Analysis Of Low Voltage Drawer Cabinet Design

Analysis of Low Voltage Drawer Cabinet Design

GCK/GCS/MNS LV Drawers are used for power distribution circuits and are relatively simple. As long as the molded case circuit breaker can be installed, the copper bars of the 630A high current power distribution drawer are easy to arrange. Copper bar connection is equivalent to fixing the plug in one position, which is not conducive to aligning the left and right positions of the contacts and may cause unilateral contact of the plug. Using double clamps can avoid unilateral contact of the plug caused by drawer deviation or additional force on the plug. The old B cabinet uses cable connections and requires multiple sets of plugs. In order to ensure that the drawer does not tilt back, there is also a positioning plug board on the upper part.

For the motor control circuit, the current is generally not high, and using drawers is very convenient for maintenance and repair. Due to the installation of many components such as circuit breakers, contactors, and thermal relays in the motor circuit, it is also necessary to consider the convenience of wiring. Therefore, the size of drawers needs to be carefully considered. A drawer that is too small is not conducive to installing components and heat dissipation, so the design of the drawer needs to be arranged reasonably.

Drawers are very suitable for motor control circuits. Firstly, the current is low and the components are easy to repair and maintain. The 75mm high drawer can be installed 7.5kW@400 /440V direct starting motor control protection.

However, for general domestic circuit breakers, contactors, and thermal relay components, the 6E full mode drawer has a power of 11kW, and the 8E full mode drawer motor has a power of 75kW.

The size of components varies from company to company, so design is required. A new type of small motor protector, with a flat design, featuring flat drawers, 11kW motor drawers, 500mm switchgear, and 75mm high drawer units.

Multi functional low-voltage motor protector, which can realize comprehensive protection of the motor, and can alarm or protect the motor in case of overtime starting, overcurrent, undercurrent, phase failure, locked rotor, short circuit, overvoltage, undervoltage, leakage (grounding), three-phase imbalance, overheating, bearing wear, stator and rotor eccentricity, external fault, automatic starting by incoming power, inverse time limit.

With digital Ammeter and Voltmeter functions, it can display the operating current, voltage and other parameters of A, B and C phases, realize multiple parameter setting functions, fault memory alarm query and action value retention functions, and automatically start and reset when incoming.

For star delta start and forward and reverse start, there are many components, which requires a larger space for installing components and wiring.

Star delta starting is not a true step-down starter because of the full line voltage at the motor terminals. However, during startup, the motor windings are connected in a Y-shaped configuration, which means that there is a wired voltage (i.e. 400V) at both ends of a single winding, but the voltage at both ends of each winding is the square root of the line voltage divided by three (i.e. 230V) or 58%. This will reduce the voltage on the winding, and the motor only draws 33% of the current from the circuit. Due to the voltage on each winding being 58% and the torque being the square of the voltage, the motor output torque is 33%.

The motor is started in both forward and reverse directions, and the forward and reverse directions of the motor are achieved by exchanging phases between two sets of contactors.

There are also designs to install small frequency converters and soft starters in drawers. The frequency converters generate a lot of heat, so the drawers must be large and have a ventilation and heat dissipation design

PRODUCT LINK

http://www.switchgear-china.com/switchgear/low-voltage-switchgear/gcs-electric-distribution-switch-power.html

PRODUCT PHOTO

This product is usually customized.
We are a manufacturer and have a professional technical department that can design and provide solutions according to customer needs.
Please contact our sales personnel to obtain design drawings

Here are our customer examples for your reference

Nepal drawer cabinet

IF NEED MORE DETAILES,PLEASE FEEL FREE YO CONTACT US