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Electrical System Optimization
Published in Albert Thumann, D. Paul Mehta, Handbook of Energy Engineering, 2020
Electrical equipment commonly specified is as follows: Switchgear—Breakers—used to distribute power.Unit Substation—used to step down voltage. Consists of a high voltage disconnect switch, transformer and low-voltage breakers. Typical 480-volt transformer sizes are 300 kVA, 500 kVA, 750 kVA, 1000 kVA, 2500 kVA and 3000 kVA.Motor Control Center (MCC)—a structure which houses starters and circuit breakers or fuses for motor control. It consists of the following: Thermal overload relays which guard against motor over loads,Fuse disconnect switches or breakers which protect the cable and motor and can be used as a disconnecting means,Contactors (relays) whose contacts are capable of opening and closing the power source to the motor.
Three-Phase Motor Controls
Published in Don Renner, Hands-On Water/Wastewater Equipment Maintenance, 2017
7.10 The advantage of a motor control center (MCC) is that it provides a single location within a building for all of the controls for the motors. The MCC can be a stand-alone enclosure, or it can be combined with a switchboard style panel (Figure 7.3). The size and style selected for any application will be based on the plant power supply voltage, number of motors involved, secondary power distribution, and available space.
Switchgear, Circuit Breakers, and Motor Control Center
Published in Shoaib Khan, Industrial Power Systems, 2018
A motor control center (MCC) is a modular cabinet system for powering and controlling motors in a factory. Several low-voltage MCCs (fig. 7.14) in a factory may be powered from a main switchgear, which in turn gets its power from a transformer attached to the incoming line from the power company. MCCs are very common sights in factories with heavy machinery, although the purpose they serve is changing.
Methodological and Practical Comparison of Integrated Probabilistic Risk Assessment (I-PRA) with the Existing Fire PRA of Nuclear Power Plants
Published in Nuclear Technology, 2018
Tatsuya Sakurahara, Zahra Mohaghegh, Seyed Reihani, Ernie Kee
In this case study, the fire compartment illustrated in NUREG-1934, Appendix D (Ref. 65), a motor control center panel fire in a switchgear room (Fig. 3), is used as a surrogate fire compartment for the ESF Train A switchgear room at a representative plant. Based on discussions with NPP personnel, the selected fire compartment has similar characteristics to the ESF Train A switchgear room at the representative NPP in terms of the room configuration, ignition source, and damage targets. Two electrical cabinets, one assumed to be a fire ignition source and the other a damage target, are included in the compartment. The initial fire source is modeled by a plate heat source placed on the top surface of the ignition source cabinet, as recommended by NUREG/CR-6850 (Refs. 8 and 12). Three cable trays (“A,” “B,” and “C” in Fig. 3) are installed at different heights below the ceiling and are filled with XLPE insulated cables that have neoprene jackets. The automatic suppression system is not credited, while the failure probability of the automatic fire detectors is assumed to be 0.05; if the automatic detectors work properly, they are assumed to be activated 1 min after the fire ignition.8