Chapter 2: Installation and Wiring
2–7
DL205 Installation and I/O Manual, 2nd Edition
5. The ground terminal on the DL205 base must be connected to a single point ground. Use copper
stranded wire to achieve a low impedance. Copper eye lugs should be crimped and soldered to the
ends of the stranded wire to ensure good surface contact. Remove anodized finishes and use copper
lugs and star washers at termination points. A general rule is to achieve a 0.1 ohm of DC resistance
between the DL205 base and the single point ground.
6. There must be a single point ground (i.e. copper bus bar) for all devices in the panel requiring an
earth ground return. The single point of ground must be connected to the panel ground
termination. The panel ground termination must be connected to earth ground. For this
connection you should use #12 AWG stranded copper wire as a minimum. Minimum wire sizes,
color coding, and general safety practices should comply with appropriate electrical codes and
standards for your region. A good common ground reference (Earth ground) is essential for proper
operation of the DL205. There are several methods of providing an adequate common ground
reference, including:
a) Installing a ground rod as close to the panel as possible.
b) Connection to incoming power system ground.
7. Properly evaluate any installations where the ambient temperature may approach the lower or
upper limits of the specifications. Place a temperature probe in the panel, close the door and
operate the system until the ambient temperature has stabilized. If the ambient temperature is not
within the operating specification for the DL205 system, measures such as installing a
cooling/heating source must be taken to get the ambient temperature within the DL205 operating
specifications.
8. Device mounting bolts and ground braid termination bolts should be #10 copper bolts or
equivalent. Tapped holes instead of nut–bolt arrangements should be used whenever possible. To
ensure good contact on termination areas impediments such as paint, coating or corrosion should
be removed in the area of contact.
9. The DL205 system is designed to be powered by 110/220 VAC, 24 VDC, or 125 VDC normally
available throughout an industrial environment. Electrical power in some areas where the PLCs are
installed is not always stable and storms can cause power surges. Due to this, powerline filters are
recommended for protecting the DL205 PLCs from power surges and EMI/RFI noise. The
Automation Powerline Filter, for use with 120 VAC and 240 VAC, 1–5 Amps, is an excellent
choice (can be located at www.automationdirect.com), however, you can use a filter of your choice.
These units install easily between the power source and the PLC.
Enclosures
Selection of a proper enclosure is important to ensure safe and proper operation of your
DL205 system. Applications of DL205 systems vary and may require additional features. The
minimum considerations for enclosures include:
• Conformance to electrical standards
• Protection from the elements in an industrial environment
• Common ground reference
• Maintenance of specified ambient temperature
• Access to equipment
• Security or restricted access
• Sufficient space for proper installation and maintenance of equipment
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