Introduction
Electrical systems in older commercial buildings can develop unusual wiring issues over time due to the aging of materials, outdated wiring methods, lack of proper maintenance, and changes in usage patterns. As a building owner or facilities manager, it's important to understand common electrical problems in older buildings in order to troubleshoot issues efficiently and prevent more significant failures down the road. In this comprehensive guide, I will cover the typical causes of unusual wiring issues in older commercial buildings and provide actionable tips for troubleshooting and resolving them.
Common Electrical Issues in Older Commercial Buildings
Faulty or Outdated Wiring
Many older buildings still contain old wiring that was installed decades ago using inferior materials or methods that are now outdated. Common problems include:
- Knob and tube wiring - These older systems used insulated wires run through ceramic knobs and tubes. The insulation often breaks down over time.
- Cloth-covered wiring - Early insulated wires had cloth wrapping that can become brittle or deteriorated.
- Aluminum wiring - Used in the 1960s and 70s, aluminum wiring is prone to oxidization and loosening at connections.
- Unsafe splices - Outdated methods like twisting wires together can cause loose connections and shorts.
Lighting Problems
Lighting circuits in older buildings often develop issues like:
- Flickering lights - Sign of a loose neutral wire connection.
- Dimming lights - Can indicate a voltage drop from excessive loads on the circuit.
- Buzzing from lights - Results from vibrating lamp fixtures due to a loose connection.
Faulty Switchgear and Breaker Panels
Switchgear and breaker panels distribute and control power in a building. Age and neglect can lead to:
- Failure to trip - Breakers may not trip as designed due to worn contacts.
- Nuisance tripping - Vibration and loose connections cause unexpected tripping.
- Corroded bus bars - Buildup of oxidation causes overheating.
- Damaged insulation - Insulation breakdown can lead to short circuits.
Grounding and Bonding Issues
A sound grounding system is essential for safety and protecting equipment. Some common grounding issues include:
- Ungrounded electrical systems - Old 2-wire systems without a ground wire are hazardous.
- Open ground connections - Loose or corroded connections defeat grounding effectiveness.
- Poor bonding - Bonding jumpers between metal components may be missing or loose.
Troubleshooting Unusual Electrical Issues
When unusual electrical issues crop up, there are systematic steps you can take to troubleshoot the problem:
1. Talk to Tenants
Speaking directly with tenants experiencing electrical problems can provide important clues. Ask about:
- What type of issue are they seeing? (flickering lights, tripping breakers, etc.)
- When did the problem start? Has it been intermittent or constant?
- Which outlets, lights or equipment are affected?
2. Visual Inspection of Electrical System
Walk through the building and do a visual check of the electrical system, looking for:
- Damage - Cracked switch/outlet covers, damaged wiring insulation.
- Moisture - Signs of water leaks, condensation near electrical components.
- Overloaded Circuits - Excessive devices plugged into outlets, multi-outlet power strips in use.
Pay special attention to problem areas reported by tenants.
3. Check Distribution Equipment
Inspect the breaker panel, fuses and metering equipment:
- Open the panel and check for signs of overheating like discoloration or melted wires.
- Look for corrosion on bus bars or broken breakers.
- Check if the meter shows balanced and expected voltages.
4. Evaluate Grounding and Bonding
Use a multimeter to check for:
- Open ground - Should show 0 volts between neutral/ground.
- GFCI functionality - Test circuit interrupter buttons on GFCI outlets.
- Bonding - Measure continuity between bonded metal components.
5. Check Loads and Circuits
Evaluate circuit loads and wiring:
- Remove excess loads on suspect circuits.
- Check wiring connections are tight with no signs of heat damage.
- Ensure wiring is properly matched to circuit breaker/fuse amperage.
Preventative Maintenance
Along with troubleshooting specific issues, building owners should establish preventative maintenance practices to identify and correct problems before they escalate. Key electrical preventive maintenance steps include:
- Annual inspections by qualified electricians to check wiring, equipment, grounding.
- Load monitoring to avoid overloads.
- IR scanning to identify hot spots in wiring and terminals.
- Testing GFCI outlets monthly.
- Cleaning electrical equipment to prevent dust and corrosion.
When to Call An Electrician
Some electrical problems can indicate potentially hazardous conditions and should be addressed by a certified electrician or electrical contractor. Call an electrician immediately if you experience:
- Repeated breaker tripping
- Sparking, arcing or smoking from outlets
- Buzzing or hot-feeling switch plates
- Shocking sensations from contact with appliances
Aging electrical systems require vigilance to maintain safety and reliability. Following proactive troubleshooting and maintenance practices can help identify and resolve unusual wiring issues in older commercial buildings.