Chapter 3-Installation
3-33
Enclosures
The systems are designed for installation within a clean and dry enclosure for both
ordinary 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.
Warning
The optional floppy disk/keyboard port access door must be closed and
latched at all times in order to maintain a proper seal against the
intrusion of water and dust.
Panel flatness and rigidity are important if a proper panel seal is to be maintained. If
non-metal type enclosures, such as plastic or fiberglass, are to be used, install a rigid
metal stiffener 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 to 25-inch pounds.
The 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 and it is the
responsibility of the customer to ensure that their installation is compliant with codes
and regulations that apply to their specific location. Reference NFPA 70, Article 500
for specific regulations in the United States.
Power Switch
The 3510/3512 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 current across the make/break device are capable of creating
a spark.
Hazardous locations' regulations require that a power switch rated for ordinary
locations may be used if it is located in an area specified as non-hazardous.
However, limits in cable length between the workstation and the power switch may
apply. Otherwise the switch must be compliant 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 wide number of sources. It
is the responsibility of the customer to ensure that the power switch selected for their
installation has the correct hazardous locations rating for the location in which it is
installed.
