We will compare short-to-ground vs. short-to-power to determine their similarities and differences in this article.
Two of the most typical electrical issues in circuits are short to ground and short to power.
Although both involve channeling the flow of electricity through an unintended path, they have some differences. Read on to learn more!
What Is Short To Ground?
Short-to-ground refers to a situation where the current flowing in a circuit finds an unplanned path-to-ground.
It happens when a live wire contacts a grounded system area, such as a PCB’s ground plane.
Electrical grounding using a grounding rod
The fault will drain most of the current through this point, so the components won’t get enough electricity to work with.
To put it into perspective, think of water flowing through a pipe. A short-to-ground is equivalent to a big hole along the line that drains most of the water.
The excessive current flow can blow fuses or trip circuit breakers. And when it flows, this current can cause electrical shock if you touch the ground path.
In the worst-case scenario, the current flow can cause burns and fires.
What Is Short To Power?
The wire harnesses or conductive traces in compact circuits like PCBs can contact other circuit parts.
If these parts are not ground paths, the current will flow to areas other unintended areas.
This contact will heat the area, causing burns or fires. And like shorting to ground, this connection can also cause electric shocks.
But the critical difference is this shorting usually does not drain a lot of current from the intended path.
Damaged circuit breakers causing short circuit fires
Let’s consider the voltage across a circuit to be 100V in normal conditions. If you measure the voltage using a digital multimeter, it will be lower if there is a short circuit.
Using Ohm’s law, V=IR, there will be a voltage drop when the resistance decreases due to the access to an unintended path.
The drop will be smaller with shorting to power because resistance will reduce by a small margin. So you might get a reading of about 60V.
However, shorting-to-ground reduces the resistance drastically, although it won’t get to zero due to ground resistance. So you might get a reading of about 5-10V.
What About Dead Shorts
Dead shorts emerge when circuit currents flow out via an unintended path with zero impedance or resistance.
So it is a more severe version of short-to-ground due to its lower resistance connection.
It usually occurs when current flows to the neutral or negative terminal via direct electrical connections.
This situation directs all the power through the direct link to the negative/neutral terminal.
So you’ll get a 0V reading when measuring the voltage across the components in this circuit.
But there is a thin line between dead shorts and short to ground.
Short To Ground vs. Short To Power: Causes
Ground faults or short-to-ground usually occur due to these causes.
- Water leaking into the circuit or electrical box (water conducts electricity and can create a ground connection)
- Loose or worn hot wires that come into contact with ground wires
- Wires without proper insulation due to stripping too far or chewing by bugs/rodents
- Debris in receptacle boxes
- Not using GFCI outlets or GFCI-protected extension cables when working below grade level or outdoors
A tripped GFCI outlet
On the other hand, short to power or short circuits occur due to the following.
- Internal wiring faults that cause live and neutral wires to touch
- Conductor insulation damage or insulation faults (wearing out between two wires)
- Loose connections or incorrect wiring on two wires in junction boxes
- Wire slipping out of a terminal, then contacting another wire
A short circuit caused by a positive and negative wire touching
Short To Ground vs. Short To Power: Consequences
Short-to-ground and short-to-power faults have similar consequences, which include the following.
Electrical shocks are more common if there is water in the equation. However, they can also occur due to wire insulations wearing out.
An electrician experiencing electrical shock
Shorting increases the current flow, which generates more heat. So the surrounding parts become hot and can burn the skin if touched unknowingly.
The heat can ignite the PCB or insulators if the current flow is high. This situation usually occurs if the circuit has no fuse or circuit breaker, allowing the current to flow for a long time uninterrupted.
A fire on a PCB caused by short-circuiting
Short To Ground vs. Short To Power: Protection and Preventive Measures
The preventive measures for these two faults vary slightly. To prevent short to ground, do the following.
- Test ground fault equipment
- Use overcurrent protection devices like GFCI outlets or GFCI-protected extension cables.
- Install circuit breakers in the circuit
- Do visual checks to detect and repair worn wire insulation
A row of circuit breakers
With short-circuiting, use these preventive and protective measures.
- Update power outlets that are over 15 years old.
- Install circuit breakers and AFCIs (Arc-Fault Circuit Interrupters) in the electrical system
- Do regular maintenance on these protective devices
Ground faults and short circuits have minimal differences that primarily arise from these two factors: the leakage path and the amount of current flowing out.
Short-to-ground leaks more current via the ground path, while short-to-power leaks minimal current to other unintended areas in the circuit.
And the best way to stop these current leaks before they become dangerous is to use overcurrent protection devices.
That’s it for this article. Don’t forget to share your thoughts and sentiments in the comments below.