Refer to the nameplate shown in the example. The largest fuse you could install in a fused safety switch is ___ A.

• A. 60
• B. 80
• C. 70
• D. 50

Answer: (C)

In a fused safety switch, the fuse size is limited by the switch’s own protection rating, which is shown on the nameplate. The nameplate tells you the maximum fuse size that the device is designed to accommodate. Installing a fuse larger than that would override the switch’s protection and could create unsafe conditions if a fault occurs. In the example, the nameplate specifies 70 A as the maximum fuse size, so the largest fuse you could install is 70 amperes. Using a smaller fuse is possible but may lead to nuisance blows, while a larger fuse would exceed the switch’s protective rating and is not allowed.