Old Forgotten Ways

@Mad Dog_2 I used to tell my CO to just tell me what he wanted done and let me figure out how to do it. He learned it was best if he did not know how it got done.

'These days you hear about the E4 mafia in the service, back in the 60's it was the SP5 mob. E5 was just high enough to get you out of the swamp (guard duty and KP) but not high enough to burden you with any real responsibility - that freed us up to work the deals that kept the organization going. It worked very well till some Lt asked "how did you do this", mu answer was you don't want to know.

I have seen electricians trace wires in interesting ways. One guy had a light switch in a regular switch box with a male plug. One wire went to the hot blade and the other to the ground prong. He would flip the switch to off, plug the pig tail into an outlet, then flip the light switch on. Then go to the service panel to see which breaker tripped.

A safer method, which I have seen many times, but never took the time to figure it out, two old fashion telephone handsets and a 9v battery. If you were on the same wire, you can speak to each other.

a d cell would probably be sufficient, you just put the transmitter in series with the battery and the carbon mic element makes a varying current from speech that the speaker in the receiver can turn in to sound.

there were some that used a dynamic mic that could produce enough current to power the receiver just from the sound.

most branch circuit wiring is capable of safely carrying more current than what the code requires it be fused at anyhow. the ampacity is by decree in a rule, not by heat generated and insulation temp rating

electrical fires happen far more from bad terminations than from overloading the conductors.

are we just talking type s fuses and those adapters that make it a huge pain if you need to fix something with the fuse panel?

That was another name for them.

the early site made fuse panels with individual fuseholders were usually pretty sketchy but most of the mid century factory made fuse panels are pretty solid as long as they didn't get wet. i have seen a lot of sketchy 70's era fuse and breaker panels, even ones that aren't the infamous ones. should there be more than just a piece of glorified cardboard keeping the bus from touching the enclosure?…

Ah so? A modern fuse is hardly inferior technology. I'll grant that there are two add-ons which fuses can't do — ground fault protection for milliamp faults and arc fault protection (but that latter, in my humble opinion is not a mature technology at this point). The type S fuses — the only ones I'd use in fuse panels with Edison type bases — are "slow blow" fuses, meaning they have a time to blow vs. current curve which allows for momentary overloads, such as motor starting or even current inrush on some lighting applications. However, in cartridge fuses the range of time delay on overcurrent is extraordinarily large, ranging from fuses — like the type S, but with more variety in time delay — to fuses which will blow reliably with microseconds of a current ramp exceeding their rating, which — obviously — should only be used to protect very sensitive electronics.

One of the overlooked aspects of fuses — particularly cartridge, but also type S — is that it is almost impossible for them to fail fused closed, unlike almost all enclosed circuit breakers which can and do fail closed if presented with a high overvoltage at the same time as a high current.

It is no coincidence that virtually all grid wiring and devices are protected by fuses. Circuit breakers are used in places like substations, but more as high voltage switches with reclose capability, and there is almost always a fuse in play as well.

Now I quite agree about looking at older fuse panels with some suspicion! But that also applies to some older circuit breaker panels. Now if you encounter a fuse panel which has NOT been converted from Edison base to type S, either replace it with breakers — or just add type S converters (check the wire gauge and insulation type for proper size!)

And if you encounter a panel — of any type or age — which has gotten wet, just replace it. It's done.

And don't assume that someone along the line has always used the correct rating circuit breaker. It is just as easy to swap in a higher rating circuit breaker for a circuit which is overloaded as it is to swap in a higher rated Edison base fuse. There is ample YouTube guidance for the ambitious homeowner to do just that…

the problem with figuring overcurrent protection after the fact is that you have to examine the whole circuit both for gauge of wiring and for utilization equipment that may need a lower rating of overcurrent protection than the wiring or that may fall under one of the next standard size up exceptions.

i'm not sure about the AFCIs. The ones I installed 20 years ago needed to bake some more but the ones I bought about a year ago seem to have solved most of the problems of the early ones.

how does a remote trip fuse work? say you want the main to trip if you detect a fault in a surge suppressor, how do you do that with a fuse?