I bet most of you here haven't seen a fuse this big

Referenced to 4D Maglite.


I found it while urban exploring. It is blown and worthless, but still cool.
600V AC, 1200A
interrupting capacity, 200,000A
4 lbs 6oz, or about 2 kg

That is just unreal.

I wonder what it was installed in...

TigerhawkT3 said:

That is just unreal.

I wonder what it was installed in...

Click to expand...

It was found among other debris in an electrical room(rather, what used to be) of a building that will be demolished. The transformer was de-energized, but still there, which was about the size of a GMC Yukon. I think the monster was rated at 3φ 7200/4160 to 480/277, 1,000kVA or so.

This thing was probably a fuse holder for the primary side fuse. This weighs 6.5 lbs (3kg). It's rated for maximum voltage of 7,500v and meant for use with a fuse up to 200A. Again, referenced to 4D Maglite.

Not bad.

These used to be common place. Most of the switch boards these days use auto reseting 3 phase breakers with shunt trips and castel interlocks (In Australia anyway). The breakers for large domestic (Unit blocks), Commercial and industrial site's can cost as much as a standard family car some times a luxury model!

I used to be around the mining and smelting industry a lot so these look very familiar; however certainly not a common household item .

I actually have one of those fuses in my basement somewhere.

Came out of a piece of switchgear in a building electrical room much as described here. The blades of the fuse were silver plated. Can't tell if yours was or not.

Fused panels like that are still fairly common around here.

hahahaa - I love it ! A 200,000 amp 'fuse'. It's probably just a solid peice of metal, and when the metal melts, the 'fuse' is blown ( LoL ). Good stuff.

I just wanna know what blew it!

I have a rental property that used to use two 100 amp fuses at the pole. They looked like small versions of yours. One time I had to evict a couple that quit paying rent and were trashing the place. Before they left they also took those two fuses. Probably threw them in the trash to be jerks. Anyway, the replacements were almost $200 apiece. I was pissed! I can't imagine what yours would cost new when that tech was still current.

Yep, seen many of them. Actually we still have quite a few in service. About $325 each for a Shawmut 2,000A one.

The Blades are solid copper with silver plating.

Ah, a Bussman Class L fuse. I work for a company, Boltswitch that makes the switches for those fuses. www.boltswitch.com

That's a 1200 amp fuse. The 200,000 amps is the fault current rating which is the maximum amount of current the fuse can interrupt.

We make switches up to 6000 amps. (4000 amps UL listed) Basically they look like a refrigerator with a handle on the front.

Pretty cool stuff.

:huh: 1,200A 600V time-delay Limitron with 200,000A IR is $325 on Grainger. The fast acting version is around $530 and there are three of them per panel feeder. So a big time phase-to-phase short would claim at least $650 in just fuses. After you include the cost of damage to other parts and labor, a short in an industrial setting would probably create a repair bill similar to a collision repair bill. The disconnect switch lever at the fuses look like a tire iron with a button on the end and is about 16" long. This one lever disconnects all three phases of the 480V main feed.

Busbars that connects to these fuses.


I haven't found the disconnect switch for the 7.2kV side yet.

These fuses were placed upstream of BIG main breakers that fed sub-panels. The larger breaker required such a force to activate it that there is a slip on fitting with a bar for operating the lever.


480V 300A breaker that feeds a sub-panel.

man I love urban exploration..

Kryosphinx said:

I just wanna know what blew it!

Click to expand...

1201 Amps!

Roger

Wow, those are huge! My radars I work with have one 350 Amp fuse in them and I thought that was quite a bit of current. Those monsters fuses in your post are the biggest I've seen.

It is kind of funny, but the circuit that has the 350 Amp fuse in my radar has a smaller fuse (5 Amp) in parallel with it. There is a small "stinger" that pops out when the fuse blows and hits a microswitch, lighting a red light that tells you the fuse has blown. I've seen a couple times where the the 350 Amp fuse has blown, but the smaller fuse is still working! It will let the circuit power up, but when you kick in the high voltage transformer, it faults out. The small fuse will still be good, but it can't handle the current. Very strange. Thanks for the pics.

Handlobraesing said:

Referenced to 4D Maglite.


I found it while urban exploring. It is blown and worthless, but still cool.
600V AC, 1200A
interrupting capacity, 200,000A
4 lbs 6oz, or about 2 kg

Click to expand...

Its absolutely no fun whatsoever moving those things around when there are milkcrates full of them on the job.

Its amazing how much weight can be centralised into such a small space.

Oops, I was wrong on the transformer specs. Upon closer inspections, the correct specs are,

4160V (delta) (with multiple taps) --> 480Y/277V, 2400A
2,000kVA (how bright would a two million watt light be? )

Your average 200A 240/120V home service is 48kVA

Transformer tag

Total weight: 14250 lbs, of that, 5044 lbs is just the case, which weighs as much as a full size pickup.

Fill capacity:

transformer: 354 GALLONS
switch chambers: 23 GALLONS


Panel with fuses in place. These ones are even bigger and fat as a soda can 2000A 600V rated with 200kA IR.

Handlobraesing said:

Oops, I was wrong on the transformer specs. Upon closer inspections, the correct specs are,

4160V (delta) (with multiple taps) --> 480Y/277V, 2400A
2,000kVA (how bright would a two million watt light be? )

Your average 200A 240/120V home service is 48kVA

Transformer tag

Panel with fuses in place. These ones are even bigger and fat as a soda can 2000A 600V rated with 200kA IR.

Click to expand...

We have some of those transformers in service here at work. Built in the 60's but have been upgraded to "dry" type. That buss bar is worth a few bucks in scrap copper. Nice find handling.

That transformer's date coded 1985, far from dry. Almost 380 gallons of oil. If it were diesel fuel, that's a one year supply of fuel for Golf TDI.

Man, don't tell me I need to start collecting fuses too. I already collect everything under the sun. Great pix!