400-Amp Overhead Service Upgrade & Sub-Panel Replacement – 8-Unit Apartment Building • Los Angeles, CA
Project Snapshot
| Property Type | 8-unit, two-story apartment building |
|---|---|
| Existing Condition | Federal Pacific 200 A main & aging FPE sub-panels |
| Scope | Replace entire service and nine sub-panels |
| New Equipment | 9-gang 400 A Square D overhead service, (9) 12/24-circuit Square D sub-panels |
| Authority Coordination | LADWP Service Planning & Field Crew • LADBS Inspection |
Before – Old Federal Pacific meter bank
After – New 400 A 9-gang meter bank
Before – Painted-over FPE sub-panel
After – New Siemens sub-panel
1. Background & Challenge
The owner’s insurer flagged the building’s original Federal Pacific equipment as a fire hazard and threatened non-renewal unless it was replaced. In addition to safety concerns, the 200 A service left no capacity for future EV chargers or HVAC upgrades. The owner needed a fast, code-compliant solution that minimized tenant downtime.
2. Solution Overview
Branover Contractors engineered and installed a 400 A, 9-gang Square D overhead service—one meter per apartment plus a dedicated house meter—along with nine 12/24-circuit sub-panels mounted inside each unit.
Key design steps:
- Load Calculation & Single-Line Diagram
- Single-line & load calculation for confirmed 400 A capacity requirement.
- Single-line diagram and load calculation submitted to LADWP Service Planning.
- Utility Coordination
- Obtained meter spot approval within five business days.
- Scheduled with LADWP Field Crew to set new meters.
- Permit & Inspection
- Pulled electrical permit with LADBS.
- Passed electrical service and final inspections.
- Installation Highlights
- 3″ galvanized riser, new weatherhead, and 500 MCM copper conductors.
- Bonded & grounded.
- Sub-panels labeled and circuits re-terminated.
Phase Key Activities
1. Site Assessment & Engineering — Perform load calculations • Draft single-line diagram • Scope materials
2. Utility & Permit Approvals — Submit plans to LADWP for meter spot • Pull LADBS electrical permit
3. Pre-Construction Coordination — Schedule shutdown window with LADWP Field Crew • Notify tenants of brief, staggered outages
4. Demolition & Temporary Power — De-energize and remove Federal Pacific gear • Provide temporary feeds for essential circuits
5. Main Service Installation — Install 400 A 9-gang Square D meter stack, riser, weatherhead, conductors • Complete grounding & bonding
6. Sub-Panel Replacements — Swap nine 12/24-circuit sub-panels one unit at a time • Re-terminate and label branch circuits
7. Inspection & Re-Energization — Pass LADBS inspection • LADWP installs new meters and restores permanent power
4. Results & Benefits
- Safety & Compliance – Eliminated high-failure FPE gear; installation passed LADBS.
- Capacity for Growth – 400 A service future-proofs the building for solar, EV charging, or heat-pump retrofits.
- Insurance Savings – Owner secured renewal and avoided a 30 % premium surcharge.
- Property Value – Modern service infrastructure is a selling point for prospective buyers and tenants.
- Tenant Experience – Planned outages communicated in advance; no reported appliance damage or lost rent days.
5. Key Takeaways
- One-Stop Service – From design to final meter set, we streamline utility and city approvals.
- First-Time Inspection Passes – Thorough pre-inspection checklists mean no costly re-visits.
- Minimal Downtime – Phased sub-panel swaps keep tenants powered and happy.
- Future-Ready Designs – We size services for tomorrow’s loads, not yesterday’s
