China
Africa
Explore chapters and articles related to this topic
Branch Circuits and Feeders
Published in Moncef Krarti, Energy-Efficient Electrical Systems for Buildings, 2017
The ampacity is often used as a term to refer to the amount of current that a conductor can carry continuously without exceeding its temperature ratings under normal conditions of utilization. Several parameters affect the continuous rating of conductors including their physical characteristics such as insulation level and cross-sectional area as well as their surrounding environment such as ambient air temperature. Table 6.1 lists the ampacities of various insulated conductors with rated voltage ranging between 0 and 2000 V (NEC, 2014).
Arrangement Optimization of Power Cables in Harmonic Currents to Achieve the Maximum Ampacity Using ICA
Published in Electric Power Components and Systems, 2018
Masoumeh Rasoulpoor, Mohammad Mirzaie, Seyyed Mehdi Mirimani
An important step in the computation of power cables ampacity is determination of the generated heat. Resistive losses of metallic parts of the cables are the main heat sources. So, the accurate calculation of the losses is necessary for power cable ampacity analysis. Also, current distributions in parallel cables are non-uniform. The sub-conductors method is used for determining the currents, resistances, and losses with consideration of skin and proximity effects. This method is based on the division of conductors and sheaths to very small conductors (elements) without the skin or proximity effects. Where, the impedance of the elements is computed by Carson formula [5, 17]. Sheaths of the cable system are earthed at both sides. The electrical relation between the conductors, sheaths, and ground return path currents is as: where Iji, (j = R, S, T), IE and Np are conductor current and sheath current of ith parallel cable in j phase, earth current, and the number of parallel cables in each phase, respectively. Using the mesh method, each loop in the electrical system is represented by a sub-conductor related to the main phase conductor or sheath and the ground return path. The relevant matrix equation can be written as:
Impact of Wiring Resistance on PV Array Configurations in Harvesting the Maximum Power Under Static and Dynamic Shading Conditions
Published in IETE Journal of Research, 2022
Kandipati Rajani, Tejavathu Ramesh
KYOCERA-KC200GT PV module of size 1.425 m × 0.99 m has been considered for PV array. The continuous arrangement has been taken for modules in a column as shown in Figure 3(a). The Isc of each PV module is 8.21 A and hence in a column to connect the modules in series, the wire must have an ampacity of 1.56 × Isc = 12.8 A as per National Electrical Code (NEC) [48]. For the ampacity of 12.8 A, 16 American Wire Gauge (AWG) wires have to be used and the resistance per km wire length is 13.2 ohms. Wire covering the length of one module has a resistance R = 0.0132 × 1.425 = 0.0187 ohms.
A comprehensive investigation of a solar array with wire length under partial shading conditions
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Vijay Laxmi Mishra, Yogesh K. Chauhan, K.S. Verma
Several solar modules are connected with the help of wires to generate electricity from them. During the reconfiguration process, more wires are needed because the modules are physically relocated. This study incorporates a polycrystalline solar module SYN-10W rating. The size of the wire for solar module connections is decided by its current carrying ability. Thus, as per the National Electrical Code (NEC) wire should have the ampacity of 1.56. So, a 12 American Wire Gauge (AWG) is chosen for this purpose (Wiles 2001).