Selection Guidance of Copper Bar in Low Voltage Switchgear Cabinet

1. Purpose

Specification of copper bars used in switchgear cabinets is to select appropriate cross-section specifications when designing copper bars to ensure the rated carrying capacity of copper bars in the corresponding operating environment.


2. Scope of application

All electrical copper and copper busbar bending tool alloy buses.


3. Operational Guidance for Selection of Copper Bar in Low Voltage Switchgear Cabinet

3.1 Normal Use Conditions of Copper Bar in Low Voltage Switchgear Cabinet

Copper row material: TMY and THMY which conform to GB/T5585.1-2005 standard;

Usage conditions: ambient temperature 35 C, allowable temperature rise 70 K;

Altitude: < 1000m;

Rated operating frequency: 50/60Hz.

In case of inconsistency with the above conditions, the carrying capacity of the copper bars shall be re-checked according to the specific conditions of the copper bars according to Article 4 of this Guideline.


3.2 Selection of Horizontal Main Busbar  in System

Under normal operating conditions, technical support engineers select or modify the specifications of the horizontal bus according to the rated current of the low voltage system in Table 1. If the design institute does not agree to the modification, the technical support engineer must work with the mechanical design engineer to confirm the specification selection of the horizontal main bus.

Table 1: Rated ampacity meter for horizontal bare copper busbar (copper row stand-up, single-phase spacing a = 110, double-phase a = 110, triple-phase a = 130)