Sounds like a minor irritation doesn't it? Just a loose wire, nothing more.... But a loose wire or cable termination can become a serious matter if left unchecked. In fact, a large amount of power loss and electrical fires are caused by something as simple as this.
I'll start with some basics to understand the problem:
1) Electrical cables carry current. The amount of current is proportional to the size of the load you are powering. For example, an LED light fitting will demand much less than a large industrial heater.
2) Heat is produced by electrical current in a circuit. It is a product of current and resistance. Electrical heat is represented in an equation:
H (heat) = I2Rt
'I' = current, 'R' =resistance and 't' =Time
3) Resistance - This component relates to the path of resistance in any circuit conductors, cables and connections and is measured in ohms. As you can see from the above equation, any increase in resistance will proportionately increase the electrical heat produced.
This resistance should be kept as low as possible to prevent any excess heat.
All electrical connections have a resistance across them, and when the cable or wire is terminated correctly and is tightened to the correct torque setting, the resistance across the connection should be negligible.
Problems occur when these connections are not tightened correctly, or terminated with the correct fastenings or lugs, or if the connection becomes loose due to excessive vibration eg in a machinery control panel.
When there is a poor connection, the resistance can become very high and cause excessive heat at the point of connection. If the connection is very poor, arcing can occur which can burn and oxidize the conducting surfaces and cause even further increases to the connection resistance. Basically, any high resistance in a circuit will only become worse over time as the heat causes more damage which causes higher resistances in a damaging feedback loop.
The event is either loss of power in the circuit affected or a fire situation where the heat is transferred from the connection point to surrounding combustible materials. In serious cases such as switchgear and power distribution equipment, the damage can be catastophic and cause explosions with associated significant costs occurred through downtime and equipment replacement.
How can we prevent this from occuring?
There are ways that problems like this can be identified and resolved before any damage is caused. One of the best forms of preventative maintenance for this issue is electrical thermographic imaging.
Thermographic imaging is the survey of your electrical equipment using an infra-red camera to identify points of abnormal temperatures and excessive heat that could lead to power loss or fire.
The inspection is done during normal working hours as all power, lighting, air conditioning and machinery need to be running to identify the issues.
At Solent Power we are an electrical contractor based in Southampton. We are experienced in performing electrical thermographic surveys. Our engineers can identify a range of issues using this technology such as loose connections, overloading, unbalanced loading, incorrect component mounting and induced currents. All of which can lead to business disruption.
Most inspections can be carried out during a single day visit and are done during normal business hours. The survey is non-intrusive so we do not need to isolate your equipment or stop your machinery, thus having no impact on your operations.
Our electrical engineers will identify any issues or causes for concern and this will be detailed with photographs in a full comprehensive report.
We will try to safely resolve any issues during the visit that can be quickly rectified such as loose connections, and we will provide prompt quotations for any required remedial work for your consideration.
Contact us today to find out how we can help your business.
Tel: +44 (0)2381 550 144
Your Power is Our Priority