Fuse Cutouts are used by all electrical utilities around the world today. The fuse cutout protects the distribution Line from over current, by isolation of the fault. It is a convenient and cost effective method of over current protection.
The compact lightweight constructions of LLT silicon fuse cutouts ensure complete ease of Installation. Silicon Insulators offer lightweight solutions to breakage problems that are associated with other insulators such as the porcelain or cycloaliphatic types.
The LLT fuse carrier is designed to accommodate the standard expulsion fuse link and is designed to operate at a maximum of 100A and is used on Distribution networks up to 22kv.
1. The Fuse carrier drops down when the fuse element melts providing positive fault isolation and a clear indication that the cut-out has operated.
2. Installation and removal of the fuse carrier is achieved by the positive engagement of the unit onto a pick up tongue positioned at the hinge end of the expulsion tube. The unit can be operated from ground with the aid of a link stick.
3. The screw cap design at the top end of the fuse carrier provides easy opening and closing of the unit. The spent expulsion link can quickly be replaced with a new unit. The Fuse carrier is lined with an anti-flammable polymer fibre, creating easy venting during high fault current interruptions. The units are often subject to extremely high fault currents and are rated to withstand a current rating of 100A.
4. The Fuse Carrier is designed to accommodate standard expulsion Fuse links of the button head pattern. The button head flanges over the top edge of the carrier, holding it in position. Two speeds of operation are available :- Type K (Fast operating) and Type T (Slow operating).Each with ratings from 1A to 100A.
5. A spring loaded flipper and locking mechanism at the lower end of the fuse carrier ensures consistent tension on the fuse link and prevents element damage during close in. The flipper also assists rapid withdrawal of the fuse link from the tube under low fault conditions.
6. Current transfer is via silver plated contacts and is completely independent of the lower support hinge. The lower contact arrangement ensures positive seating at the hinge point and limits the degree of misalignment during closing. It also assists the initial opening movement of the fuse carrier when operating.
7. The galvanised steel hood protects the top contact assembly from the natural elements and guides the fuse carrier into its insulator and ensures correct latching position during close in. A spring is also situated inside the top hood so that when the fuse carrier is pushed into the unit, it is compressed into position.