ABYC definition of “conduit”

[Drennan]

Owing to space constraints, I must place a Class-T fuse 25”-30” from my LFP house battery. ABYC code permits up to 40” through “conduit”.

Am I limited to flexible/rigid PVC & metal conduit, or might some other, and more flexible types of cable enclosure be acceptable? If not, I’ll need a much different plan B.

Thank you

[s/v Jedi]

Originally Posted by Drennan

Owing to space constraints, I must place a Class-T fuse 25”-30” from my LFP house battery. ABYC code permits up to 40” through “conduit”.

Am I limited to flexible/rigid PVC & metal conduit, or might some other, and more flexible types of cable enclosure be acceptable? If not, I’ll need a much different plan B.

Thank you

Are you in the US? If so, then Amazon has this: https://www.amazon.com/gp/product/B00008VFAP

Elsewhere it is easy to get in most stores as well as online.

[Fishspearit]

Directly off the battery ABYC allows up to 72 inches in a conduit. The conduit does not have to be rigid, you can use spiral wrap, or split loom. They even permit electrical tape spiral wrapped around the conductor. The goal is to provide some other type of chafe protection besides the manufacturer's insulation if you are not physically able to provide overcurrent protection within 7 inches.

[s/v Jedi]

Originally Posted by Fishspearit

Directly off the battery ABYC allows up to 72 inches in a conduit. The conduit does not have to be rigid, you can use spiral wrap, or split loom. They even permit electrical tape spiral wrapped around the conductor. The goal is to provide some other type of chafe protection besides the manufacturer's insulation if you are not physically able to provide overcurrent protection within 7 inches.

That is good to know

In that case, for the OP, you can consider this, which is my latest favorite type of split loom, because it overlaps at the split and has a smooth exterior: https://www.amazon.com/gp/product/B07FW672R7

[Scubaseas]

Literally "11.4.8 Conduit - an enclosure that is part of a closed wiring system for insulated conductors and/or cables in electrical installations, allowing them to be drawn in and/or replaced."

[Fishspearit]

Originally Posted by Scubaseas

Literally "11.4.8 Conduit - an enclosure that is part of a closed wiring system for insulated conductors and/or cables in electrical installations, allowing them to be drawn in and/or replaced."

Sigh... I didn't correct him on his use of the word conduit and should not have used it myself. ABYC does not require conduit, they require a "sheath or enclosure such as conduit".

Sheath is as I described.

ABYC 11.10.1.1.1 Overcurrent Protection Device Location - Ungrounded conductors shall be provided with overcurrent protection device(s) within a distance of seven inches (178 mm) of the point at which the conductor is connected to the source of power measured along the conductor (see FIGURE 8). EXCEPTIONS: 1. Cranking motor conductors.2. If the conductor is connected directly to the battery terminal and is contained throughout its entire distance in a sheath or enclosure such as a conduit, junction box, control box, or enclosed panel, the overcurrent protection shall be placed as close as practicable to the battery, but not to exceed 72 in (183 cm).

From the USCG Boatbuilders handbook:
I 8ELECTRICAL SYSTEMS – 33 CFR 183 SUBPART I2.4 SHEATH. Sheath means a material used as a continuous protective covering, such as electrical tape, molded rubber, molded plastic, or flexible tubing around one or more insulated conductors.A “sheath” is a flexible continuous covering, as distinguished from a “conduit” or “duct” which are rigid continuous coverings. As the regulation states, a “sheath” may be a continuous wrapping of electrical tape, molded or extruded rubber or plastic, or flexible tubing (sometimes referred to as “spaghetti”).A “sheath” may be used around one or a number of conductors, which may or may not be different gauges. Each of the conductors must be insulated, that is, the sheath is NOT to take the place of a conductor’s insulation.A “sheath” does not have to hold the conductors tightly bonded together. Individual conductors are allowed to move in relation to each other within a sheath. A “sheath” is generally used as a means of...

[Drennan]

My thanks to all the helpful options; you’ve made me good to go.

Sorry about the 40” vs 72” rule error. “40” has been on the brain since last week - when my septic tank contractor backhoe’d our buried power line - which was installed below 40” as required by the building code.

[Scubaseas]

Just support whatever you have every 18" or less.

[Bowdrie]

I have a battery cable where I used a length of Gates automotive "Heater hose" as a flexible "conduit".

[Fishspearit]

Originally Posted by Drennan

My thanks to all the helpful options; you’ve made me good to go.

Sorry about the 40” vs 72” rule error. “40” has been on the brain since last week - when my septic tank contractor backhoe’d our buried power line - which was installed below 40” as required by the building code.

The 40" is valid, that's the requirement (and it's a USCG requirement not just an ABYC recommendation) for the distance that you are allowed to go before overcurrent protection in a 'sheath or enclosure' for any electrical wiring OTHER than one connected directly to the battery. They let you go the extra 32 inches from a battery because they know we like to put them in hard to reach areas.

[wyb2]

Originally Posted by s/v Jedi

That is good to know

In that case, for the OP, you can consider this, which is my latest favorite type of split loom, because it overlaps at the split and has a smooth exterior: https://www.amazon.com/gp/product/B07FW672R7

Big second vote this stuff. Tool-less install, can be easily opened up at any time, tougher than it looks, and as a bonus the mesh design means it can’t trap water.

[team karst]

Originally Posted by wyb2

Big second vote this stuff. Tool-less install, can be easily opened up at any time, tougher than it looks, and as a bonus the mesh design means it can’t trap water.

🤯 Polyethylene is a poor choice for wire and any wireways. Highly flammable unless its got FR additives. PVC can be easily found with UL fire ratings.

[s/v Jedi]

Originally Posted by team karst

�� Polyethylene is a poor choice for wire and any wireways. Highly flammable unless its got FR additives. PVC can be easily found with UL fire ratings.

It is UL listed and has higher temperature ratings than the insulation of marine grade wire that you put in. I guess it has the additives you talk about?

[team karst]

From UL “boat wire “ spec:


Temperature rating is not a good indicator of flame rating. That covers melting, cold cracking, and related.
AFA, wireways, i will make a bit of a risky evaluation and say they should have the same flame and halogen smoke rating as the wires within. True for many non-marine industries.

Generally, avoid styrofoams and polyethylenes. Coax cables usually contain polyethylene as a center insulator, but are surrounded by metal. So that helps, but not good enough for air plenums and the like. Its a minefield of specs.

[wyb2]

Originally Posted by team karst

🤯 Polyethylene is a poor choice for wire and any wireways. Highly flammable unless its got FR additives. PVC can be easily found with UL fire ratings.

Sorry about your head.

Amazon is the wild west of product descriptions. Even without knowing that polyethylene would be a problem here (I hadn’t thought about it), I would have given it a 50/50 chance of getting the material correct. You basically just have to rely on the fact that no one is setting up a separate production run for something like that to sell on Amazon.

It’s not a perfect system , I definitely got copper clad aluminum wire once when it clearly stated solid copper.

Looks like the same stuff from McMaster is listed as “polyester fabric”, and you can get it as ‘standard’, VW-1 flame rated, or NFPA 262 plenum rated. My guess is the Amazon stuff is exactly the same as the ‘standard’ stuff from Mcmaster.

You do bring up a good point. In the future I’ll probably opt for the VW-1 stuff from McMaster, looks like it’s a very small extra cost. The plenum rated stuff is a 5x the price, might take my chances and pass on that.

https://www.mcmaster.com/9196K14

I wonder what the flame rating of my plywood bulkheads is?