Wouldn’t 13,000 volts be the bomb going off compared to the 480?
Or do you mean “a bad shock” as in you die instantly and so you don’t really experience the arc flash?
Shock and arc flash are different hazards that have different causes and risk analysis. They are independent of each other, but you must meet the PPE requirements for both when working within the respective boundaries.
Great question, but nope, 480 is the bomb going off.
If you’re familiar with Ohm’s law then pick a consistent number for power and calculate the current for both voltages.
If you don’t know Ohms law, imagine if you wanted to move the same amount of water as a river moves through a hose, you’d find the water from the hose would fuck you up a lot more than the water from the river. Similar principal with current.
The transformer shown in the picture is likely one of the most dangerous devices in the plant, because it’s taking all that river and shoving it into a hose (turning 13kV into 480v while maintaining the same power). Because of that, the incident energy (explosion size) is at it’s highest at the 480v side of the transformer (current is at its highest).
The only protection (such as a breaker/fuse) upstream of the 480v side of the transformer is on the 13kV side. Imagine the river was shoved into a hose via a water fall. Imagine you wanted to turn the river off because someone was getting blasted with the hose, you’d have to run up a waterfall, which would lower your response time. During which the person getting blasted by the hose would continue to get blasted with the hose.
Transformers almost always have a breaker or fuse directly after it in a circuit, so that it can regulate and respond in a faster way to things such as an arc flash. But the transformer is generally where you see the highest incident energy. That is coming directly from the 480v side. But aside from verifying that the transformer is de-energized there is literally no troubleshooting or manual task that would warrant operating on it live.
Arc flash is not the same as shock. Arc flash is literally an explosion. I’ve been on-site for minor ones that stay contained in the box and just leave smoke and molten metal in the box. And I’ve been there for ones that literally blast the panel front off till it hits a wall - those are the scary ones. Luckily that one no one was nearby it when it blew up. It happened from vibrations moving dust between contacts. The shrapnel would hurt, but even worse is the potential to heat flash the inside of your lungs. That’s why when operating 480v equipment you should take a deep breath first to fill up your lungs, so that you don’t accidentally fill your lungs with hot as fuck air.
However, I would much rather get SHOCKED by 480v over 13,000 volts. But I’d rather not get shocked, so I wear proper gloves for the voltage I’m working on.
Wouldn’t 13,000 volts be the bomb going off compared to the 480?
Or do you mean “a bad shock” as in you die instantly and so you don’t really experience the arc flash?
Shock and arc flash are different hazards that have different causes and risk analysis. They are independent of each other, but you must meet the PPE requirements for both when working within the respective boundaries.
Great question, but nope, 480 is the bomb going off.
If you’re familiar with Ohm’s law then pick a consistent number for power and calculate the current for both voltages.
If you don’t know Ohms law, imagine if you wanted to move the same amount of water as a river moves through a hose, you’d find the water from the hose would fuck you up a lot more than the water from the river. Similar principal with current.
The transformer shown in the picture is likely one of the most dangerous devices in the plant, because it’s taking all that river and shoving it into a hose (turning 13kV into 480v while maintaining the same power). Because of that, the incident energy (explosion size) is at it’s highest at the 480v side of the transformer (current is at its highest).
The only protection (such as a breaker/fuse) upstream of the 480v side of the transformer is on the 13kV side. Imagine the river was shoved into a hose via a water fall. Imagine you wanted to turn the river off because someone was getting blasted with the hose, you’d have to run up a waterfall, which would lower your response time. During which the person getting blasted by the hose would continue to get blasted with the hose.
Transformers almost always have a breaker or fuse directly after it in a circuit, so that it can regulate and respond in a faster way to things such as an arc flash. But the transformer is generally where you see the highest incident energy. That is coming directly from the 480v side. But aside from verifying that the transformer is de-energized there is literally no troubleshooting or manual task that would warrant operating on it live.
Arc flash is not the same as shock. Arc flash is literally an explosion. I’ve been on-site for minor ones that stay contained in the box and just leave smoke and molten metal in the box. And I’ve been there for ones that literally blast the panel front off till it hits a wall - those are the scary ones. Luckily that one no one was nearby it when it blew up. It happened from vibrations moving dust between contacts. The shrapnel would hurt, but even worse is the potential to heat flash the inside of your lungs. That’s why when operating 480v equipment you should take a deep breath first to fill up your lungs, so that you don’t accidentally fill your lungs with hot as fuck air.
However, I would much rather get SHOCKED by 480v over 13,000 volts. But I’d rather not get shocked, so I wear proper gloves for the voltage I’m working on.