Fused Vs Non Fused Disconnect

There are two types of disconnect switches commonly used in commercial businesses.

Fused vs non fused disconnect.

Currently have a 30 amp fused disconnect mounted on wall next to indoor a h that suddenly partially melted the plastic around the disconnect clip and popped one of the fuses. A non fused disconnect generally has a short circuit withstand of 5000a and a fused disconnect very often has the withstand rating of the fuse that is inserted and approved by the manufacturer resulting in almost always 200k. But none of the non fused disconnects are series rated with circuit breakers. A fused disconnect will also help with certain downstream withstand ratings such as for some transfer switches etc.

Eaton s safety switches continue to be a preferred choice among electrical contractors and end users. So if for example you have an afc of 30ka and you are using 35kaic rated breakers in the panelboard you cannot use a non fused disconnect at the motor starter because it is only going to be rated for 18ka or less without the fuses. When dangerous fluctuations or interruptions are detected your disconnect will as you may expect disconnect power to the tool shutting off access safely before permanent harm or danger can arise. Has aluminum wiring and first tech found in addition to blown fuse one of the line screws very loose.

A full line of general duty heavy duty double throw and hazardous area devices is expanded with a series of innovative new products for a vast variety of applications. Keep in mind that most disconnect switches are fused though some are non fused. It is essentially the difference in function of the two. For example many residences make use of non fusible switches for simple equipment like a water heater.

Let s take a look. With these requirements in mind how do you approach the disconnect switch sizing process. While things that require a higher load often make use of the slightly higher safety ratings of a fusible disconnect switch. He replaced the blown fuse and inserted a replacement disconnect clip and a couple of hours later fuse blew again.

What do we mean by higher safety.