Inline fuses on branch circuits

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Cletis

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Is there anything in NEC that prohibits us from installing inline fuses downstream from first ocpd in accessable jboxes to make multiple lower fused branches ?

Example

Run 1 #10NM home run off a 30 amp single pole breaker 200ft to first jbox, then use 20 amp inline fuse for a 12-2 to some receptacles, then to another jbox to run a few lights off another inline fuse at 15 amp on some 14-2. I'm not saying I would do this but just curious about multiple fuses on an individual branch circuit run similar to parking lot lighting
 
Cletis said:
Is there anything in NEC that prohibits us from installing inline fuses downstream from first ocpd in accessable jboxes to make multiple lower fused branches ?

Example

Run 1 #10NM home run off a 30 amp single pole breaker 200ft to first jbox, then use 20 amp inline fuse for a 12-2 to some receptacles, then to another jbox to run a few lights off another inline fuse at 15 amp on some 14-2. I'm not saying I would do this but just curious about multiple fuses on an individual branch circuit run similar to parking lot lighting
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as long as they are accessible I see nothing wrong. it might make for a bit of a troubleshooting nightmare, but that is not a code issue.
 
Cletis said:
Is there anything in NEC that prohibits us from installing inline fuses downstream from first ocpd in accessable jboxes to make multiple lower fused branches ?

Example

Run 1 #10NM home run off a 30 amp single pole breaker 200ft to first jbox, then use 20 amp inline fuse for a 12-2 to some receptacles, then to another jbox to run a few lights off another inline fuse at 15 amp on some 14-2. I'm not saying I would do this but just curious about multiple fuses on an individual branch circuit run similar to parking lot lighting
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Why would multiple fuses be an issue. No different then a circuit coming from a panel that has been sub feed a few times. I have used inline fuses before-- I don't see an issue with it. Really no different then the picture below. You feed the dryer with a 10/3nm and then you plug the washer into the outlet on the back where the fuses are sized accordingly.

ry%3D480
 
Most inline fuse holders are listed for use only as supplementary protection. You would need a fuse and fuse holder listed for use as branch circuit protection if you wanted to do this.
 
don_resqcapt19 said:
Most inline fuse holders are listed for use only as supplementary protection. You would need a fuse and fuse holder listed for use as branch circuit protection if you wanted to do this.
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Basically, a bussman one like this one

http://www.cesco.com/b2c/product/10974?gdftrk=gdfV25445_a_7c1847_a_7c7081_a_7c10974&gclid=CMT12N6zyMECFUMV7Aod1jQAwQ

don't see it's rated for branch circuit protection but

Another one has this info

Double-Pole Class CC 13?32"" x 1 1?2"" Midget Fuses: Double- pole fuse holder has water-resistant, polarized design, and accepts Class CC branch circuit fuses (Edison fuse types EDCC, HCTR or HCLR, 600V or less) Particularly applicable in street lighting circuits with optional breakaway receptacle


 
Cletis said:
Basically, a bussman one like this one

http://www.cesco.com/b2c/product/10974?gdftrk=gdfV25445_a_7c1847_a_7c7081_a_7c10974&gclid=CMT12N6zyMECFUMV7Aod1jQAwQ

don't see it's rated for branch circuit protection but

Another one has this info

Double-Pole Class CC 13?32"" x 1 1?2"" Midget Fuses: Double- pole fuse holder has water-resistant, polarized design, and accepts Class CC branch circuit fuses (Edison fuse types EDCC, HCTR or HCLR, 600V or less) Particularly applicable in street lighting circuits with optional breakaway receptacle
Click to expand...

It is my opinion that both the fuse and the fuse holder have to be listed as suitable for use as branch circuit protection, not just the fuse itself.
 
don_resqcapt19 said:
It is my opinion that both the fuse and the fuse holder have to be listed as suitable for use as branch circuit protection, not just the fuse itself.
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That is correct, been caught and burned by that mistake. BOTH must be listed for BCP. It gets confusing because the fuses are often the same physical sizes (13/32 x 1-1/2) and fit into the same holders, but not all of the holders are listed for BCP. As far as I know, none of the in-line or panel mount holders for Class CC fuses are LISTED for BCP, but many are UL Recognized (UR), so a panel builder OEM can use them as part of a listed assembly, but not an electrician in the field. But several of the IEC style "flip out" type that mount to DIN rail are UL listed for BCP, you just have to be carefully selective about reading the fine print.
 
Cletis said:
Is there anything in NEC that prohibits us from installing inline fuses downstream from first ocpd in accessable jboxes to make multiple lower fused branches ?

Example

Run 1 #10NM home run off a 30 amp single pole breaker 200ft to first jbox, then use 20 amp inline fuse for a 12-2 to some receptacles, then to another jbox to run a few lights off another inline fuse at 15 amp on some 14-2. I'm not saying I would do this but just curious about multiple fuses on an individual branch circuit run similar to parking lot lighting
Click to expand...
As long as branch circuit protection is provided first then you may consider additional protection as supplimentery protection as I understand it. Look up reference to supplimentery protection in the NEC.
 
templdl said:
As long as branch circuit protection is provided first then you may consider additional protection as supplimentery protection as I understand it. Look up reference to supplimentery protection in the NEC.
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In the example in this thread, the #10s would be a feeder and the #12s the branch circuit. The #10s have 30 amp protection, so the 20 amp fuses are the branch circuit protection for the #12s.
 
don_resqcapt19 said:
In the example in this thread, the #10s would be a feeder and the #12s the branch circuit. The #10s have 30 amp protection, so the 20 amp fuses are the branch circuit protection for the #12s.
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Interesting, never thought of that as a feeder and branch circuit.

Here is an article from EC&M i'm looking at now

http://ecmweb.com/code-basics/article-240-overcurrent-protection

Here are some quotes from that article

A ?supplementary OCPD? provides limited overcurrent protection for specific applications and utilization equipment (Fig. 2). It's usually an internal fuse. Supplementary OCPDs are often used in luminaires, appliances, and equipment for internal circuits and components.
You cannot use a supplementary OCPD as the required branch-circuit OCPD [240.10]. A supplementary OCPD doesn't have to be readily accessible [240.24(A)(2)].

INteresting since it's now a feeder ?? :huh:
 

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I have to disagree with Don on a technicality. The 10/3 is a branch circuit. The fuses in the unit are supplementary in my mind. The branch circuit feeds both the washer and dryer. No different than a water heater with overcurrent protective device in the unit or a electric furnace.
 
Feeder Branch Distinction

The main difference is that a feeder runs between an overcurrent protection device (OCPD) at the supply and a downstream OCPD (typically supplying a branch circuit), while a branch circuit runs between an OCPD and an outlet (or final load). In other words, a feeder supplies power to a branch-circuit OCPD ? which, in turn, powers a branch circuit. However, you size that branch-circuit OCPD based on branch-circuit load calculations (and outlet requirements), not on feeder calculations.

From EC&M article

http://ecmweb.com/code-basics/article-215-feeders
 
Dennis Alwon said:
I have to disagree with Don on a technicality. The 10/3 is a branch circuit. The fuses in the unit are supplementary in my mind. The branch circuit feeds both the washer and dryer. No different than a water heater with overcurrent protective device in the unit or a electric furnace.
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The original post said that the 30 amp circuit fed a 20 amp fuse and the conductors on the load side of the 20 amp fuse fed some receptacles, the 30 amp circuit continued to a 15 amp fuse and conductors on the load side of the 15 amp fuse fed light fixtures. That is a feeder and a branch circuits.
 
I'll have to agree with Don on this one but i'm 50% sure its a feeder/feeder. I had to read this 5x before it sunk in

The main difference is that a feeder runs between an overcurrent protection device (OCPD) at the supply and a downstream OCPD (typically supplying a branch circuit)

and I think that's the case in this example on thread 1


In reality I just run a Al SER to a small sub panel then branch out from there but we worked on a bunch of parking lot lights the other day which gave me the idea of doing it this way to compensate for VD
 
Is it still a feeder if the downstream fuses are only supplemental and not qualified as branch OCPD?
If you do not have branch OCPD, you only have a branch with non-compliant taps.
 
don_resqcapt19 said:
The original post said that the 30 amp circuit fed a 20 amp fuse and the conductors on the load side of the 20 amp fuse fed some receptacles, the 30 amp circuit continued to a 15 amp fuse and conductors on the load side of the 15 amp fuse fed light fixtures. That is a feeder and a branch circuits.
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I thought you were talking about the w/d.
 
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