3408/3410/3412 Series Industrial PC System Manual
54
Enclosures
The systems are designed to be installed within clean and dry enclosures for both ordi-
nary and hazardous locations. The front panel meets the requirements of UL and CSA
Type 4, 4X, and 12 enclosures. The enclosure used for Class I hazardous locations
should have a minimum rating of Type 12 (NEMA 12, IP 5X). However, Type 4 (IP 6X)
enclosures are strongly recommended.
Panel flatness and rigidity are important to maintain a proper panel seal. If you are going
to use non-metal type enclosures, such as plastic or fiberglass, install a rigid metal stiff-
ener behind the front panel. Failure to do so may result in an inadequate panel seal due to
flexure of the front panel material between the stud mounts. Tighten the nuts on the
mounting studs per the instructions in the previous section, “
Mounting the Unit
.”
Requirements for enclosure fittings, conduit, and wiring vary according to the specific
rating of the location and the type of flammable or combustible material involved. Those
requirements are beyond the scope of this document. It is the customer’s responsibility to
ensure that the installation is compliant with codes and regulations that apply to the spe-
cific location. Reference NFPA 70, Article 500 for specific regulations in the United
States.
Power Switch
The systems do not have a power switch. The amount of input power required by these
systems classifies the power switch as an incendiary device because the voltage and cur-
rent across the make/break device are capable of creating a spark.
Hazardous location regulations state that a power switch rated for ordinary locations may
be used if it is located in a non-hazardous area. However, limits in cable length between
the workstation and the power switch may apply. Otherwise, the switch must be compli-
ant with Class I, Division 1 requirements (intrinsically safe). These switches are built in
a manner that prevents the possibility of a spark when contacts are made or broken.
Use suitable UL-listed and/or CSA-certified Class I, Division 1 switches in hazardous
locations. These switches are available from a number of sources. It is the customer’s re-
sponsibility to ensure that the power switch selected for the installation has the correct
hazardous location rating for the location in which it is installed.
Cable Connections
Division 2 hazardous location regulations require that all cable connections be provided
with adequate strain relief and positive interlock. Never connect or disconnect a cable
while power is applied at either end of the cable.
All communication cables should include a chassis ground shield. This shield should in-
clude both copper braid and aluminum foil. The D-sub style connector housing should be
a metal conductive type (e.g., molded zinc), and the ground shield braid should be well
terminated directly to the connector housing. Do not use a shield drain wire.
