SF Electrical Code interpretations

January 1, 2023

The following are guidelines to Electrical Inspection staff. 

Purpose: To provide consistent application of the requirements for Laundry Areas.
Question: Is it required by code to install a Dedicated Single Phase 125 Volt 20 Amp Laundry Circuit and Receptacle Outlet when the Specified Washer, Dryer, or Combo Washer & Dryer, Electrical Specification is different?
Response: Yes. Any Other Laundry Equipment that has an Electrical Specification that is different must follow the Manufactures Installation Instructions and would be in addition to the code requirements.
Reference: 2022 California Electrical Code (2020 NEC)

  • 210.11(C) Laundry Branch Circuits. In addition to the number of branch circuits required by other parts of this section, at least one additional 20-ampere branch circuit shall be provided to supply the laundry receptacle outlet(s) required by 210.52(F). This circuit shall have no other outlets.
  • 210.52 Dwelling Unit Receptacle Outlets. This section provides requirements for 125-volt, 15- and 20-ampere receptacle outlets.
  • 210.52(F) Laundry Areas. In dwelling units, at least one receptacle outlet shall be installed in areas designated for the installation of laundry equipment.
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Interpretation #2: Protection from physical damage

Purpose: To provide consistent application of the requirements for MC Cable in Dedicated Electrical Rooms.

Question: Shall Type MC Cable, #4 AWG or larger, be considered protected from physical damage when installed in a lockable room dedicated to electrical service and distribution equipment and accessible only to qualified personnel?

Response: Yes.

Reference: 2022 California Electrical Code (CEC) (2020 NEC) Article 330.12 & 2022 San
Francisco Electrical Code (SFEC) Article 330.12 & 300.4(I)

Existing Text: Section 330.12 Uses Not Permitted. Type MC Cable shall not be used under either of the following conditions:

1. Where Subject to Physical Damage.

Informational Note: 2022 San Francisco Electrical Code Section 300.4 (I) Subject to Physical Damage. Premises wiring systems installed less than 2.44 m (8 feet) above a walking surface or finished floor are considered subject to physical damage.

2022 SFEC Exception: Type MC Cable #4 AWG or larger, installed in a lockable room dedicated solely to an electrical service and distribution equipment and accessible only to qualified personnel, shall be considered to have equivalent protection from physical damage when installed in a neat and workman like manner, properly supported, and securely fastened in place.

2. Where exposed to any of the destructive corrosive conditions in (a) or (b), unless the metallic sheath or armor is resistant to the conditions or is protected by material resistant to the conditions:

a. Direct buried in the earth or embedded in concrete unless identified for direct Burial.

b. Exposed to cinder fills, strong chlorides, caustic alkalis, or vapors of chlorine or of hydrochloric acids.

Purpose: To provide guidelines for the installation of transformers 1000 volts nominal or less and not exceeding 50kva when suitable floor or wall space is not available.

Question: Can Transformers 50 kVa or Less be mounted above a T-Bar Ceilings or Hard Lid Ceilings with Access Doors.

Response: Yes.

Reference: 2022 California Electrical Code (CEC) 450.13(B) Hollow Space Installations; 450.14 Disconnecting Means; 300.22 (C) Other Spaces Used for Environmental Air
(Plenum); 110.13 Mounting and Cooling of Equipment; 110.25 Lockable Disconnecting Means.

Existing Text: 450.13 (B) Hollow Space Installations. Dry-type transformers 1000 volts, nominal, or less and not exceeding 50 kVA shall be permitted in hollow spaces of buildings not permanently closed in by structure, provided they meet the ventilation requirements of 450.9 and separation from combustible materials requirements of 450.21(A). Transformers so installed shall not be required to be readily accessible. 

Additional Provisions:

In addition to the requirements of Section 450.13 above, the following shall apply:

  1. Provide adequate access to, and workspace at, the transformer.
  2. Provide mounting, support, and longitudinal & lateral bracing in accordance with the applicable Section of the San Francisco Building Code for suspended installations.
  3. Provide an externally operated disconnect switch in sight of the transformer or in a remote location. Where located in a remote location, the disconnecting means shall be lockable in accordance with 110.25, and its location shall be field marked on the transformer.
  4. Provide permanent and durable signage at or adjacent to the transformer that reads as follows: DANGER, DISCONNECT SUPPLY POWER BEFORE REMOVING THE TRANSFORMER TERMINATION COVER.
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Interpretation #4: Rigid Polyvinyl Chloride Conduit: Type PVC

Purpose: To provide consistent application of the requirements for PVC Conduit.

Question: Is PVC Conduit permitted for exposed work?

Response: No

Reference: 2022 San Francisco Electrical Code (SFEC) (2022 NEC) Article 352 Rigid Polyvinyl Chloride Conduit: Type PVC

  • 352.10 Uses Permitted. The use of PVC conduit shall be permitted in accordance with 352.10(A) through (I). Informational Note: Extreme cold may cause some nonmetallic conduits to become brittle and, therefore, more susceptible to damage from physical contact.
  • 2020 NEC (A) Concealed. PVC conduit shall be permitted in walls, floors, and ceilings.
  • 2022 SFEC (A) Concealed: PVC conduit shall be permitted to be embedded in concrete. The conduit may emerge not more than 3 inches from the concrete within wiring enclosures, otherwise metal raceways shall be provided where emerging from the concrete.
  • 2020 NEC (F) Exposed. PVC conduit shall be permitted for exposed work. PVC conduit used exposed in areas of physical damage shall be identified for the use. Informational Note: PVC Conduit, Type Schedule 80, is identified for areas of physical damage.
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Interpretation #5: Sizing Conductors for Single-Phase Dwelling Services and Feeders

2022 San Francisco Electrical Code (SFEC) 2020 NEC 310.12 Single-Phase Dwelling Services and Feeders Interpretation #5

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