Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
roconnor wrote:
Okay ... so the wrong Type-S adapter was installed there. If ya look at the Bussman cut under SA-20 it will only take a 20A fuse. A 30A fuse will not fit in the 20A adapter (as it should be ...  ).
The adapter should be clearly marked ... like the pic I posted above of a Bussman SA-15 plug fuse adapter.
I am not quite sure how they do that. The 20 and the 30 have exactly the same threads. I am not sure what the difference between a s-20 and s-30 adapter is.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
roconnor wrote:
P.S. ... I actually think that breaker panels are unsafe as compared to fused panels ... put that one in your pipe and smoke on it for a bit ... 
Just because a technology is old, doesnt mean it is inferior.
... I see a large white rabbit ... ohhhhh, and a ...
Guess I smoke too much of that?
I disagree with your first statement, and age has nothing to do with it. A fine wine gets better with age, but a bad wine just gets worse.
I think that breaker panels are safer than fuse panels ... when you consider the overall aspect of "safety". It is much easier to tamper with a fuse panel than with a breaker panel, and any tampered with panel becomes less safe, and any panel which has its overcurrent protection tampered with become UNSAFE.
I don't know about you, but I have NEVER seen a breaker wrapped in aluminum foil or have a wire going from breaker connection, around the breaker, to the circuit conductor (which would be like the penny).
Originally Posted By: jpeck This post was automatically imported from our archived forum.
The Safe-T-Fuse length is different.
The longer ones hit bottom and don't touch the top if in the wrong adapter. The shorter ones hit the top and don't touch bottom if in the wrong adapter.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Greg Fretwell wrote:
I am not quite sure how they do that. The 20 and the 30 have exactly the same threads. I am not sure what the difference between a s-20 and s-30 adapter is.
Some manufacturers have courser threads for larger fuses, and as Jerry suggested other manufacturers may have different lengths. NEC 240.53 just requires that the adapters be made so they can not be overfused.
jpeck wrote:
I think that breaker panels are safer than fuse panels ... when you consider the overall aspect of "safety". It is much easier to tamper with a fuse panel than with a breaker panel, and any tampered with panel becomes less safe
I would agree that breaker panels are safer than standard fused panels without the safety adapters/fuses installed. But NFPA changed that.
I think a fused panel with the Type-S safety adapters/fuses installed is much safer. Shunting with a penny will not work because the contact points are the center button and the top rim of the adapter, and the threads are finer with a tighter fit which doesn't allow a type-s fuse to just be wrapped in foil and screwed in. Once an adapter is installed, it is actually more difficult to remove in order to install an oversized fuse, than it is to swap out for an oversized breaker.
Someone who is hell bent on tampering with a circuit will probably find a way, but I think that actually becomes more difficult with the safety fuses/adapters. Considering that breakers have a higher failure rate than fuses, I will stick with a fused panel being safer as long as the Type-S fuses/adapters are installed.
Just my opinion and 2-nickels ... 
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
jpeck wrote:
The Safe-T-Fuse length is different.
The longer ones hit bottom and don't touch the top if in the wrong adapter. The shorter ones hit the top and don't touch bottom if in the wrong adapter.
That makes sense, but how does a 20 and a 30 still work in a S-30 adapter? If one is longer the other should not work. I still have the bag of 30s, I will get a 20 and we can compare them.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
Greg Fretwell wrote:
jpeck wrote:
The Safe-T-Fuse length is different.
The longer ones hit bottom and don't touch the top if in the wrong adapter. The shorter ones hit the top and don't touch bottom if in the wrong adapter.
That makes sense, but how does a 20 and a 30 still work in a S-30 adapter? If one is longer the other should not work. I still have the bag of 30s, I will get a 20 and we can compare them.
Here is the answer. They are exactly the same length and thread. See the reduced size of the tip on the 20? It goes into a recess in the S-20 adapter. I am convinced, sorry for the FUD