Is a Copper Busbar Better Than Aluminum?

When assembling electrical control panels, switchgear, and industrial power distribution systems, the busbar is a critical backbone carrying large currents within tight tolerances. For this core application, spec’ing the right busbar material matters greatly. Copper has long been the industry standard, but is aluminum gaining ground as a lower-cost alternative? 

Aluminum Busbar vs Copper Busbar – Key Differences

Let’s examine the pros and cons of different types of busbars.

Electrical Conductivity

On a fundamental level, copper has an edge due to its higher conductivity compared to aluminum. As current density rises in busbars, resistance heating becomes more problematic – and copper generates less waste energy through I2R losses.

For applications involving frequent overload conditions or variable load profiles, copper’s superior heat dissipation maintains cooler operating temperatures that prolong component life. However, enhanced aluminum alloys have narrowed the gap, bringing conductivity about halfway between aluminum and copper.

Mechanical Durability

Copper also endures mechanical stresses like vibration and thermal cycling better than softer aluminum over the long haul. Its work-hardening characteristics generate a protective oxide patina providing self-healing corrosion resistance indoors. But modern alloys give aluminum overlapping outdoor durability when properly treated and welded.

Material Cost Analysis

While copper outperforms electrically and mechanically, aluminum has a compelling attribute – cost. On a pound-for-pound basis, high-purity aluminum sells for approximately one-third less than copper. Considering multi-ton bus systems, savings stack up fast when downsizing materials.

However, a true value assessment should factor for total cost of ownership over the years. Copper’s reliability may allow longer service periods before replacement compared to aluminum under heavy loading. Reputation for quality also builds confidence in continuous rated systems.

Favorable prices could shift the equation for lower-risk, intermittent duty applications less demanding than process control. But critical infrastructure merits premium materials maximizing uptime over decades. Overall material savings sometimes fail to outweigh costs from unplanned outages.

Design Considerations

Beyond raw material debates, bus design heavily impacts busbar performance. Contact resistance between sections matters greatly for both materials. Proper joint preparation and torque of mechanical connections drops voltage drops immensely compared to soldering.

Correct sizing minimizes constriction at strap-to-bar interfaces too. Oversizing aluminum relative to flexible copper busbar further improves temperature matching. Skin-effect decreases resistance toward surfaces for either metal, so increasing bar thickness moderately helps large currents.

Proper ventilation shelters busbars from elevated ambient temperatures as well. On/off loads induce transient heating even in copper, so spaced ventilation cuts peak heating cycles. Paired with de-rating for ambient conditions, optimal design often equals or surpasses simple material switches.

In Summary

When carefully engineered, both copper and aluminum serve busbars commendably, with trade offs considered. Copper remains the first choice for applications requiring ultra-long-life and tolerance of severe overload exposures. But upgraded aluminum alloys compete well on initial outlay, suiting moderately loaded, intermittent systems. Overall performance stems more from design best practices applied judiciously to material qualities.

To get the top quality busbar for your facility, partner up with TOSUNLux – one of the best copper busbar suppliers – today.