The requirements on this page are for installation of all or part of a stationary, hard-wired generator system. A mechanical and an electrical permit with plan documentation must be submitted before work can begin. A building permit is required when building alterations or additions are anticipated, including but not limited to construction of new exhaust or supply-air shafts, new exterior wall openings, new equipment screens, or if the generator and/or fuel tank is required to be in a separated fire-resistance rated room.
Your application and plans will be reviewed by Mechanical, Electrical, Fire, Building and Land Use planners to ensure all applicable code provisions are met.
Mechanical Permit Submittal Requirements
- A scaled site plan showing the location of all buildings on the site and the generator location (interior or exterior) with setbacks to property lines clearly shown. Streets, alleys, easements, fences, gates and a north arrow must be shown.
- If the generator will be located inside the building, provide calculations showing compliance with the manufacturer's installation requirements for ventilation supply, exhaust, engine cooling and combustion-air openings. Provide scaled interior and exterior elevation views showing the location of the generator, ventilation openings (both supply and exhaust), fuel tank vent(s) and the engine exhaust pipe terminal.
- Plans showing the fuel source, tank size and location (if applicable), fuel pipe routes (with minimum required slope noted), generator refueling station location, and pipe size and materials. Fuel oil piping to generator must comply with IMC Chapter 13.
- If located inside the building, specify on which level of the building the generator and fuel tank are located.
- Manufacturer's data sheets on the generator, fuel tank, refueling station and other equipment to be used in the installation.
- Physical protection of equipment must be detailed on the plans if the generator fuel tank is located outside. (IMC Section 1305.2)
- Fuel tank manufacturer’s UL listing, single wall or double wall, and size. Specify use of all openings for the fuel tank.
- Information on spill control, secondary containment and drainage.
See also NFPA 37, which is referenced from IMC Section 915.
Electrical Permit Submittal Requirements
- Load summary, including each step of load (what loads are transferred to the generator at any one time) in starting and running (separate columns totaled) to verify capacity.
- Location of transfer switches for the emergency and legally required systems.
- What equipment is on which transfer switch and how long of a delay is allowed for each piece of equipment to come on after the normal power is off.
- Physical protection of the circuit wiring for pressurization fans and fire pumps from the generator to the fan(s) and pumps.
- Sizing of the generator conductors between the generator and first over-current device.
- One line or riser diagram showing the connections to the electrical system, conduit and wire sizes, transfer switch characteristics and generator sizing.
See also the “2007 Emergency Power Supply Systems – Generators Reminder List” for applicable codes and standards.
Building Permit Submittal Requirements
Common building code issues associated with generator installations:
- Seismic/gravity anchoring and support per ASCE 7-05 Section 13.1.3. Refer to Seismic Bracing Matrix document for more information.
- Not less than a 1-hour fire barrier is required if the building has a smoke control system per IBC Section 909.11. For high-rise buildings an emergency power system and automatic transfer switch (ATS), if set inside the building, must be located in a separate room enclosed with 2-hour fire barriers. IBC Section 403.10.1.
- Control and power wiring serving shaft pressurization fans must be provided with 2-hour fire-rated protection. Illustrate this on the building plans. See IBC Section 9220.127.116.11.
- Where an on-site, stand-alone fuel storage tank is provided, the size, type, and location must be identified. The applicant must specify occupancy classification for on-site fuel storage.
- For legally required generators: Combustion, cooling, and ventilation air needs to be from an exterior wall opening without self-closing dampers, shutters or other devices. NFPA 110 Section 7.7 and IBC Section 909.11.
- Equipment screen and platform design details, if applicable, must be provided for review.
- Shafts used to provide exhaust, combustion air and/or make-up air must comply with IBC Section 707. Complete shaft assembly listing numbers and associated details must be provided.
Land Use Submittal Requirements
- The ventilation openings and engine exhaust pipes, when visible from the street, need to be designed in a manner that will not detract from the building design.
- All residential mechanical equipment installation must conform to the City of Bellevue Noise Code Standards: Day 55dBA – Night 45dBA.
- Elevation sheet to scale showing height of all equipment (existing and proposed), screening and/or landscaping, and color of screening and equipment if located in a design district.
- If located in a design district or a project that required an Administrative or full Conditional Use permit, a separate Land Use Exemption permit is required.
Fire Department Submittal Requirements
Diesel and propane generators or power system at any location is covered in the Fire Code and NFPA Standards. Common fire code issues associated with generator installation:
- Class I, II (diesel), and IIIA flammable and combustible liquid fuel systems are covered in IFC Chapters 50 & 57.
- Venting of fuel tanks must comply with IFC 5703 and IMC Chapter 13.
- Refueling of Class I, II, and IIIA tanks covered in IFC Section 5704.
- Emergency and standby power systems covered in IFC Section 1203.
- Fuel fired appliances covered in IFC Section 603.
- Propane Tanks covered in IFC Chapter 61.
- Fuel capacity driven by the requirements for fire pumps -- NFPA 20 Section 18.104.22.168.
- Containment requirements are found in IBC 415, IFC Chapters 50 & 57.
- Propane tanks must be located in accordance with IFC Chapter 61.
Note: A Fire Department Operational Permit is required before any propane tank can be filled (IFC 105.6). Exception: R-3 occupancy with tanks of 500 gallons or less.