High voltage is electrical potential big enough to cause damage. For industries, high voltage is voltage above a certain threshold. Equipment and conductors with high voltage warrant special safety procedures.
Low voltage is lower voltage, often powers small devices (electronic devices or appliances) and less dangerous. But, it can't power large devices as good as high voltage.
A low voltage release (LVR) is a circuit's system that automatically restart if voltage restores upon dip or power loss. If voltage drops below a threshold, the circuit opens (stops operation).
When voltage returns to normal, the circuit automatically re-energizes without manual intervention.
Common uses:
Refrigeration systems, HVAC controls, and pumps where continuous operation is needed.
Motor starters must resume operation after a power failure.
A high voltage protection (LVP) is the system ensuring a circuit won't automatically reenergize upon power restoration after power outage, needed if sudden power application load may cause injury.
Common uses:
Industrial machinery, safety systems, and equipment with potential hazardous unintended restarting.
For electrical codes in some high-risk applications.
How to tell if a circuit uses LVP or LVR:
Check the control circuit wiring:
LVR: Uses a maintained-contact control (e.g., a relay stays near if power returns).
LVP: Uses a momentary-contact control (e.g., a start-stop station needing manual reset).
Test the system:
Simulate a voltage drop (using a variable transformer).
If the system restarts automatically = LVR.
If it stays off until manually reset = LVP.
Review schematic/manual:
Look for labels like "LVR" (auto-restart) or "LVP" (manual reset).
Check if the circuit relies on a three-wire control (LVP) or two-wire control (LVR).
Examine the starter/contactor:
Magnetic motor starters often have LVP by default (unless modified).
Some devices have adjustable settings for LVR/LVP modes.
Low voltage is ~0-50 V.
High voltage is ~1k-500k V. Note which electricity type is used as they can both be dangerous in many ways. E.g. low voltage is more likely to cause shocks and high voltage can cause severe burns.
Low and high voltage are 2 main electrical cables and equipment types:.
Low voltage is often for automotive, marine, aircraft applications, as well as telecommunications, audio/video, security systems, and household appliances, like hairdryers and vacuum cleaners.
High voltage is for power generation, transmission, distribution applications, or electrical equipment, like motors, generators, transformers, and medical applications, like X-ray and MRI machines.
As high voltage is dangeroushave proper safety measures in place to work with it.
Low and high voltage is the intensity electricity is sent into wires. Low voltage is less likely to damage, while high voltage is more dangerous. While low voltage is generally safe, some safety measures should still be taken.
E.g. Working via low voltage electrical wires, ensure wires aren't damaged/exposed. High voltage electrical wires are more dangerous, so extra care is when. To ensure they aren't damaged/exposed, wear protective clothing and avoid coming in contact to them.
High voltage is more expensive to produce than low voltage.
But the cost of low- and high-voltage cables can vary depending on the length and thickness of the cable. Low voltage cables are typically less expensive than high voltage cables, but they can't carry as much power. High voltage cables are usually more expensive and have much more energy. The cost of installation can also vary depending on the type of cable.
Low voltage cables are typically easier to install than high voltage cables and therefore cost less.
Low voltage systems are often deemed safe but can still be a shock risk if not handled rightly. High voltage systems is worse and must be treated with high caution, causing hazards and arcs if not done correctly.
Arcing is a hazard occuring as electrical current jumps from a conductor to another, due to gaps in electrical path/when the voltage is too high for a system, causing fires/explosions.