Electrical basics.

Many years ago a friend who worked on generators gave me an analogy that I have used many times since to explain how electricity works. I will offer it now, hoping it to be a reference point for future troubleshooting tips and of some educational value.

Think of water and a hose.

The pressure is the voltage and the amount of water flowing is the amperage. Remember these terms.

Let’s say the spigot is on and the nozzle is shut off. You will have full pressure but no flow. Voltage but no amperage.

Now let’s crack the nozzle a bit. Now we have a flow, amperage. And pressure, voltage.

Let’s say we turn the nozzle full on. The pressure (voltage) may drop because the amount of water flowing (amperage) exceeds the ability to sustain such pressure.

Let’s say we just crack the spigot a bit. But the nozzle is off. We will get enough flow to build up full pressure, but when we open the nozzle, even a moderate amount, that point (the spigot which is barely cracked on) will restrict the flow (amperage) and you will see the pressure drop.

Both voltage and amperage are essential data for both troubleshooting and system design. Something as simple as an inverter or any other electricity consuming device (toaster, etc) requires a given amount of “flow”. Insufficient paths will cause, in the case of electricity, heating up and even burning of circuits, as well as component failure. Most electrical fires are not caused by “shorts”, as every circuit has a capacity and a fuse or breaker which matches the wire size, which will blow in the event of a short (a short is basically a pathway that doesn’t go through the device, but through a “shorter” pathway- like when two wires rub together and make a circuit), but rather are caused by weak connections. The “flow” isn’t too high for the circuit design (presuming it was engineered properly), but the circuit has a “weak point”, like a kink in a hose.

I can’t count the number of times I’ve fixed weak connections that were caused by human error and could have been avoided by a simple “tug” to assure a tight connection.

In future posts I will discuss how to engineer a circuit to perform its task properly.

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