On a plug-in light set, the fuses are in a small holder in the plug, or near it. Unplug the set, open the holder and replace the blown fuse with one of the spares that came with the set, at the rating marked for it, such as 3 A, 125 V.
What happened?
Look at the plug’s two flat blades. Is one wider than the other?
Start overWhat to do
Throw the set away
When a replacement fuse blows as well, the set may have a short circuit.
See also
Start overWhat to do
At least one fuse, in or near the plug
A light set with a polarized plug, one blade wider than the other, has at least one fuse.
See also
Start overWhat to do
Two fuses, in or near the plug
A light set whose plug blades are the same width has two fuses.
See also
Start overUnplug the set, and any sets connected to it, before you open the fuse holder.
If the new fuse blows too, throw the set away.
Opening and closing the holder
- On GE’s mini sets, the fuse cover is on top of the plug and slides toward the blades. A flathead screwdriver opens it.
- Close the cover all the way afterward, so the fuses are fully covered.
- Before you plug the set back in, check that the connected sets don’t add up to more watts than the tag allows. See how many light strings you can connect.
Throw out any set with broken or cracked sockets, frayed or bare wires, or loose connections.
3 A or 5 A
Use the rating marked on your set or given in its instructions. GE’s mini sets take a 3 amp, 125 volt fuse, and Holiday Living’s clear C9 set a 5 amp, 125 volt fuse.
The 1997 edition of UL 588, the safety standard for light sets, tied the fuse to the wire size: 3 A on 22 AWG wire, and 5 A on 20 and 18 AWG.
Why fuses blow
A blown fuse means an overload or a short circuit. GE’s instructions give too many sets connected end to end as the most common cause.