By Jeson Pitt | Electrician | D&F Liquidators
An electric fuse is an important electrical component that protects against overcurrent events by melting its elements and opening the circuit. Fuses must be applied at or below their specified voltage rating, which differs between ac and dc current.
They come in different shapes and sizes. This allows you to pick a replacement easily, however, since there is such a wide variety available, the likelihood of two aesthetically identical fuses having the same operating specifications is pretty low. Due to this, one can make mistakes while selecting a new or replacement fuse. This mistake may put people and equipment at risk.
You must make the right choice of fuse. Understand different types of fuses and their uses so that you can make better choices. You need to consider the following factors:
You can choose from different kinds of fuse types such as time-delay fuse for inductive loads or fast-acting fuses for resistive loads. You must determine what your control circuit requires and pick a fuse type based on that. This ensures in providing the right kind of protection. Consider the material of fuse wire as well while making a selection.
Next, verify what the required voltage rating is. It must be equal to or greater than the circuit voltage for the proper application of an over-current protective device. The device can have a higher rating, however, it should not have a lower one because when an overcurrent protective device is applied beyond its rating, there may be potential for fire and arcing energy, which poses a severe fire risk to other components in the panel. You must know the voltages that will be across the electrical fuse box as it will help you buy a properly rated fuse.
Confirm that the interrupting rating of the selected fuse wire is sufficient for the circuit application. The interrupting rating must be equal to or greater than the available short-circuit current. It is critical that the overcurrent protective device is able to safely interrupt the short-circuit currents to which the equipment is subjected.
If the fault current exceeds a level beyond the capacity of the protective device, then the device may rupture, thus causing additional damage. This is why you must opt for a fuse that is capable of sustaining the largest potential short-circuit currents. Failure to apply fuses with the appropriate interrupting rating can be a serious safety hazard.
Short-circuit Current Ratings
You can easily carry out circuit protect calculations with the help of available compliance software which helps calculate short-circuit current rating (SCCR) based on the components used in an electrical panel. The software will guide you through the process of entering the electrical panel’s components and then calculates an assembly SCCR, providing the needed documentation.
Other selection factors that you need to consider include the start-up (inrush) currents and transient load conditions. The inrush current can have a significant effect on the fuse’s life, which is why the size of the fuse must properly to allow the inrush current pulses to pass without nuisance openings or degrading the fuse element.
You should also calculate current pulse energy by determining the magnitude and duration of the current pulse. The most accurate way to determine parameters of a current pulse is by measuring this current in the application under minimum and maximum voltage conditions. The pulse factor depends on the construction of the fuse element.
It is absolutely critical that you opt for the right fuse for controlling the circuit protection. It will keep your home and loved ones safe from any kind of electrical accidents.
Jeson Pitt works with the marketing department of D&F Liquidators and regularly writes to share his knowledge while enlightening people about electrical products and solving their electrical dilemmas. He’s got the industry insights that you can count on along with years of experience in the field. Jeson lives in Hayward, CA and loves to explore different cuisines that the food trucks in the Bay area have to offer.