Loose Contacts- The bane of all electrical systems

Loose contact or loose connection is by far the biggest cause of fire hazards and electrical failures . An in-depth understanding of causes, effects and prevention will go a long way in protecting our appliances and enhancing electrical safety .

Loose contact is caused due to loose wires, loose plug or loose screws in LV System . In MV/HV systems , loose lug, bolt, male-female contacts cause loose contact .

Most of the loose contacts go unnoticed as most of the users are unaware of the initial signs . These signs can be like local hotspots, discolouration of wiring or plugs etc . In most of the systems, no maintenance is carried out till electrical failure arises .

Periodic maintenance carried out can very easily detect these signs and corrective action can be taken . One of the simple methods is measurement of contact resistance . This is done by injecting DC current which will provide a result in microohms . Any higher result indicates loose contact .

Another method is thermal scanning  as shown above . This is can very easily detect hotspots and loose contact .

Loose contact can cause multiple problems like :

1) Spark between cable and equipment

2) Damage of Cable Lugs.

3) Insulation failure due to overheating .

Most of the fire hazards can be eliminated if periodic checks for loose contact are carried out.