Correct configuration of metal fuse element in C2 fuses

[Gary B.]

[Thomas S.]

Re: Correct configuration of metal fuse element in C2 fuses

As I had point out in one of my comments, I've been in the wholesale electronics business since 1971. Every low amperage fuse that was made by Bussman or Littelfuse had a wire filament. 4A would be considered low amperage. Within the lower range you typically had zig-sag wire and in the extreme low range, fine straight wire filaments The higher ranges were always flat filaments. In some cases they had notches (dog-bone) or tapered cutouts. These fuses were never painted or color coded and they were exclusively marked with a stamped end-cap. The designation for the size was 3AG. The Bussmann series was AGC and the Littelfuse was 312

The smallest cross-section area of the conductor determines the current capacity. In a round wire, this is referred to has (circular mils) and a rectangular section follows the same logic. The purpose of the zig-zag or twisting is to provide mechanical support for the filament. The cross section area required to make a 4A fuse using a flat conductor would be so small that it would be impractical to manufacture.

These type of devices are not high tech and the design and assembly processes haven't changed. Material used in the process have changed due to lead content or other banned metals which may have been used to plate the end caps. While there was a host of 3rd and 4th tier company's making fuses, the physics would have changed and they likely all took the same approach.

Having said all of that, I would suggest that the JG description is incorrect if they are implying that the 4A fuse has a flat filament. The challenge would be to show evidence of any GM vehicle from that period with a 4A fuse. We have not established the source for the GM fuses and without that information it is impossible to know for sure.

What does the JG say about fuses from a late C1 era car?

[Gary B.]

Re: Correct configuration of metal fuse element in C2 fuses

Thomas,

What’s your impression of the fuse in the 4-amp slot my post #5? Have you ever seen another fuse that looks like that?

Gary

PS. Thanks for the detail about the 312 series by Littelfuse. I knew there was a Littelfuse 311 series and a 312 series, but I didn’t know if either was correct for the C2 era.

[Gary B.]

Re: Correct configuration of metal fuse element in C2 fuses

[Joseph S.]

Re: Correct configuration of metal fuse element in C2 fuses

Gary, It probably will not change in the next revision of the 63-64 Guide. As long as the fuses are clear glass the owner should get full credit for them. This is another item that may certainly be details for conversation, and for the owner that wants the most technically correct restoration. However, there is no bearing on judging points due to the fuse panel & wiring have a total value of 5 points. 1 or 2 mismatched fuses should not cause a deduction. It's way too minor of a detail considering all the wiring, routing, connectors, fuse block itself, etc.

[Gary B.]

Re: Correct configuration of metal fuse element in C2 fuses

Thanks Joe. Your input is invaluable.

Gary

[Thomas S.]

Re: Correct configuration of metal fuse element in C2 fuses

The 4A fuse in post #5 is weird looking, Honestly, never saw one like that. It looks like there is a wire between two flat conductors which would not be cost effect to make, or it could be a flat filament notched to create a thin 4A fusible section. You can see on one end cap the designation of 3AG which is the industry size reference for a 1/4" x 1-1/4" glass size fuse. The littelfuse 311 would have a ceramic body, 5mm x 20mm long.

Bussman AGC

https://www.eaton.com/content/dam/eaton/products/electronic-components/resources/data-sheet/eaton-agc-fast-acting-glass-tube-fuses-data-sheet.pdf

[Gary B.]

Re: Correct configuration of metal fuse element in C2 fuses

The 4A fuse in post #5 is weird looking, Honestly, never saw one like that. It looks like there is a wire between two flat conductors which would not be cost effect to make, or it could be a flat filament notched to create a thin 4A fusible section. You can see on one end cap the designation of 3AG which is the industry size reference for a 1/4" x 1-1/4" glass size fuse. The littelfuse 311 would have a ceramic body, 5mm x 20mm long.

Bussman AGC

https://www.eaton.com/content/dam/ea...data-sheet.pdf

[Gary B.]

Re: Correct configuration of metal fuse element in C2 fuses



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[Edward B.]

Re: Correct configuration of metal fuse element in C2 fuses

Probably not acceptable:

[Gary B.]

[Jack J.]

Re: Correct configuration of metal fuse element in C2 fuses

[ATTACH=CONFIG]116014[/ATTACH]

. I have 1 (one ) blue colored fuse rated 20 amp and a few tan/brown colored fuses rated 5 amp. Jack J.

[Gary B.]

[Jack J.]

Re: Correct configuration of metal fuse element in C2 fuses

[Gary B.]