Enclosure Types - Danfoss VLT AutomationDrive FC 300 Design Manual

Safety and Conformity

2.4 Enclosure Types

The VLT Series adjustable frequency drives are available
in various enclosure types to best accommodate the
needs of the application. Enclosure ratings are provided
based on two international standards:
•
NEMA (National Electrical Manufacturers
Association) in the United States
•
IP (International Protection) ratings outlined by
IEC (International Electrotechnical Commission) in
the rest of the world
Standard Danfoss VLT adjustable frequency drives are
available in various enclosure types to meet the
requirements of IP00 (chassis), IP20, IP21 (NEMA 1), or IP54
(NEMA12).
UL and NEMA Standards
NEMA/UL Type 1 – Enclosures constructed for indoor use
to provide a degree of protection to personnel against
incidental contact with the enclosed units and to provide a
degree of protection against falling dirt.
NEMA/UL Type 12 – General purpose enclosures are
intended for use indoors to protect the enclosed units
against the following contaminants:
•
fibers
•
lint
•
dust and dirt
•
light splashing
•
seepage
•
dripping and external condensation of non-
corrosive liquids
There can be no holes through the enclosure and no
conduit knockouts or conduit openings, except when used
with oil-resistant gaskets to mount oil-tight or dust-tight
mechanisms. Doors are also provided with oil-resistant
gaskets. In addition, enclosures for combination controllers
have hinged doors, which swing horizontally and require a
tool to open.
UL type validates that the enclosures meet NEMA
standards. The construction and testing requirements for
enclosures are provided in NEMA Standards Publication
250-2003 and UL 50, Eleventh Edition.
MG34S222
Design Guide
IP Codes
Table 2.4 provides a cross-reference between the two
standards. Table 2.3 demonstrates how to read the IP
number code and defines the levels of protection. The
adjustable frequency drives meet the requirements of
both.
Table 2.3 IP Number Cross Reference
First digit (solid foreign objects)
0
1
2
3
4
5
6
Second digit (water)
0
1
2
3
4
5
6
7
8
Table 2.4 IP Number Code Definitions
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
NEMA type
Chassis
Protected chassis
NEMA 1
NEMA 12
No protection
Protected to 50 mm (hands)
Protected to 12.5 mm (fingers)
Protected to 2.5 mm (tools)
Protected to 1.0 mm (wire)
Protected against dust – limited entry
Protected totally against dust
No protection
Protected from vertical dripping water
Protected from dripping water at 15° angle
Protected from water at 60° angle
Protected from splashing water
Protected from water jets
Protected from strong water jets
Protected from temporary immersion
Protected from permanent immersion
2
IP type
IP00
IP20
IP21
IP54
17
2