Motor & A/C Equipment Disconnect Location Calculator
Check whether a disconnecting means is in a legal spot under the National Electrical Code (NEC). Pick the equipment and the tool applies NEC 2020 440.14 for air-conditioning and refrigeration equipment and 430.102(B) for motors, keyed on the Article 100 within-sight rule: visible and within 50 ft, readily accessible, and the lockable-open exceptions.
How to use this calculator
- Select the equipment the disconnect serves: air-conditioning/refrigeration equipment (440.14) or a motor (430.102(B)).
- Enter the distance from the equipment to the disconnect and whether it is visible from the equipment.
- For a motor, set whether the disconnect is also visible from the driven machinery. For A/C, set whether it is readily accessible.
- Check the boxes that apply: mounted on an access panel, a cord-and-plug (440.13) disconnect, or the lockable-open industrial exception.
- Read the verdict: compliant, permitted by the exception, incomplete, or a location that does not comply, with the exact issue to fix.
NEC reference
This calculator implements NEC 2020 440.14 (location of the disconnecting means for air-conditioning and refrigeration equipment) and 430.102(B) (location of the disconnecting means for a motor), both keyed on the Article 100 definition of within sight: visible and not more than 15 m (50 ft) distant. 440.14 also requires the disconnect to be readily accessible, permits it on or within the equipment, and prohibits it on a panel that gives access to the equipment; 430.102(B) requires the motor disconnect in sight from both the motor and the driven machinery. The lockable exceptions reference 110.25.
Results are for reference only. Verify against the applicable adopted edition of the NEC and consult a licensed electrician for code compliance.
What "within sight" means
Both 440.14 and 430.102(B) say the disconnecting means has to be "within sight" (or "in sight from") the equipment. That phrase is defined in Article 100, not in the 440 or 430 sections themselves: equipment is within sight from other equipment when it is visible and not more than 15 m (50 ft) distant. Both halves have to be true. A disconnect 60 ft away fails even if you can see it, and a disconnect 10 ft away fails if a wall or a closed door breaks the line of sight. Seeing it through a window does not count.
440.14 vs 430.102(B): what differs
| Rule | A/C & refrigeration (440.14) | Motor (430.102(B)) |
|---|---|---|
| Within sight | Within sight from the equipment | In sight from the motor and the driven machinery |
| Readily accessible | Required (cord-and-plug per 440.13 relaxes it to accessible) | Not stated here (see 430.107 for the group) |
| On the equipment | Permitted on or within it, but not on an access panel | Not addressed by 430.102(B) |
| Lockable exception | Industrial process, lockable per 110.25, qualified persons | Impracticable/added hazard or industrial, lockable per 110.25 |
The lockable-open exception
Both sections let the in-sight disconnect be omitted in narrow cases, and both lean on 110.25: the controller disconnecting means has to be capable of being locked in the open position, with the lock staying in place whether or not the lock is installed. For a motor, 430.102(B) adds that locating the disconnect must be impracticable or introduce added hazards (motors over 100 hp, submersible motors, adjustable-speed-drive motors, hazardous locations), or that the installation is industrial with written safety procedures served only by qualified persons. 440.14 limits its version to air-conditioning or refrigeration equipment that is essential to an industrial process under the same written-procedure, qualified-persons conditions. These are not general-purpose outs; the tool surfaces the conditions rather than assuming them.
Worked example: a rooftop condenser
A rooftop condenser with a fused disconnect bolted to the unit frame, in plain view and reachable from the roof walkway, complies with 440.14: it is within sight, within 50 ft (it is on the unit), and readily accessible. Move that same disconnect inside a mechanical room 70 ft away and it fails twice, on the 50 ft limit and on line of sight. Mount it on the removable service panel of the unit and it fails the access-panel rule, because pulling the panel to service the condenser would remove the disconnect with it. A cord-and-plug mini-split handled under 440.13 only has to be accessible, not readily accessible.
Common mistakes
- Counting line of sight through a window. Within sight means an unobstructed view; glass and closed doors do not qualify.
- Forgetting the driven machinery. A motor disconnect has to be in sight from the machine it drives, not just the motor, so a remote pump or conveyor can force a second disconnect or a relocation.
- Mounting on the access panel. 440.14 permits a disconnect on the equipment, but not on a panel designed to allow access to it.
- Treating the lockable exception as routine. It applies only under its specific industrial or impracticable conditions with a 110.25-lockable controller disconnect.
- Confusing location with rating. Being in the right spot does not size the disconnect; its ampere and horsepower rating follow 430.110 / 440.12.
Frequently asked questions
How far can an A/C disconnect be from the unit?
NEC 2020 440.14 requires the disconnecting means for air-conditioning and refrigeration equipment to be within sight from and readily accessible from the equipment. Article 100 defines within sight as visible and not more than 15 m (50 ft) distant, so the disconnect has to be visible from the unit and within 50 feet of it. A disconnect 60 feet away, or one you can see only through a window or around a wall, is not within sight.
Can the disconnect be mounted on the air-conditioning unit itself?
Yes. 440.14 permits the disconnecting means to be installed on or within the air-conditioning or refrigeration equipment. The one restriction is that it cannot be located on a panel that is designed to allow access to the equipment, because removing that panel to service the unit would take the disconnect with it.
Does a motor disconnect have to be in sight of the motor?
Under NEC 2020 430.102(B), the disconnecting means for a motor must be in sight from the motor location and the driven-machinery location, which means visible and within 50 feet of each. It can be a separate disconnect or the controller disconnecting means serving as the motor disconnect, as long as it is in sight from both.
When is a motor disconnect not required within sight?
The 430.102(B) exception allows the separate in-sight motor disconnect to be omitted where the controller disconnecting means (430.102(A)) is capable of being locked open per 110.25 and either locating the motor disconnect is impracticable or introduces added hazards (for example motors over 100 hp, submersible motors, or motors on adjustable-speed drives), or the installation is industrial with written safety procedures served only by qualified persons. 440.14 has a parallel lockable exception for air-conditioning equipment essential to an industrial process.
What does readily accessible mean for a disconnect?
Readily accessible (Article 100) means it can be reached quickly for operation without having to use a portable ladder, climb over or remove obstacles, or move other equipment out of the way. 440.14 requires the air-conditioning disconnect to be readily accessible. The exception is a cord-and-plug connection under 440.13, where the attachment plug and receptacle serving as the disconnect must be accessible but are not required to be readily accessible.
Does this calculator use the 2020 or 2023 NEC?
It uses the NEC 2020 text of 440.14 and 430.102(B) and the Article 100 within-sight definition. The 50 ft within-sight distance and the readily-accessible requirement are long-standing and unchanged across recent editions; the 2020 wording added the explicit 110.25 lockable reference. Always verify against the edition your jurisdiction has adopted.
Related calculators
- Motor & HVAC Disconnect Sizing Calculator: the ampere rating of the same disconnect per NEC 430.110 and 440.12.
- MCA & MOCP Calculator: minimum circuit ampacity and maximum overcurrent protection for HVAC equipment per Article 440.
- Equipment Service Receptacle Calculator: the 210.63 servicing receptacle within 25 ft of the same HVAC equipment.
- Motor Breaker Sizing Calculator: branch-circuit short-circuit and ground-fault protection for a motor per NEC 430.52.
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