A time delay fuse is a special kind of fuse that allows electrical surge for a short time before it actually blows. Due to its special design, it can bear electricity overload in a repeated cycle for a short period without blowing.Click to see full answer. Simply so, what is a delay fuse? Purpose of a Time Delay Fuse A time-delay fuse is also sometimes known as a slow blow fuse. The purpose of this type of fuse is to allow a surge in electricity for a short time before the fuse actually blows. However, it’s beneficial and actually much safer for certain types of electrical appliances.Also Know, do time delay fuses go bad? Yes indeed, fuses do expire from old age. Yes, fuses can get tired, but its equally possible you have an intermittent problem with the switch or perhaps the starting capacitor (assuming its not 3ph). First replace the fuse and see if you get lucky, then diagnose further if needed. Also, how are fast acting fuses different than time delay fuses? Unlike the time-delay version, it does not have the capacity to withstand temporary overloads. It gives a quick response to electric spikes and then protects the devices by breaking the circuit.How can you tell if a screw fuse is blown?In some cases you may need a small screwdriver to unscrew the fuse holder cap. Look at the fuse wire. If there is a visible gap in the wire or a dark or metallic smear inside the glass then the fuse is blown and needs to be replaced. If you cannot see whether the fuse is blown, follow steps 4 and 5.