What Causes Burning Smells From LV Switchgear in Commercial Buildings?

 A burning smell coming from LV switchgear is often an early warning sign of overheating, loose electrical connections, overloaded circuits, insulation failure, or internal component damage.

Ignoring these smells can lead to:

• Electrical fires

• Arc flash incidents

• Equipment failure

• Operational downtime

Common causes include:

• Loose busbar connections

• Faulty breakers

• Overloaded systems

• Dust contamination

• Ageing electrical components

Commercial buildings operating complex LV switchgear and power distribution systems should treat burning smells as a serious fault indicator and arrange inspection immediately.

Why Burning Smells From Switchgear Should Never Be Ignored

A burning smell near electrical switchgear is rarely harmless. In most cases, it indicates that excessive heat is developing somewhere within the electrical distribution system.

The smell often comes from:

• Overheated insulation

• Burning cable coatings

• Damaged electrical components

• Arcing within switchgear assemblies

Even if power remains operational, the underlying issue may continue worsening behind the panel.

Facilities managers responsible for commercial LV switchgear systems should treat unusual electrical odours as an urgent warning sign.

Loose Electrical Connections

Loose electrical connections are one of the most common causes of burning smells in LV switchgear.

When connections loosen over time:

• Electrical resistance increases

• Heat builds up at connection points

• Insulation begins degrading

This overheating often produces a distinctive burning or hot plastic smell before visible damage appears.

Common areas affected include:

• Busbar joints

• Cable terminations

• Breaker connections

Routine inspection of LV switchgear infrastructure helps identify loose connections before serious failure occurs.

Overloaded Electrical Circuits

Switchgear designed years ago may no longer match the electrical demand of modern commercial buildings.

As equipment loads increase, overloaded circuits generate excessive heat inside switchboards.

This heat can:

• Damage insulation

• Stress breakers

• Produce burning odours

• Reduce equipment lifespan

Signs of overload may include:

• Frequent breaker trips

• Warm switchgear panels

• Flickering power supply

Buildings experiencing increased demand should review their LV switchgear and electrical distribution systems to ensure systems remain correctly rated.

Faulty Circuit Breakers

Circuit breakers can deteriorate over time due to:

• Mechanical wear

• Heat stress

• Repeated operation

• Internal arcing

A failing breaker may overheat internally and produce a burning smell even before it trips.

Older switchgear systems are particularly vulnerable to breaker degradation.

Regular maintenance of commercial switchgear systems helps identify failing protective devices early.

Insulation Breakdown

Electrical insulation prevents current from escaping conductors and contacting other components.

Over time, insulation can degrade due to:

• Heat

• Moisture

• Ageing

• Contamination

As insulation breaks down, overheating and arcing become more likely.

Burning insulation often creates a strong acrid smell near switchgear panels.

Ageing low voltage switchgear installations should be inspected regularly to identify insulation deterioration.

Dust and Contamination Inside Switchgear

Dust buildup inside electrical panels is a major risk factor in commercial and industrial environments.

Contamination can:

• Restrict ventilation

• Trap heat

• Increase electrical resistance

• Contribute to arcing faults

When heat builds up around dust and debris, burning smells can develop rapidly.

Routine cleaning of LV switchgear assemblies helps reduce contamination-related risks.

Overheating Busbars

Busbars distribute electrical current throughout switchgear systems.

If busbar joints loosen or become overloaded, temperatures can rise significantly.

Overheating busbars may produce:

• Burning smells

• Discolouration

• Visible scorching

• Arcing damage

Thermal imaging is commonly used to identify overheating busbar connections before failure occurs.

Poor Ventilation in Electrical Rooms

LV switchgear generates heat during normal operation and relies on adequate airflow to dissipate temperature safely.

Poor ventilation can lead to:

• Heat accumulation

• Component overheating

• Reduced equipment lifespan

Electrical rooms with restricted airflow are more likely to develop overheating issues within LV switchgear systems.

Why Burning Smells Often Appear Before Failure

One of the biggest dangers with switchgear faults is that burning smells often appear before catastrophic failure occurs.

This early warning stage provides an opportunity to:

• Investigate faults

• Prevent downtime

• Reduce fire risk

• Avoid equipment damage

Ignoring the smell and repeatedly resetting breakers can allow the problem to escalate.

How Engineers Diagnose Burning Smells in Switchgear

Proper investigation typically includes:

• Visual inspection

• Thermal imaging surveys

• Load analysis

• Electrical testing

• Inspection of breakers and busbars

Thermal imaging is particularly effective because it identifies overheating components before visible damage becomes severe.

Commercial facilities operating complex LV switchgear distribution systems should ensure all findings are documented and reviewed.

How to Prevent Burning Smells in LV Switchgear

Preventative maintenance is the most effective way to reduce overheating risks.

Recommended actions include:

• Routine inspections

• Tightening electrical connections

• Thermal imaging surveys

• Cleaning switchgear cabinets

• Reviewing electrical loads

• Replacing ageing components

A proactive maintenance strategy helps ensure switchgear remains safe, compliant, and reliable.

Frequently Asked Questions

Is a burning smell from switchgear dangerous?

Yes. Burning smells often indicate overheating or electrical faults that can lead to fire or equipment failure.

What causes electrical panels to smell like burning plastic?

This is usually caused by overheating insulation, loose connections, or overloaded components.

Can overloaded circuits cause burning smells?

Yes. Excessive electrical load generates heat which can damage insulation and produce odours.

Should I turn off switchgear if I smell burning?

If safe to do so, the issue should be isolated and investigated immediately by qualified professionals.

Can dust inside switchgear cause burning smells?

Yes. Dust buildup traps heat and increases overheating risk.

Do loose busbar connections smell before failing?

Often yes. Loose connections commonly produce heat and burning odours before visible failure occurs.

How do engineers find overheating switchgear faults?

Thermal imaging surveys are one of the most effective diagnostic tools for identifying overheating components.

Can ageing switchgear cause burning smells?

Yes. Older components and degraded insulation are more likely to overheat.

Is thermal imaging necessary for switchgear maintenance?

It is strongly recommended because it identifies hidden overheating issues early.

Can preventative maintenance stop switchgear overheating?

Yes. Regular inspection and servicing significantly reduce the risk of overheating and electrical failure.