Rooftop HVAC equipment feeders single line diagram
Mechanical panel with breakers and disconnects sized from nameplate data. Use this for rooftop units and other HVAC equipment fed from a mechanical panel, each with its own breaker and a disconnect at the unit.
A free template with typical ratings, conductor callouts and general notes. Open it, change what differs on your job, fill in the title block and export a PDF.
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What the reviewer checks on this drawing
The reviewer checks each breaker against the nameplate maximum overcurrent protection (MOCP), each conductor against the minimum circuit ampacity (MCA), a disconnect within sight of every unit, and the service receptacle near the rooftop equipment.
What the drawing shows
Every device on the sheet, in the order power reaches it.
| Symbol | Label | Rating or detail |
|---|---|---|
| Device | From MDP (MDP) | Existing feeder |
| Circuit breaker | 225A 3P | Main |
| Panel | Mechanical panel MP | 225A · 120/208V 3φ 4W |
| Circuit breaker | 60A 3P | RTU-1 |
| Disconnect switch | Disconnect | 60A · NEMA 3R |
| Load | RTU-1 | MCA 42A · MOCP 60A |
| Circuit breaker | 45A 3P | RTU-2 |
| Disconnect switch | Disconnect | 60A · NEMA 3R |
| Load | RTU-2 | MCA 33A · MOCP 45A |
| Circuit breaker | 30A 2P | CU-1 |
| Disconnect switch | Disconnect | 30A · NEMA 3R |
| Load | CU-1 | MCA 18A · MOCP 30A |
| Circuit breaker | 15A 3P | EF-1 |
| Disconnect switch | Disconnect | 30A |
| Motor | EF-1 | 1 HP exhaust fan |
Notes on the sheet
- Breakers do not exceed the nameplate maximum overcurrent protection (MOCP); conductors sized from minimum circuit ampacity (MCA).
- Disconnect within sight of each unit. Service receptacle within 25 ft of rooftop equipment.
- Replace MCA and MOCP values with the nameplate data of the installed equipment.
Diagram is schematic and not to scale. Field-verify existing equipment ratings. Ratings and conductor sizes shown are typical. Confirm against the adopted code, the equipment listing and a load calculation before installation. Code references are to the 2023 NEC and the 2024 Canadian Electrical Code: see references and editions.
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