How to build an electrical panel schedule that inspectors and service techs can trust
A panel schedule is one of the few documents that lives with the building for decades. The engineer draws it, the electrical contractor builds to it, the inspector checks it, and the service tech who opens the door ten years later depends on it. When it's wrong — circuits moved in the field, loads added without updating the totals, a door card that says "recepts" for half the breakers — everyone downstream pays for it. This guide walks through each part of the free Excel panel schedule above so you can fill it out correctly the first time and keep it accurate through turnover.
Panel information: the header block
Before a single circuit goes in, capture the panel data. The template has a header block for all of it:
- Panel name and location — match the one-line diagram and the room number on the drawings (LP-1, Electrical Room 104).
- Voltage and system — 208Y/120V 3Ø4W for most commercial branch panels, 480Y/277V 3Ø4W for lighting and mechanical panels in larger buildings, 120/240V 1Ø3W for residential and small commercial.
- Main breaker or MLO — a main-breaker panel has its own overcurrent device; a main-lugs-only (MLO) panel is protected by the feeder breaker upstream.
- Bus rating — the ampacity of the panel bus (often one size above the main, e.g., 225 A bus with a 200 A main).
- AIC rating — the interrupting rating of the breakers (10 kAIC, 22 kAIC, 65 kAIC). It must meet or exceed the available fault current at the panel.
- Mounting and enclosure — surface or flush; NEMA 1 indoors, NEMA 3R outdoors.
- Fed from and feeder size — the upstream panel and breaker, plus conductors and conduit.
Two of those cells drive the math: line-to-line voltage (208, 480 or 240) and number of phases (3 or 1). Every amps calculation in the workbook reads them.
The 42-circuit layout and phase rotation
A standard panelboard has odd circuits down the left (1, 3, 5…) and even circuits down the right (2, 4, 6…). Each horizontal pair lands on the same bus phase. On a three-phase panel the phases rotate A, B, C down the panel, so circuits 1-2 are on phase A, 3-4 on B, 5-6 on C, then 7-8 are back on A. On a single-phase 120/240V panel they alternate A, B.
The template's center Phase column calculates the rotation automatically and grays out the VA columns that don't apply to each row, so you enter each load's VA on the correct phase. Multi-pole loads span rows: a 2-pole water heater on circuits 27 and 29 puts half its VA on phase B and half on phase C; a 3-pole rooftop unit puts one-third on each phase.
Load type codes
Each circuit gets a one-letter type so the demand calculation can apply the right factor:
| Code | Load type | Typical examples |
|---|---|---|
| L | Lighting | Interior fixtures, exit signs, site lighting |
| R | Receptacle | General-purpose convenience outlets (180 VA per yoke for calculation) |
| M | Motor | RTUs, exhaust fans, pumps, compressors |
| H | Heat | Unit heaters, baseboard, water heaters, duct heaters |
| K | Kitchen | Commercial cooking and food-service equipment |
| O | Other | IT, copiers, fire alarm, controls, dedicated equipment |
Connected load, phase balance and demand load
Connected load is everything on the panel at 100% — the sum of VA on each phase. The template totals it per phase and in kVA, converts each phase to amps (phase VA ÷ line-to-neutral voltage), and shows the percentage on each phase.
Phase balance matters because the neutral and the heaviest phase conductor carry the imbalance. The template calculates the heaviest phase's deviation from the average; a common target is under about 10%. If you're over, move a few single-pole loads from the heaviest phase to the lightest.
Demand load is what the feeder and main actually need to carry. The template groups connected VA by type and applies an editable demand factor to each (100% by default — the conservative starting point). It also includes three NEC-based adjustments. Section numbers below follow the 2020/2023 NEC; verify against your adopted NEC edition and any local amendments:
- Receptacles (NEC 220.44) — for non-dwelling occupancies, the first 10 kVA of receptacle load at 100% and the remainder at 50%. Flip the Y/N switch to apply it.
- Continuous loads (NEC 215.2(A)(1), 210.20(A)) — loads running three hours or more, which usually includes commercial lighting, are sized at 125%. The template adds 25% of lighting load; set it to 0% if your lighting isn't continuous.
- Largest motor (NEC 430.24, 220.50) — add 25% of the largest motor's load. Enter the total VA of the largest motor.
From the total demand kVA the template calculates demand amps: kVA × 1000 ÷ (V × √3) for three-phase, or kVA × 1000 ÷ V for single-phase. It compares that to the main breaker (or bus rating on an MLO panel), shows the percentage used with an in-cell bar, and reports spare capacity. When you're above about 80%, you have little room left for future tenant or owner additions.
The circuit directory (door card)
NEC 408.4(A) requires every circuit and circuit modification to be legibly identified as to its clear, evident and specific purpose. The Circuit Directory tab pulls every description from the schedule automatically — edit the schedule and the door card updates. Print it portrait, trim it, and mount it inside the panel door. Be specific: "Receptacles — Office 101-102" is useful at 2 a.m.; "Recepts" is not.
Common panel schedule mistakes
- Field changes never make it back to the schedule. A circuit gets moved to balance phases or free up a slot, and the as-built schedule still shows the old position. Update the sheet the same day.
- Multi-pole loads entered on one phase. A 3-pole RTU entered as 7,500 VA on phase A makes the balance look terrible and the per-phase amps wrong. Split it across the rows it occupies.
- Missing type codes. Untyped circuits still count toward connected load (the template catches them on an "untyped" line) but skip the right demand factor.
- Spare vs. space confusion. A spare has a breaker installed; a space doesn't. Owners and future contractors plan around the difference.
- Wrong voltage in the math. Using 120 instead of 208 for a three-phase calculation roughly doubles the amps. Double-check the L-L voltage cell.
Related electrical references
- Wire ampacity chart — size branch circuits and feeders from the NEC 310.16 table
- Equipment grounding conductor chart — EGC size by overcurrent device rating (Table 250.122)
- Voltage drop calculator — check long feeder and branch runs before you upsize wire
- Electrical contractor software — daily reports, T&M, budgets and job files in one app
- Browse all free construction templates
When a spreadsheet isn't enough
A panel schedule in Excel works well for a single panel or a small job. On a project with dozens of panels, multiple foremen, and change orders adding circuits every week, versions multiply and the as-builts drift. Field PM keeps every panel schedule, drawing and turnover document in the project Job Book, alongside daily reports, T&M tickets and budget tracking built for electrical contractors. Start a free 30-day trial — no credit card required.
