ALUMINUM WIRING
Aluminum wiring in residential installations: Issues with aluminium wiring
Purchasers or owners of homes built from the mid 1960’s until the late 1970’s may have aluminum wiring while some homes may have a mixture of aluminum and copper wiring.
Reported problems with aluminum wiring have been related to the overheating and failure of aluminum wiring terminations.
This is due to aluminums tendency to oxidize and its incompatibility with devices designed for use with copper wiring. Warm cover plates or discolouration of switches or receptacles, flickering lights, or the smell of hot plastic insulation may be evidence of these problems.
Each home will be different and must be assessed on its own. It is highly recommended the homeowner hire a licensed electrical contractor who is knowledgeable in the special techniques required for working with and repairing aluminum wiring. The contractor should do an assessment, make the necessary repairs, and have the work inspected by ESA (Electrical Safety Authorities).
The homeowner should obtain a copy of the Certificate of Inspection for their records and for their insurance company (if requested).
NOTE:
Some insurance companies and or insurance brokers may request removal off all aluminum wiring of a resale property. It is recommend a home buyer verify with their insurer as to policy coverage.
As mentioned above, where problems exist with aluminum wiring they are usually found at termination points. This necessitates the opening of all outlets (receptacles, switches, fixtures, appliance connections, and in the (panel board) and visually inspecting terminations for signs of failure and overheating without removing or disturbing the devices or wiring.
There should be no signs of overheating such as darkened or discoloured connections, melted insulation, etc.
Where problems are found the damaged aluminum conductor should be cut back to remove the damaged portion and then the necessary repairs made.
Required markings for switches, receptacles and other device ensure they are compatible with aluminum wiring.
General inspection
Question:
If ESA completes a general inspection, does the OESC (Ontario Electrical Safety Code) require an older house that is wired with aluminum wiring to have all non-CU/AL devices replaced with devices approved for connection to aluminum wiring, or have copper tails installed at each connection point.
Answer:
No, If the devices are the original ones installed and show no visible signs of overheating or other damage, then they are not required to be replaced (it is recommended only). If a device shows any visible signs of overheating or other damage, then replacement is required. If any of the devices have been replaced in the past with newer devices (ie: Decora style), then they are not original and are required to be replaced with a Code compliant installation.
Rationale:
Rule 2-300 of the OESC (Ontario Electrical Safety Code) requires that operating electrical equipment be kept in safe and proper working condition and that defective equipment shall either be put in good order or permanently disconnected. Where there is no evidence of deterioration of the wire, the termination, or the device, then the Code does not require that repairs be made.
Myths
Aluminum wiring itself is safe and if proper connections and terminations are made without damaging the wire and using approved materials installed in accordance with the Ontario Electrical Safety Code and the manufacturer’s instructions, there should be no problems with the aluminum wiring installation
Information obtained from Electrical Safety Authority
Purchasers or owners of homes built from the mid 1960’s until the late 1970’s may have aluminum wiring while some homes may have a mixture of aluminum and copper wiring.
Reported problems with aluminum wiring have been related to the overheating and failure of aluminum wiring terminations.
This is due to aluminums tendency to oxidize and its incompatibility with devices designed for use with copper wiring. Warm cover plates or discolouration of switches or receptacles, flickering lights, or the smell of hot plastic insulation may be evidence of these problems.
Each home will be different and must be assessed on its own. It is highly recommended the homeowner hire a licensed electrical contractor who is knowledgeable in the special techniques required for working with and repairing aluminum wiring. The contractor should do an assessment, make the necessary repairs, and have the work inspected by ESA (Electrical Safety Authorities).
The homeowner should obtain a copy of the Certificate of Inspection for their records and for their insurance company (if requested).
NOTE:
Some insurance companies and or insurance brokers may request removal off all aluminum wiring of a resale property. It is recommend a home buyer verify with their insurer as to policy coverage.
As mentioned above, where problems exist with aluminum wiring they are usually found at termination points. This necessitates the opening of all outlets (receptacles, switches, fixtures, appliance connections, and in the (panel board) and visually inspecting terminations for signs of failure and overheating without removing or disturbing the devices or wiring.
There should be no signs of overheating such as darkened or discoloured connections, melted insulation, etc.
Where problems are found the damaged aluminum conductor should be cut back to remove the damaged portion and then the necessary repairs made.
Required markings for switches, receptacles and other device ensure they are compatible with aluminum wiring.
- Receptacle rated at 20 amps or less must be marked “CO/ALR” or “AL–CU”
- Receptacle rated for greater than 20 amps must be marked “AL–CU” Or “CU–AL”
- Switch rated at 20 amps or less must be marked “CO/ALR”
- Wire Connectors intended for use with combinations of either an aluminum conductors or copper conductors and or both must be marked “AL–CU” Or “CU–AL”
General inspection
Question:
If ESA completes a general inspection, does the OESC (Ontario Electrical Safety Code) require an older house that is wired with aluminum wiring to have all non-CU/AL devices replaced with devices approved for connection to aluminum wiring, or have copper tails installed at each connection point.
Answer:
No, If the devices are the original ones installed and show no visible signs of overheating or other damage, then they are not required to be replaced (it is recommended only). If a device shows any visible signs of overheating or other damage, then replacement is required. If any of the devices have been replaced in the past with newer devices (ie: Decora style), then they are not original and are required to be replaced with a Code compliant installation.
Rationale:
Rule 2-300 of the OESC (Ontario Electrical Safety Code) requires that operating electrical equipment be kept in safe and proper working condition and that defective equipment shall either be put in good order or permanently disconnected. Where there is no evidence of deterioration of the wire, the termination, or the device, then the Code does not require that repairs be made.
Myths
- Aluminum wiring was recalled because it is known to be a fire hazard.
- Aluminum wiring is no longer used for interior wiring systems.
- The Ontario Electrical Safety Code permits the installation of aluminum wiring.
- Adequate precautions shall be given to the terminations and splicing of aluminum conductors;
- Aluminum wiring itself is safe if proper connections and terminations are made, without damaging the wire and devices approved for use with aluminum wire are employed.
- Aluminum wiring is widely used today for larger commercial and industrial feeders.
- Electrical distribution companies use it widely throughout their distribution systems including the supply service cable to most residences; in fact it may still be used today for interior wiring systems in residential homes as well as other structures.
Aluminum wiring itself is safe and if proper connections and terminations are made without damaging the wire and using approved materials installed in accordance with the Ontario Electrical Safety Code and the manufacturer’s instructions, there should be no problems with the aluminum wiring installation
Information obtained from Electrical Safety Authority