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What WireEngine checks and what it doesn't

WireEngine is design help for the DC electrical system of a boat, referenced to ABYC E-11. It tells you what it checked, what it could not check, and what it does not cover. It never calls a design finished, and it never signs one off.

What it checks

The checks run on every change, against whatever you have entered so far, and each finding names its ABYC section:

• Wire size against current. Each run's gauge is checked against the most current the wire can carry for its insulation rating (the conductor table).
• Wire size against voltage drop. Each run is checked against a 3 % drop for critical circuits and 10 % for the rest. The gauge must satisfy both the current limit and the drop limit, and whichever needs the thicker wire wins.
• Fuses and breakers. A rating must not be higher than the wire it protects can carry. The fuse must sit close to the power source (within 7 inches, or up to 72 inches for a fully sheathed battery-terminal wire). A positive run with no protection is flagged.
• Bilge pumps. A bilge pump must keep working with the main battery switch off. One fed through the main switch is flagged.
• Negative returns. All DC negatives must come back to one common negative bus.
• Colour coding, labelling, disconnect reach, and AC shore-power basics where the design models them.

How voltage drop is checked

The cited check looks at each run on its own. A circuit is often several runs in a row (battery → switch → bus → load), and the total drop along that path can be larger than any one run's. WireEngine also works out the summed drop along the feed path, but no cited limit for that total is held here, so it is shown as an advisory. It is never a pass or a fail.

What it can't check yet

If a check is missing something it needs, such as a current, a length, an insulation rating or a fuse distance, it does not guess. It lists itself as not checked and names what it needs. A check that did not run has not passed. When the rule it could not run is a shall-level requirement, it is counted on its own as a shall check not run (pending), never with the advisories. Until every check has run and nothing is open, every document says the design is NOT clear for sign-off.

What it doesn't cover

• RVs and vans. You can design an RV or van electrical system, but the rules checked are the marine ones (ABYC E-11). No RV-specific code is checked.
• Anything outside the electrical system. No fuel, plumbing, gas, steering or structural checks.
• The physical wire route. WireEngine does not plan where a wire goes through the boat, how it is supported, or what it passes near. Your installer does that at the boat.
• The boat as built. WireEngine checks the design you entered. It cannot see the boat. A wrong length or a load you did not enter means a wrong answer.
• AC wiring, shore power, grounding and bonding beyond the basics. These are left open for a qualified professional on purpose. The handoff brief lists them.

Where the numbers come from

Every number in a design is one of three things:

• cited, from a manufacturer's document or an ABYC rule, with its source shown;
• worked out by the checks from your other values;
• entered by you, shown as UNVERIFIED until you confirm it.

The design assistant (the chat) can explain things and propose changes. It never sets a safety value such as a wire gauge, a fuse rating or a charge setting. Those come only from the checks, a cited source or you. Each one carries a tier chip that shows which.

What the result means

Even a design with no open items is design help, not a certificate. Have a qualified marine electrician or surveyor look at the boat before you rely on it.