User manual

AC Adjustable Frequency Drives
Important Safety and Product Information
164
Abridged Description of NEMA Enclosure
Test Requirements
controlled so as to cause ice to build up at a rate of 1/4 in (6.4
mm) per hour until 3/4 in (19 mm) thick ice has formed on top
surface of a 1 in (25.4 mm) diameter metal test bar, then
temperature is maintained at –23 °F (–5 °C) for 3 hours.
Evaluation 6.6.2.2: Equipment shall be undamaged after ice has
melted (external mechanisms not required to be operable while
ice-laden).
6.7 Hosedown Test — Enclosure and external mechanisms are
subjected to a stream of water at 65 gallons (246 liters) per minute
from a 1 in (25.4 mm) diameter nozzle, directed at all joints from
all angles from a distance of 10 to 12 ft (3 to 3.7 meters). Test
time is 48 seconds times the test length (height + width + depth of
enclosure in ft) (meters), or a minimum of 5 seconds. No water
shall enter enclosure.
6.8 Rust Resistance Test (Applicable Only to Enclosures
Incorporating External Ferrous Parts) — Enclosure is
subjected to a salt spray (fog) for 24 hours, using water with five
parts by weight of salt (NaCI), at 95 °F (35 °C), then rinsed and
dried. There shall be no rust except where protection is impractical
(e.g., machined mating surfaces, sliding surfaces of hinges, shafts,
etc.).
6.9 Corrosion Protection — Sheet steel enclosures are evaluated
per Underwriter’s Laboratories (UL) 50, Part 13 (test for
equivalent protection as G-90 commercial zinc coated sheet steel).
Other materials per Underwriter’s Laboratories (UL) 508, 6.9 or
6.10.
6.11 (2) Air Pressure Test (Alternate Method) — Enclosure is
submerged in water at a pressure equal to water depth of 6 ft (2
meters), for 24 hours. No water shall enter enclosure.
6.12 Oil Exclusion Test — Enclosure is subjected to a stream of
test liquid for 30 minutes from a 3/8 in (9.5 mm) diameter nozzle
at 2 gallons (7.57 liters) a minute. Water with 0.1% wetting agent
is directed from all angles from a distance of 12 to 18 in (305 to
457 mm), while any externally operated device is operated at 30
operations per minute. No test liquid shall enter the enclosure.
6.2 Rod Entry Test — A 1/8 in (3.18 mm) diameter rod must not
be able to enter enclosure except at locations where nearest live
part is more than 4 in (102 mm) from an opening — such opening
shall not permit a 1/2 in (13 mm) diameter rod to enter.
6.3 Drip Test — Water is dripped onto enclosure for 30 minutes
from an overhead pan having uniformly spaced spouts, one every
20 sq in (12900 mm
2
) of pan area, each spout having a drip rate of
20 drops per minute. Evaluation 6.3.2.2: No water shall have
entered enclosure.
6.4 Rain Test — Entire top and all exposed sides are sprayed with
water at a pressure of 5 psi (0.35 kg/cm
2
) from nozzles for one
hour at a rate to cause water to rise 18 in (457 mm) in a straight-
sided pan beneath the enclosure. Evaluation 6.4.2.1: No water
shall have reached live parts, insulation or mechanisms.
Evaluation 6.4.2.2: No water shall have entered enclosure.
6.5.1.1 (2) Outdoor Dust Test (Alternate Method) — Enclosure
and external mechanisms are subjected to a stream of water at 45
gallons (170.5 liters) per minute from a 1 in (25.4 mm) diameter
nozzle, directed at all joints from all angles from a distance of 10
to 12 feet (3 to 3.7 meters). Test time is 48 seconds times the test
length (height + width + depth of enclosure in feet), or a minimum
of 5 minutes. No water shall enter enclosure.
6.5.1.2 (2) Indoor Dust Test (Alternate Method) — Atomized
water at a pressure of 30 psi (2.11 kg/cm
2
) is sprayed on all seams,
joints and external operating mechanisms from a distance of 12 to
15 in (305 to 381mm) at a rate of 3 gallons (11 liters) per hour. No
less than 5 ozs (142 gms) of water per linear foot of test length
(height + length + depth of enclosure) is applied. No water shall
enter enclosure.
6.6 External Icing Test — Water is sprayed on enclosure for one
hour in a cold room 35.6 °F (+2 °C); then room temperature is
lowered to approximately –23 °F (–5 °C) and water spray is
Enclosure Selection Criteria, Continued
For a Degree of Protection Against
Atmospheres Typically Containing: ‡
Designed to Meet
Tests 7
Class (National
Electrical Code)
Type
7, Class I Group 9, Class II Group
ABCDEFG
Acetylene
Explosion,
Hydrostatic and
Temperature Test
I
9
Hydrogen, Manufactured Gas I
99
Diethyl Ether, Ethylene, Hydrogen Sulfide I
9
Acetone, Butane, Gasoline, Propane, Toluene I
99
Metal dusts and other combustible dusts with resistivity of
less than 10
5
ohm-cm.
Dust Penetration Test
Temperature Test with
Dust Blanket
II
9
Carbon black, charcoal, coal or coke dusts with resistivity
between 10
2
…10
8
ohm-cm
II
9
Combustible dusts with resistivity of 10
5
ohm-cm or greater II
9
Fibers, flyings § III
9
✶ For indoor locations only unless cataloged with additional NEMA Type enclosure number(s) suitable for outdoor use as shown in table on page Important-9.
Some control devices (if so listed in the catalog) are suitable for Division 2 hazardous location use in enclosures for non-hazardous locations. For explanation
of CLASSES, DIVISIONS and GROUPS, refer to the National Electrical Code.
Note: Classifications of hazardous locations are subject to the approval of the authority having jurisdiction. Refer to the National Electrical Code.
7 See abridged description of test requirements below. For complete requirements, refer to UL Standard 698, compliance with which is required by NEMA
enclosure standards.
‡ For listing of additional materials and information noting the properties of liquids, gases and solids, refer to NFPA 497M-1991, Classification of Gases,
Vapors, and Dusts for Electrical Equipment in Hazardous (Classified) Locations.
§ UL 698 does not include test requirements for Class III. Products that meet Class II, Group G requirements are acceptable for Class III.