Power feeds should support one-to-many connections for residential/home use cases

[sebmuc99]

NetBox version

v4.2.0 (and earlier)

Feature type

Change to existing functionality

Proposed functionality

Allow power feeds to connect to multiple device power ports instead of the current one-to-one limitation. This would enable accurate modeling of residential, small office, and industrial electrical installations where one circuit breaker powers multiple wall outlets or devices.

Use case

The Real-World Scenario

In residential electrical systems, a single circuit breaker (power feed) typically powers multiple wall outlets, and each wall outlet can power multiple devices (either directly or via power strips). For example:

Circuit Breaker: F12-Kitchen-Outlets (16A)

• Powers: KI-OL-01 (Wall Outlet Kitchen 01)
• Powers: KI-OL-02 (Wall Outlet Kitchen 02)
• Powers: KI-OL-03 (Wall Outlet Kitchen 03)
• Powers: KI-OL-04 (Wall Outlet Kitchen 04)

Each wall outlet then powers one or more devices:

• KI-OL-01 → Refrigerator
• KI-OL-02 → Power Strip → Coffee Maker + Toaster
• KI-OL-03 → Dishwasher
• KI-OL-04 → Microwave

The Problem

NetBox currently allows a power feed to connect to only ONE device's power port. This means I can only connect F12-Kitchen-Outlets to KI-OL-01, and the feed becomes unavailable for KI-OL-02, KI-OL-03, and KI-OL-04. This doesn't reflect reality - the circuit breaker physically supplies power to all four outlets simultaneously.

Current Workaround (Doesn't Work)

The only workaround would be to create separate power feeds for each outlet:

• F12-Kitchen-Outlets-Port1
• F12-Kitchen-Outlets-Port2
• F12-Kitchen-Outlets-Port3
• F12-Kitchen-Outlets-Port4

But this is incorrect modeling because:

1. There's only ONE physical circuit breaker, not four
2. All four outlets share the same 16A capacity (not 16A each)
3. Power utilization tracking would be wrong - the circuit could be overloaded even if each "feed" shows under 80%

Proposed Solution

Power feeds should support one-to-many connections to device power ports, similar to how a network switch port can connect to multiple downstream devices through different cables.

This would allow accurate modeling of:

• Residential installations: One circuit breaker → multiple wall outlets → devices
• Small office/home office (SOHO): One circuit breaker → multiple workstations
• Industrial panels: One circuit breaker → multiple machines in a work area
• Extended datacenter scenarios: Main circuit breaker → distribution panel → multiple rack PDUs

Benefits

1. Accurate topology: Reflects real electrical distribution in homes, offices, and industrial settings
2. Proper power tracking: Total load on circuit breaker = sum of all connected devices across all outlets
3. Better capacity planning: Shows when a circuit is approaching its amperage limit across all connected outlets
4. Realistic modeling: Matches how electricians actually wire buildings
5. Compliance tracking: Helps ensure circuits don't exceed rated capacity

Example Hierarchy

Power Panel (Apartment Distribution Panel)
  └─ Power Feed: F12-Kitchen-Outlets (16A Circuit Breaker)
      ├─ KI-OL-01 Power Port → KI-OL-01 Outlet → Refrigerator (300W)
      ├─ KI-OL-02 Power Port → KI-OL-02 Outlet → Power Strip → Coffee Maker (1000W) + Toaster (800W)
      ├─ KI-OL-03 Power Port → KI-OL-03 Outlet → Dishwasher (1800W)
      └─ KI-OL-04 Power Port → KI-OL-04 Outlet → Microwave (1200W)
      
Total load on F12-Kitchen-Outlets: 5100W (22A @ 230V) → Circuit overload warning!

Database changes

Modification to the power feed cable termination logic to support multiple connections. The CableTermination model or power feed relationship would need to support one-to-many instead of one-to-one.

External dependencies

None

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Related Discussion: This issue relates to the unanswered question by @CvR42 in Discussion #12912:

"Power feeds as something that has a circuit breaker makes absolute sense to me, but then why is there the restriction to allow only one connection to a power feed? Real-world wiring normally doesn't have that restriction."

The current datacenter model (one feed → one PDU → multiple outlets) works for that specific use case, but residential and small office installations are structured differently and are equally valid to model in NetBox.