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Subchapter 5. Electrical Safety Orders
Group 2. High-Voltage Electrical Safety Orders
Article 27. Transformers (Formerly Article 76)

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§2874. General.

(a) Ventilation. Adequate ventilation shall be provided to assure safe operating temperature of apparatus.
(b) Protection from Physical Damage. Transformers and attachments, such as conductors and externally mounted devices, shall be protected from physical damage by suitable barriers, guards, or location.
(c) Identification. Each transformer shall be identified by a permanent nameplate which includes the following information:
(1) The word(s) “Transformer,” “Voltage Regulating Transformer,” or “Voltage Regulator.”
(2) Manufacturer's name, type, and serial designation.
(3) Rated KVA, phases, and frequency.
(4) Voltage ratings and tap voltages.
(5) Connection diagram.
(6) Polarity (single phase).
(7) Impedance.
(8) Rated temperature rise in degrees centigrade.
(9) Identification of insulating medium.
(10) Amount of insulating liquid (not required for sizes 167 KVA and smaller).
(11) Approximate total weight (not required for sizes 25 KVA and smaller).
(d) Access Openings. Access openings to transformer enclosures shall be provided with a means for locking or otherwise preventing unauthorized access.
(e) Signs.
(1) A permanent, legible, and clearly visible “HIGH VOLTAGE” warning sign, having letters at least 2 inches high, shall be located on the access opening of each transformer enclosure. These signs shall read substantially as follows: “Danger-High Voltage - Keep Out.”
(2) The operating voltage of exposed live parts of transformer installations shall be indicated by signs or visible markings on the equipment or structure.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
1. Editorial correction filed 11-2-83 (Register 83, No. 45).
2. Amendment filed 12-10-87; operative 1-9-88 (Register 88, No. 1).
3. Amendment of section and Note filed 4-1-2009; operative 4-1-2009. Submitted to OAL for printing only pursuant to Labor Code section 142.3 (Register 2009, No. 14).

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