Electrical Installation - Eltek Valere Theia He-t User Manual

4.3. Electrical Installation

Correct electrical connection is critical for achieving a safe, long-term and reliable operation
of the entire PV system.
DANGER: Ensure correct electrical connections!
The electrical connections on the AC and DC side must be performed by qualified
persons and comply with local and national electrical regulations and the
instructions detailed in this User Manual.
Basic PV System Overview
Figure 4.3.1: Simplified PV system overview without DC grounding
4.3.1. Conductors
Two important criteria must be considered in the selection of conductor sizes, namely
ampacity and voltage drop. Using correctly sized conductors improves the efficiency of the
PV system.
• Ampacity refers to the current-carrying capacity of the conductor. The larger the conductor
is, the greater its capacity to carry current.
• Voltage drop is the loss of voltage due to cross section, current flow and length of the
conductor. It is recommended to minimize the system conductor voltage losses, as voltage
losses are equal to loss in energy yield.
CAUTION: Avoid overheating and possible fire!
The conductor cross section area and the disconnector ratings must conform to the
ratings required by local and national electrical regulations.
• Use adequately sized conductors with the correct temperature rating and sunlight resistance.
User Manual THEIA HE-t String Inverters
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357115.013 Issue 1.0, 2011 April
21