The Electric Fuse is the small, cheap looking part that opens almost every keycard puzzle in Rust. You drop it into a fuse box at a monument, flip a switch, and for a short window the card reader on the security door has power. Without a fuse the reader stays dead, your keycard does nothing, and the loot room stays shut.
That makes the fuse one of the most important items to carry on a monument run, even though it only takes one inventory slot. This fuse Rust guide covers what the Electric Fuse does, how to use it step by step, every monument that needs one and how many, the best places to loot fuses, how much scrap they recycle for, and how the Electric Fuse differs from the newer Heavy Fuse.
- What It Is
- Stats
- How to Use a Fuse
- Monuments That Need a Fuse
- Where to Find Fuses
- Recycle Value
- Electric vs Heavy Fuse
- Fuse Budget for a Card Run
- Tips
- FAQ
What Is the Electric Fuse in Rust?
The in-game description says it all: “An unreliable electric fuse. Will allow electrical passthrough for a period of time.” It is a component, but unlike gears or metal pipes you never use it in a recipe. Its only job is to sit in a monument fuse box and carry power to the puzzle for a short time.
Fuses arrived with the monument puzzle update in June 2018, together with keycards, security doors, switches and fuse boxes. The system has barely changed since. Every keycard door needs power, and at most monuments that power comes from a fuse. Once the fuse is in and the switch is on, the card reader lights up, you swipe, and the door opens.
You cannot use the Electric Fuse in your own base. Fuse boxes only exist at monuments, and base power runs on player electricity (wind turbines, solar panels, batteries and wires) instead. The bigger Heavy Fuse from the Power Trip update is a separate item for the Power Plant grid and does not open puzzles.
Electric Fuse Stats
| Stat | Electric Fuse |
|---|---|
| Shortname / Item ID | fuse / -629028935 |
| Category | Component |
| Rarity | Rare |
| Craftable | No (no blueprint, not researchable, not on the tech tree) |
| Bought from | No vendor sells it, loot only |
| Stack size | 10 |
| Despawn time | 40 minutes on the ground |
| Used in | Monument fuse boxes for keycard puzzles |
| How long it works | A short window, then it blows and disappears |
| Best source | Tech Parts crate, 26.5% for 1 to 2 |
| Recycles into | 24 scrap at a powered monument recycler (16 in a safe zone) |
Stack size, despawn time, rarity and the recycle value come straight from the current game item files. The ID is also in our Rust item IDs list if you run a server and want to spawn fuses with admin commands (inventory.give fuse 10).
How to Use an Electric Fuse in Rust
Every fuse puzzle follows the same pattern. The only thing that changes between monuments is where the boxes are.
- Find the fuse box. It is a grey metal box on a wall, usually inside a small building or shack near the first security door. There is often a repair bench close by.
- Insert the fuse. Open the box (hold E) and drag an Electric Fuse into the slot.
- Flip the switch. A switch box sits next to or near the fuse box. Turn it on and its light goes green. At some monuments the switch is a short walk away, behind a fence or up a ladder.
- Swipe your card. Go to the security door, check that the reader is lit, and swipe the matching green, blue or red keycard.
Move fast after step 3. The fuse only carries power for a short time. Facepunch’s original puzzle notes put it at around three minutes, and when it blows the fuse disappears from the box. Swipe while the reader is powered. A swipe on a dead reader still costs a use on your card, and keycards only last 4 swipes (green and blue) or 2 (red).
Once the door opens it stays open until the puzzle resets, so you do not need a second fuse just to get back out. When the puzzle resets later, the loot room refills and the whole thing needs a new fuse.
Which Monuments Need an Electric Fuse?
This is the full list for the current game, matching our Rust monument puzzles guide:
| Monument | Cards | Fuses | Reward |
|---|---|---|---|
| Sewer Branch | Green | 1 | Blue card room |
| Satellite Dish | Green | 1 | Blue card room |
| Harbor (large and small) | Green | 1 | Blue card room |
| The Dome | Green | 1 | Blue card room |
| Ferry Terminal | Green | 1 | Blue card room |
| Radtown | Green | 1 | Blue card room |
| Water Treatment Plant | Blue | 1 | Red card room |
| Train Yard | Blue | 1 | Red card room |
| Power Plant | Green + Blue | 1 | Red card room |
| Airfield | Green + Blue | 2 | Red card room |
| Military Tunnels | Green + Blue + Red | 1 | Elite loot |
| Launch Site | Green + Red | 2 | Elite loot |
| Underwater Labs | Varies | Some doors | Card rooms |
| Arctic Research Base | Blue | 0 | Red card |
| Missile Silo | Red | 0 | Elite loot |
| Small Oil Rig and Large Oil Rig | Green + Blue + Red | 0 | Locked crate |
The two that trip people up are the Airfield and the Launch Site. Both need two fuses because the puzzle has two separate fuse boxes. Bring two or you will be walking back to a crate halfway through. On the other side, the Missile Silo, the Arctic Research Base and both oil rigs need no fuse at all, so do not waste one there.
Where to Find Electric Fuses
The Electric Fuse is loot only. No recipe, no research and no vendor, so every fuse you use comes out of a container or a body. These are the drop chances from the Facepunch wiki loot tables:
| Source | Amount | Chance |
|---|---|---|
| Tech Parts crate | 1 to 2 | 26.5% |
| Brown crate (normal crate) | 1 | 14.3% |
| Wagon brown crate (trains) | 1 | 14.3% |
| Underwater Lab brown crate | 1 | 14.3% |
| Underwater advanced crate | 1 | 14.3% |
| Tunnel Dweller / Underwater Lab Dweller | 1 to 2 | 7.4% |
| Underwater basic crate | 1 | 4.8% |
| Most scientists (Oil Rig, Cargo, Bradley, patrols, Excavator) | 1 | 4.7% |
| Blue and yellow barrels | 1 | 1.4% |
| Scarecrows and Christmas dungeons (seasonal) | 1 to 3 | 8.8% |
Tech Parts crates are the small grey electrical crates full of components. They spawn in monuments and along the roads, and roughly one in four has a fuse. Brown crates are everywhere, so most players just open every crate on the way to a puzzle and end up with a fuse or two. Fuses are not in the military crate table, so do not count on green crates.
The simplest fuse route is to loot the Tech Parts and brown crates at the monument you want to run. Sewer Branch, the Train Yard and the Water Treatment Plant all have plenty of both.
Electric Fuse Recycle Value
Spare fuses recycle into scrap and nothing else. How much you get depends on the recycler:
| Recycler | Efficiency | Scrap per fuse | Full stack of 10 |
|---|---|---|---|
| Safe zone (Outpost, Bandit Camp) | 40% | 16 | 160 |
| Monument, Power Plant offline | 50% | 20 | 200 |
| Monument, Power Plant powered | 60% | 24 | 240 |
| Red recycler (Power Plant full power) | 75% | 30 | 300 |
24 scrap is a solid return for one slot. Still, keep at least two fuses before you recycle the rest. A fuse is worth far more as a ticket into a blue or red card room than as scrap.
Electric Fuse vs Heavy Fuse
Since the Power Trip update in August 2026 Rust has two fuses, and mixing them up wastes a trip.
| Electric Fuse | Heavy Fuse | |
|---|---|---|
| Shortname | fuse | fuse.highgrade |
| Added | Monument puzzles, June 2018 | Power Trip, August 2026 |
| Goes in | Monument puzzle fuse boxes | Power Plant grid panels |
| Does | Powers a keycard door | Powers recyclers, poles, Dome pumps and events |
| Lasts | A short window | About 2 hours 40 minutes |
| Stack size | 10 | 3 |
| Rarity | Rare | Very rare |
| Recycles into | 24 scrap (16 safe zone) | 24 scrap (16 safe zone) |
| Craftable | No | No |
A Heavy Fuse will not fit a puzzle fuse box and an Electric Fuse will not power the grid. If you plan to light up the Power Plant and run card puzzles on the same trip, carry both. Our Heavy Fuse guide covers the grid phases and how many Heavy Fuses each one needs.
How Many Fuses for a Full Keycard Run?
The classic progression goes green card, blue card, red card, elite loot. Each step costs a fuse:
- Green puzzle, 1 fuse. Sewer Branch, Satellite Dish, Harbor, Dome, Ferry Terminal or Radtown. You come out with a blue card.
- Blue puzzle, 1 fuse. The Water Treatment Plant or Train Yard are the cheapest, needing only the blue card. The Power Plant also wants a green card and the Airfield wants a green card and 2 fuses.
- Red puzzle, 1 or 2 fuses. Military Tunnels takes 1 fuse but all three cards. The Launch Site takes 2 fuses plus a green and red card. The Missile Silo takes the red card and no fuse at all.
So a full run takes 3 fuses on the cheapest route and 4 to 5 if you go through the Airfield or Launch Site. Carry one spare in case someone steals a fuse or you are too slow on the timer.
Electric Fuse Tips
- Always carry a spare. Fuses stack to 10 and take one slot. Two in your pocket means a stolen fuse or a slow swipe is not a wasted run.
- Check the light before you swipe. A swipe on an unpowered reader still burns a card use. Look for the lit reader first.
- Guard the box. In a busy monument, one player watches the fuse box while the others go for the door.
- Loot the Tech Parts crates on site. Most fuse monuments have a few, and one in four drops a fuse.
- Bring protection. Many fuse puzzles sit in radiation, so pack a hazmat suit and meds. See the Rust monuments guide for the radiation level of each one.
- Recycle the extras at a monument. 24 scrap at a powered recycler beats 16 at the Outpost.
Electric Fuse Rust FAQ
What does the electric fuse do in Rust?
It powers monument keycard puzzles. You put it in a fuse box, flip the switch next to it, and the card reader on the security door gets power for a short time so your keycard works. Without a fuse the reader stays dead.
Can you craft an electric fuse in Rust?
No. The Electric Fuse has no blueprint, cannot be researched and is not on the tech tree. No vendor sells it either. Every fuse comes from loot: Tech Parts crates, brown crates, underwater crates, barrels and scientists.
Where is the best place to find a fuse in Rust?
Tech Parts crates, which drop 1 to 2 fuses 26.5% of the time. Brown crates, train wagon crates and underwater crates are next at 14.3%. Tunnel and Underwater Lab Dwellers drop one 7.4% of the time and most scientists 4.7%.
How long does a fuse last in Rust?
Only a short time once the power is flowing. Facepunch’s original puzzle notes said about three minutes, and then the fuse blows and disappears from the box. Swipe your card as soon as the reader lights up. On the ground an unused fuse despawns after 40 minutes.
Which monuments need 2 fuses in Rust?
The Airfield and the Launch Site. Both puzzles have two fuse boxes. Every other fuse puzzle needs one.
Which monuments do not need a fuse in Rust?
The Missile Silo, the Arctic Research Base and both the Small and Large Oil Rig. The Silo and Arctic Base only need a keycard, and the oil rigs use a locked crate you hack instead of a fuse puzzle.
How much scrap is an electric fuse worth in Rust?
24 scrap at a powered monument recycler, 16 at a safe zone recycler, 20 at a monument recycler while the Power Plant is offline and 30 at the red Power Plant recycler.
What is the difference between the Electric Fuse and the Heavy Fuse?
The Electric Fuse opens monument keycard puzzles and stacks to 10. The Heavy Fuse came with the Power Trip update in August 2026, stacks to 3 and only goes into the Power Plant grid panels, where it burns for about 2 hours 40 minutes. They do not work in each other’s boxes.
What is the electric fuse stack size in Rust?
Electric Fuses stack to 10.
Can someone steal your fuse from the fuse box?
Yes. Any player can open the fuse box and take the fuse out, which cuts the power to the door right away. In busy monuments keep a teammate at the box until the door is open.
Sources
- Facepunch Rust Wiki: Electric Fuse (item ID, stack, despawn, loot table, recycle output)
- Rust game item files (rarity, stack size, recycle value for both fuses)
- Rustafied: Monument puzzles are here, June 2018 (fuse boxes, in-game screenshots)
- beancan.gg: Keycards and puzzles (swipe limits, unpowered swipes)