30 Days Load Study (NEC 220.87) in Bay Area
What Is a 30-Day Load Study?
Instead of estimating based on connected loads, we measure real usage over 30 days using a professional data logger.
This allows engineers, contractors, and inspectors to verify if an existing service can safely support new equipment or additional circuits — without the need for a full panel upgrade.
This allows engineers, contractors, and inspectors to verify if an existing service can safely support new equipment or additional circuits — without the need for a full panel upgrade.
Important to know
When a Load Study Is Required?
600 Amp Switchboard
30 days load study
A 30-day load study is typically required for:
Commercial buildings – offices, restaurants, warehouses, retail stores
Large residential properties – homes with 400A+ service or accessory units (ADUs)
Projects involving added electrical load, such as:
Commercial buildings – offices, restaurants, warehouses, retail stores
Large residential properties – homes with 400A+ service or accessory units (ADUs)
Projects involving added electrical load, such as:
- EV charger installations
- HVAC or heat pump upgrades
- New machinery or commercial kitchen equipment
- Tenant improvements (TI) and service upgrades
- City inspectors and PG&E often request a load study report before approving permits for these upgrades.
Why it matters?
Why It Matters (NEC 220.87 Compliance)?
According to NEC 220.87, you can verify service capacity by documenting the maximum demand over a 30-day period.
This approach ensures compliance with national standards and helps avoid unnecessary service replacements.
Without proper monitoring, you risk:
This approach ensures compliance with national standards and helps avoid unnecessary service replacements.
Without proper monitoring, you risk:
- Overloaded circuits and voltage drops
- Rejected permit applications
- Unnecessary expenses on oversized service upgrades
Architecture request
A new kitchen must be built based on the results of the 30-day load study.
How does it work?
Our Process
Here are a few steps to ensure a safe completion.
- Site Evaluation – We inspect your main panel and determine monitoring points.
- Data Logger Installation – We install a certified logger to record amps, voltage, and demand over 30 days.
- Monitoring Period – The system tracks real-time usage 24/7 under normal operating conditions.
- Report Generation – After 30 days, we analyze the data and prepare a detailed report compliant with NEC 220.87.
- Permit Support – The report is accepted by local jurisdictions, PG&E, and building departments.
An Example!
Before & After
Schedule Your NEC 220.87 Load Study
Ensure your service meets code and capacity requirements before upgrading equipment or applying for permits.
- Before:A commercial property planned to install a 30 kW rooftop HVAC system. The city requested proof that the existing 400 A service could handle the added load.
- After:Haxx Heating, Air & Electrical performed a 30-day load study. The report showed the building’s peak demand was only 230 A — leaving enough capacity for the new unit. The city approved the project without requiring a panel upgrade.
- NEC 220.87 compliant
- Permit approved
- No unnecessary upgrade cost
Why Choose a Licensed Electrician in the Bay Area?
As a local company, we treat every client like a neighbor and every business like our own.
- Licensed & Insured C-10 Electrical Contractor
- Load study reports fully NEC 220.87 compliant
- Accepted by PG&E, City of San Jose, and other Bay Area jurisdictions
- Ideal for commercial properties and large residential systems
- Accurate data logging with no power interruption
FAQ
Bay Area Homeowners Ask Us All the Time
Only for large residential systems (typically 400 A and above) or when required by city inspectors for additional loads.
Yes, most commercial service upgrades or load additions require a 30-day load study per NEC 220.87.
Prices typically depending on service size, monitoring complexity, and access.
No — installation is quick and doesn’t interrupt electrical service.