Technical data

Chapter 2 – Electrical Installation
Siemens Building Technologies, Inc. 131
Chapter 2 - Electrical Installation
EMC-Compatibility
NOTE: The Siemens Building Technologies SED2 Variable Frequency Drives are shipped
without EMC line filters. (The EMC filter is most commonly used in Europe.) Where
local codes or customer/installation requirements dictate, separately orderable line
filters are available. More stringent Class B line filters are also available for most
models. Installation of these filters satisfies the requirements for the EU’s EMC
directive.
Installation
The SED2 operates in environments where they may be exposed to high levels of
electromagnetic interference (EMI). Normally, good installation practices ensure safe and
interference-free operation. However, should problems associated with EMI occur, follow these
guidelines:
• Ensure good electrical contact between the mounting plate and the metal housing of the
SED2 via the mounting screws.
• Use serrated lock washers and electrically conductive mounting plates.
• If a footprint EMC filter is used, fit it under the SED2 and ground it via the metal backplate.
When connecting the EMC filter to the inputs of the SED2, use shielded cables, and ensure
that they are correctly grounded using cable clamps (Figure 2).
Wiring
• Ensure that all equipment in the control cabinet is properly grounded. Connect all equipment
by short, thick grounding conductors to a common grounding point or bus bar.
• Ensure that any control equipment connected to a SED2 (such as PLC or BACS,
programmable logic controller or building automation and control system) connects with a
short, thick cable to the same ground or grounding point as the SED2.
• Use shielded cables inside control cabinets. Use only shielded motor and control cables. The
shielding must be continuous. Connect motor and control cables to ground at both ends.
Avoid pigtails. Use only grounding clamps to bond the shield (Figure 2).
• Lay control, mains, and motor cables separately by routing them in separate cable ducts and
maintaining a minimum clearance of 7.8 inches (200 mm). See Figure 3. If you cannot avoid
crossing cables, run them at a 90-degree angle.
• Motor cables should be as short as possible and should not exceed 82 ft (25 m). Connect the
neutral conductor of all motors controlled by a SED2 drive directly to the ground connection
(PE) of the respective SED2.
• Use ribbon cables, as they have lower impedance at high frequencies.