Any provision of the National Electrical Code adopted by Section 9-101 of this Subtitle shall be subject to change, modification, addition or omission as set out in Subdivision 2, and such change, amendment, addition or deletion shall be deemed to supersede the text of the Electrical Code in any case where the provisions of this Subtitle are interpreted.

The following amendments, additions, and/or deletions are made to Section 110.26 of the National Electrical Code: Section 110.26(D), "Illumination," is amended to read as follows: In addition to Article 110.26(D) and Emergency Illumination, Section 700.16, in all commercial occupancies, a wall mounted battery pack operated emergency illumination shall be provided for all working spaces about service equipment, switchboards, panelboards, load centers and motor control centers installed indoors. The battery shall be of suitable rating and capacity to supply and maintain the total load for a minimum period of 2 hours.

For residential and commercial applications, in locations where electrical equipment is likely to be exposed to physical damage by vehicles, electrical equipment shall have vehicle impact protection per 2021 International Building Code ("IBC") 1607.10, or as per 2021 International Residential Code ("IRC") E3404.10.

The following amendments, additions, and/or deletions are made to Article 250 of the National Electrical Section 250.52(A)(1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductor(s) or jumper(s), if installed. Grounding electrode conductor shall be bonded to water pipe within 5 feet of where cold water pipe enters the structure. Section 250.52(A)(2) Metal In-ground Support Structure(s). One or more metal in-ground support structure(s) in direct contact with the earth vertically, with or without concrete encasement. If multiple metal in-ground support structures are present at a building or a structure, it shall be permissible to bond only one into the grounding electrode system. Informational Note: Metal in-ground support structures include, but are not limited to, pilings, casings, and other structural metal. Section 250.52(A)(3), "Concrete - Encased Electrode," is amended to read as follows: All new structures, both residential and commercial, require a concrete encased electrode to be used as the principal grounding electrode system.

The following amendments, additions, and/or deletions are made to Article 310 of the National Electrical Code: The following paragraph is added to Section 310.10, "Uses Permitted:" (C) Aluminum or copper-clad aluminum conductors. Aluminum or copper-clad aluminum conductors shall be permitted only for service and feeder use and shall not be smaller than #2 AWG. The following exception is added to Section 310.10, "Uses Permitted:" Listed Cable assemblies #2 aluminum or copper-clad aluminum conductors AWG and larger installed in single-family and multifamily dwellings, having grounding conductors sized in accordance with Section 250.122, "Size of Equipment Grounding Conductors," shall be excluded from the requirements set forth in (a)(l), above.

The following amendments, addition, and/or deletion are made to National Electrical Code article 110.3, 110.3(B). The use of the Non-UL listed SMA and any other manufacturer Power Supply/PV Inverters is NOT approved for installation in Prince George's County. This determination has been made after working with Underwriters Laboratories (UL). Until acceptable evidence that overcurrent protection of the circuit is provided, as required by UL 1741 and UL1699B, Section 30.3, as well as with articles of NFPA 70, including Article 110.3(B).

The following amendments, additions, and/or deletions are made to Article 408 of the National Electrical Code: All commercially owned occupancies including dwelling units having electrical equipment with a capacity of eight hundred (800) amperes or larger, shall undergo maintenance, cleaning and inspection as described by the manufacturer: every three (3) years by a master electrician licensed by Prince George's County. The master electrician must promptly prepare a written maintenance report identifying the equipment inspected and cleaned including any conditions to be corrected and or repaired. A copy of the report shall be delivered to the owner within in 10 days of the inspection. Any deficiencies noted thereon must be corrected or repaired. Moreover, a copy of the "Maintenance/Cleaning Inspection Report shall be made available to the Department of Permitting and Inspections upon request. If such maintenance or cleaning requires a coordinated shut down with the servicing utility company, an electrical permit shall be required. The maintenance and cleaning includes but is not limited to the following: Vacuum entire interior of electrical equipment; Clean busbars and contacts with a suitable nonconductive solvent; Lubricate and exercise all moving mechanisms; apply anti-oxidizing agents as warranted; Check all conductors for abrasions; Busbars and busbar connections shall be subjected to thermographic testing, if corrective action is warranted, repair shall be made in accordance with recommended manufacturer specifications; Replace worn, damaged, or deteriorating components; and Test ground-fault protective device. Testing and cleaning records shall be kept and made available upon request and proper antioxidizing agents shall be used after each cleaning. On all new and renovated installations requiring service and distribution electrical equipment, Electrical Contractor shall provide a Letter from utility company stating the short circuit available interrupting current (SC AIC) rating required for the service equipment to inspector at the TPF inspection. Upon final inspection of all electrical work the electrical contractor shall provide letter certification of electrical connection tightening per manufacturer requirements and recommendations.

The following amendments, additions, and/or deletions are made to Article 408 of the National Electrical Code: Article 408.36, "Overcurrent Protection," Exception No. 2 is amended to read as follows: For existing installations, split-bus panelboards shall be required to be replaced by a main over-current protective device panelboard when replacement of service entrance conductors occurs.

The following amendments, additions, and/or deletions are made to Article 410 of the National Electrical Code: The following addition is made to paragraph (B) of Section 410.36: All "lay-in" luminaires will require independent suspension to ensure that the luminaire will not drop more than nominally two (2) or three (3) inches when the framing members no longer provide the support. Number 12 WG wire firmly secured to the building structure and the luminaire is required for this purpose. Two (2) restraining wires (one (1) at each opposite end of the luminaire) are required for luminaries smaller than 2×4 and four (4) restraining wires (one (1) at each corner) are required on all luminaries 2×4 and larger. Other types of lay-in fixtures and surface mounted fixtures mounted on drop ceiling shall be support based on the fixture area to preclude the danger of falling when the framing members fail or are removed (e.g., hi-hat luminaire). A state certified modular building is subject to comply with MPC (Model Performance Code), COMAR 09.12.50 only and is not subject to local ordinances. The installation of the luminaires and inspection of same shall be completed at the factory and shall be done in accordance with the MPC therefore it would not be subject to local amendments.

The following amendments, additions, and/or deletions are made to Article 410 of the National Electrical Code: The following addition is made to paragraph (B) of Section 410.36: All "lay-in" luminaires will require independent suspension to ensure that the luminaire will not drop more than nominally two (2) or three (3) inches when the framing members no longer provide the support. Number 12 WG wire firmly secured to the building structure and the luminaire is required for this purpose. Two (2) restraining wires (one (1) at each opposite end of the luminaire) are required for luminaries smaller than 2×4 and four (4) restraining wires (one (1) at each corner) are required on all luminaries 2×4 and larger. Other types of lay-in fixtures and surface mounted fixtures mounted on drop ceiling shall be support based on the fixture area to preclude the danger of falling when the framing members fail or are removed (e.g., hi-hat luminaire).

The following amendments, additions, and/or deletions are made to Article 450 of the National Electrical Code: The following paragraph is added to Section 450.14: A means of disconnecting the primary shall be located "within sight" of any dry-type transformer meeting the requirements of 450.21(A), (B), and (C).

The following amendments, additions, and/or deletions are made to Article 700 of the National Electrical Code: Section 700.5(A) is amended by the addition of the following sentence: All Emergency Systems such as panelboards, motor control centers, load centers, disconnects, transformer and Transfer equipment shall be separated from normal power distribution system by a wall or wall(s) with a minimum fire rating of two (2) hour(s).

The following amendments and/or additions are made to Article 700 of the National Electrical Code. A connection ahead of service disconnecting means is not permitted as an emergency circuit except as permitted by Section 9-109.01 of this Code.

The following amendments, and/or additions are made to Article 695 of the National Electrical Code: A fire pump shall be supplied by a separate service from the utility transformer. A fire pump shall be permitted to be supplied from a connection located ahead of the service disconnecting means when a back-up on-site generator is used as an alternate power source to feed the fire pump. Electrical requirements for Diesel Fire Pump Controller Power Source per NFPA20: Diesel Fire Pump controller shall be connected to the emergency power source such as standby emergency generator. If there is no Standby Emergency Generator, Diesel Fire Pump Controller shall be permitted to be supplied from the battery. There are two storage battery units shall be provided and rack-supported above the floor, secured against displacement, and located where they are readily accessible for servicing and not subject to excessive temperature, vibration, mechanical injury, or flooding. Storage battery units shall be provided with battery chargers specifically listed for fire pump service, arranged to automatically charge at the maximum rate whenever required by the state of charge of the battery, and arranged to indicate loss of current. For diesel driven fire pumps, verify that the following alarms related to battery are provided on the controller and operative: Battery failure/battery missing; Battery charger failure.