature of 32 ±2°C (90 ±4°F). Immediately following the humidity conditioning, the sample is to be removed from the humidity chamber and tested as noted below. The supply voltage is to be adjusted to:

a) 120 V for an SPD rated between 110 and 120 V;

b) 240 V for an SPD rated between 220 and 240 V; and

c) The rated voltage marked on the SPD for any other voltage.

The test sequence with reference to the appropriate measuring circuit is to be as follows:

d) For single-phase SPDs,

1) Using the appropriate circuit from Figure 37.1and, with switch S1 open, the SPD is to be connected to the measuring circuit. Leakage current is to be measured using both positions of switch S2.

2) Switch S1 is then to be closed energizing the SPD and, within a period of 5 seconds, the leakage current is to be measured using both positions of switch S2.

3) The leakage current is to be monitored until the leakage current stabilizes or decreases. Both positions of switch S2 are to be used in determining this measurement.

e) For three-phase SPD, the measurements are to be made when the leakage current has stabilized using Figure 37.2, with each of the switches SA, SB and SC open in turn and the other two switches closed. The SPD enclosure or other dead metal parts intended to be grounded are not to be connected to ground, except through the measuring circuit during the test.

New table added;

Low-temperature steel sphere impact test – Temperature Conditioning Requirements

Additions to existing requirements are underlined

A Type 3 SPD shall be marked ²To Reduce the Risk of Electric Shock – Use only Indoors² or the equivalent. A Type 1 or Type 2 SPD shall be marked ²NEMA Type 1 Enclosure² and may be additionally marked ²Indoor Use Only². The marking shall be either on the inside or outside surface but shall be visible after installation. Lettering shall not be less than 2.4 mm (3/32 inch) high.

Exception No. 1: An SPD that employs other than a Type 1 enclosure as specified in 7.1.1.2 shall comply with the type designation marking requirements, for Enclosure Types, in the Standard for Electrical Equipment, Environmental Considerations, UL 50E.

Additions to existing requirements are underlined

An instruction manual or the equivalent shall be provided, shall only reference those applications that have been evaluated, and shall include the following:

a) Instructions for installation: Instructions for permanently wired devices shall include the wire gauge sizes, the ampacity of the circuit the device is intended for use on, and the internal wiring methods showing location and routing. The instructions shall state: “The conductors used to connect the SPD to the line or bus and to ground shall not be any longer than necessary and shall avoid unnecessary bends” or similar wording.

b) Instructions for mounting.

c) An explanation of the purpose and function of any indicator (lights, audio indicators, and similar indicators) features employed on the SPD.

d) The interrupting rating of any required external circuit breaker or the short-circuit current level of any required external fuse.

e) The following statement shall be required for SPDs intended for use on ungrounded power systems: ²Caution – Ungrounded power systems are inherently unstable and can produce excessively high line-to-ground voltages during certain fault conditions. During these fault conditions any electrical equipment, including an SPD, may be subjected to voltages which exceed their designed ratings. This information is being provided to the user so that an informed decision can be made before installing any electrical equipment on an ungrounded

power system.²

f) A rack-mounted cord-connected Type 3 SPD shall be provided with instructions for mounting within portable and/or stationary equipment, as applicable.