Engineering Information

ROHS INFO

All Enclosures are RoHS compliant.

EMI

Electromagnetic Interference (E.M.I.) is electronic pollution which is caused by rapidly changing voltage. It can cause computational errors or wipe out complete memories, much like electrostatic discharge (E.S.D.), if allowed to penetrate sensitive electronic components. The Serpac E.M.I. enclosure will offer a higher degree of protection than any paired surface. We recommend that all end manufactures conduct open field measurement tests.

IZOD IMPACT TEST

For a part to resist a particular blow without failure two conditions must be met: The part must absorb the total Kinetic energy of the blow, that is, the striker must be brought to zero velocity and then rebound. The stresses developed within the part must not exceed the fracture strength of the material.

FLAMMABILITY OPTIONS

Flammability tests cannot and do not measure material performance in a fire. U.L. standard 94 defines two types of test. These tests lead to essentially six levels of ratings.

Depending on your final use and environment of operation it is likely a U.L. standard will need to be met. Serpac can provide a custom material and certification for your needs.

ABS(MSDS), Polycarbonate, Rubber, Polypropylene, Acetyl, Polyester, KJW (ABS), EMI (ABS), Stat-Kon (Polycarbonate)

The IP Standard

International Standard IEC 60529 outlines an international classification system that describes the sealing characteristics of electrical equipment. The classification system defines the level of protection provided by enclosures to prevent the ingress of foreign objects and moisture into the electrical equipment. The classification system uses the "IP" code, or "Ingress Protection" code, to define the level of seal. The IP code uses a system of two numerical digits to define the level of both foreign object and moisture protection. Although the IP classification is primarily used for establishing the level of seal in electrical equipment, it is adapted herein for determining the level of seal in passive electrical components.

1st Digit, Foreign Bodies - Degrees of Protection

The first digit of the IP code indicates the degree of protection against solid foreign objects from entering the electrical device. The table below outlines the level of protection against foreign objects for each level.

Description of Protection Level

0 = Not protected

1 = Protected against solid foreign objects of 50 mm diameter and greater

2 = Protected against solid foreign objects of 12,5 mm diameter and greater

3 = Protected against solid foreign objects of 2,5 mm diameter and greater

4 = Protected against solid foreign objects of 1,0 mm diameter and greater

5 = Protected from the amount of dust that would interfere with normal operation

6 = Dust tight

2nd Digit, Moisture - Degrees of Protection

The second digit of the IP code indicates the degree of protection against the ingress of various forms of moisture (e.g. drip, spray, submersion, etc.) into the component. Tests to determine the level of protection are carried out with fresh water and do not take into account the use of solvents.

Description of Protection Level

0 = Not protected

1 = Protected against vertically falling water drops

2 = Protected against vertically falling water drops when enclosure is tilted up to 15°

3 = Protected against water sprayed at an angle up to 60° on either side of the vertical

4 = Protected against water splashed against the component from any direction

5 = Protected against water projected in jets from any direction

6 = Protected against water projected in powerful jets from any direction

7 = Protected against temporary immersion in water

8 = Protected against continuous immersion in water, or as specified by the user

NEMA Standard

What does a NEMA 4 rating mean? In non-hazardous locations, there are several different NEMA ratings for specific enclosure "types", their applications, and the environmental conditions they are designed to protect against, when completely and properly installed.. The following provides an overview of the NEMA Types. For complete definitions, descriptions, and test criteria, see the National Electrical Manufacturers Association (NEMA) Standards Publication No. 250.

NEMA 1 - Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment and to provide a degree of protection against falling dirt.

NEMA 2 - Same as NEMA 1 including protection against dripping and light splashing of liquids.

NEMA 3 - Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and that will be undamaged by the external formation of ice on the enclosure.

NEMA 3R - Same as NEMA 3 excluding protection against windblown dust.

NEMA 3S - Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and in which the external mechanism(s) remain operable when ice laden.

NEMA 4 - Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose-directed water; and that will be undamaged by the external formation of ice on the enclosure.

NEMA 4X - Same as NEMA 4 including protection against corrosion.

NEMA 5 - Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against settling airborne dust, lint, fibers, and flyings; and to provide a degree of protection against dripping and light splashing of liquids.

NEMA 6 - Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against hose-directed water and the entry of water during occasional temporary submersion at a limited depth; and that will be undamaged by the external formation of ice on the enclosure.

NEMA 6P - Same as NEMA 6 including protection against the entry of water during prolonged submersion at a limited depth.

NEMA 7 - Enclosures are for indoor use in locations classified as Class I, Groups A, B, C, or D and shall be capable of withstanding the pressures resulting from an internal explosion of specified gases, and contain such an explosion sufficiently that an explosive gas-air mixture existing in the atmosphere surrounding the enclosure will not be ignited. Enclosed heat generating devices shall not cause external surfaces to reach temperatures capable of igniting explosive gas-air mixtures in the surrounding atmosphere. Enclosures shall meet explosion, hydro-static, and temperature design tests.

NEMA 9 - Enclosures are intended for indoor use in locations classified as Class II, Groups E, F, or G, and shall be capable of preventing the entrance of dust. Enclosed heat generating devices shall not cause external surfaces to reach temperatures capable of igniting or discoloring dust on the enclosure or igniting dust-air mixtures in the surrounding atmosphere. Enclosures shall meet dust penetration and temperature design tests, and aging of gaskets (if used).

NEMA 12 - Enclosures constructed (without knockouts) for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against circulating dust, lint, fibers, and flyings; and against dripping and light splashing of liquids.

NEMA 12K - Same as NEMA 12 including enclosures constructed with knockouts.

NEMA 13 - Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against circulating dust, lint, fibers, and flyings; and against the spraying, splashing, and seepage of water, oil, and non-corrosive coolants.

UL flammability information

UL Flame Rating - UL 94 (ratings refers to material properties)

UL flame ratings group materials into categories based on their flammability. UL 94 covers two types of testing: vertical burn and horizontal burn.

Horizontal Testing (HB)

Procedure: A specimen is supported in a horizontal position and is tilted at 45°. A flame is applied to the end of the specimen for 30 seconds or until the flame reaches the 1 inch mark. If the specimen continues to burn after the removal of the flame, the time for the specimen to burn between the 1 and 4 inch marks are recorded. If the specimen stops burning before the flame spreads to the 4 inch mark, the time of combustion and damaged length between the two marks is recorded. Three specimens are tested for each thickness.

Horizontal Flame Test

Horizontal Rating: HB

Requirements:

• Specimens must not have a burning rate greater than 1.5 inches/minute for thicknesses between 0.120 and 0.500 inches and 3 inches/minute for thicknesses less than 0.120 inches.
• Specimens must stop burning before the flame reaches the 4 inch mark.

Vertical Testing (V-0, V-1, V-2)

Procedure: A specimen is supported in a vertical position and a flame is applied to the bottom of the specimen. The flame is applied for ten seconds and then removed until flaming stops at which time the flame is reapplied for another ten seconds and then removed. Two sets of five specimens are tested. The two sets are conditioned under different conditions.

Vertical Flame Test

Vertical Ratings: V-0

Requirements:

• Specimens must not burn with flaming combustion for more than 10 seconds after either test flame application.
• Total flaming combustion time must not exceed 50 seconds for each set of 5 specimens.
• Specimens must not burn with flaming or glowing combustion up to the specimen holding clamp.
• Specimens must not drip flaming particles that ignite the cotton.
• No specimen can have glowing combustion remain for longer than 30 seconds after removal of the test flame.

Vertical Ratings: V-1

Requirements:

• Specimens must not burn with flaming combustion for more than 30 seconds after either test flame application.
• Total flaming combustion time must not exceed 250 seconds for each set of 5 specimens.
• Specimens must not burn with flaming or glowing combustion up to the specimen holding clamp.
• Specimens must not drip flaming particles that ignite the cotton.
• No specimen can have glowing combustion remain for longer than 60 seconds after removal of the test flame.

Vertical Ratings: V-2

Requirements:

• Specimens must not burn with flaming combustion for more than 30 seconds after either test flame application.
• Total flaming combustion time must not exceed 250 seconds for each set of 5 specimens.
• Specimens must not burn with flaming or glowing combustion up to the specimen holding clamp.
• Specimens can drip flaming particles that ignite the cotton.
• No specimen can have glowing combustion remain for longer than 60 seconds after removal of the test flame.

Vertical Testing (5V, 5V-A, 5V-B)

Testing is done on both bar and plaque specimens. Procedure for Bars: A bar specimen is supported in a vertical position and a flame is applied to one of the lower corners of the specimen at a 20° angle. The flame is applied for 5 seconds and is removed for 5 seconds. The flame application and removal is repeated five times. Procedure for Plaques: The procedure for plaques is the same as for bars except that the plaque specimen is mounted horizontally and a flame is applied to the center of the lower surface of the plaque.

Vertical Flame (5V Type) Test

Vertical Rating: 5V

Requirements:

• Specimens must hot have any flaming or glowing combustion for more than 60 seconds after the five flame applications.
• Specimens must not drip.
• Specimens must not be destroyed in the area of the flame.

Vertical Ratings: 5V-A

Requirements:

• Specimens must hot have any flaming or glowing combustion for more than 60 seconds after the five flame applications.
• Specimens must not drip flaming particles that ignite the cotton.
• Plaque specimens must not exhibit burnthrough (a hole).

Vertical Ratings: 5V-B

Requirements:

• Specimens must hot have any flaming or glowing combustion for more than 60 seconds after the five flame applications.
• Specimens must not drip flaming particles that ignite the cotton.
• Plaque specimens may exhibit burn through (a hole).

EMI Shielding

Features

SERPAC enclosures can be customized to shield Electromagnetic Interference (EMI). SERPAC offers two different methods for shielding:

Spray method

Our most common method for custom orders is to spray the interior of the enclosure with a conductive paint. Enclosures can be sprayed with a nickel based paint.

There are no minimum quantities required, but a set-up fee will be applied.

Molded method

The second method for shielding is to mold enclosures in a conductive plastic (black only).

EMI enclosures are available as special order parts.

Orders of a 1000 pieces or more will not incur a setup charge.

Optional End Panels For A-Series, M-Series & H-Series

End Panels are available in Deep Violet for infrared transmission, Clear and Transparent Red.

Clear And Transparent Red
Panel Characteristics

Dielectric Strength: 85 KV/mil

Continuous operating temperature: -50°C (-58°F) to 74°C (165°F)

End Panel Thickness

For all IR, CL & TRANSPARENT

A-Series All A-Series end panels are .0601(1.52) except A-42 which is .125(3.18).

H-Series All H-Series end panels are .045(1.14).

M-Series All M-Series end panels are .065(1.65).

Infrared Panel Characteristics

Dielectric Strength: 380 V/mil

Continuous operating temperature: -129°C (-200°F) to 276°C (310°F)