Electricity Safety Basics

Electrical Control Panels

Electricity is a mystery to many people. Perhaps the most common reason electricity is a mystery is because it is invisible and can only be felt if touched. Something that you can feel and causes pain when touched generally causes fear in many people. At least with a hot stove we can feel the heat as our hand gets closer to the heat source but with electricity there is no warning until the wire is touched and the human body completes the circuit to ground. This causes pain and our natural instinct is to let go of the thing which is causing us pain. Additionally, another common reason electricity is a mystery to many people is that many people do not understand it. A little education about electricity goes a long ways to dissolving the mystery surrounding electricity.

Electricity Safety

Electrical safety is of the utmost importance when we are working around electricity. It is important that you shut down any electrical circuits which you are working on. As a licensed HVAC Master and Journeyman Electrician there are times when I had to work on the equipment while it was operating to solve mechanical and electrical problems with the machine. Extreme care was taken to ensure my safety from electrical shock. I remained hyper-aware of every place I touched and of my balance. Losing your balance and falling into an electrical control panel that has 460 volts can be a life ending experience. Unless you are a professional with many years of experience it is never recommended that anyone work on a live panel. Shut the power off first, lock out the switch so no one comes behind you and restores power to that circuit, and double check the circuit with a volt meter to ensure the circuit has no electricity. Additionally, also remember that some control panels can have more than one power source or the breaker or switch may be mislabeled. This is why it is important to double the circuit and control panel before touching anything inside the panel.

Electrical Accidents

Electrical Disconnect Box

A professional acquaintance was working on a rooftop air conditioning and heating package unit that was supplied by three-phase electrical power. The main electrical disconnect box has the knife blade switching mechanism in it. He threw the switch to the off position and thinking power was disconnected proceeded to open the electrical control panel for the rooftop unit. Throwing caution to the wind thinking power was not on in the unit because he had turned the disconnect switch to the off position, he began working which meant touching some of the wires in the panel. Zap! He got a surprise electrical shock and luckily he was able to pull his hand away. He got in a hurry and did not check the electrical circuit or main electrical power coming into the electrical control panel and he paid for that oversight by being shocked. After further investigation by this acquaintance, he found that one of the knife blades of the three phase power in the electrical disconnect box was stuck in the on position and had broken away from the switching mechanism. This acquaintance was very lucky considering the amount of electricity he was dealing with. 460 volts of electricity can shake you up and make you feel bad for a couple of days, albeit, it is not the voltage that is dangerous to humans but the current. The moral of this electrical accident story is that is always best practice to follow the safety rules to the T. This man was lucky and followed the rule of turning the power off but didn't follow through and double check the electrical circuit with a volt meter. The lesson and moral of the story is to never assume, always check the circuits with a volt meter!