(1) This section applies to the installation of all transformers.
Exceptions: | 1. Current transformers; |
| 2. Dry-type transformers installed as a component part of other apparatus; |
| 3. Transformers that are an integral part of a high frequency or electrostatic-coating apparatus; |
| 4. Transformers used with Class 2 and Class 3 circuits, sign and outline lighting, electric discharge lighting, and power-limited fire-protective signaling circuits; and |
| 5. Liquid-filled or dry-type transformers used for research, development, or testing, where effective safeguard arrangements are provided. |
(2) The operating voltage of exposed live parts of transformer installations must be indicated by warning signs or visible markings on the equipment or structure.
(3) Dry-type, high fire point liquid-insulated, and askarel-insulated transformers installed indoors and rated over 35kV must be in a vault.
(4) If they present a fire hazard to employees, oil-insulated transformers installed indoors must be in a vault.
(5) Combustible material, combustible buildings and parts of buildings, fire escapes, and door and window openings must be safeguarded from fires that may originate in oil-insulated transformers attached or adjacent to a building or combustible material.
(6) Transformer vaults must be constructed to contain fire and combustible liquids within the vault and to prevent unauthorized access. Locks and latches must be arranged so that a vault door can be readily opened from the inside.
(7) Any pipe or duct system foreign to the vault installation must not enter or pass through a transformer vault.
(8) Materials must not be stored in transformer vaults.
[Statutory Authority: RCW
49.17.010,
49.17.040,
49.17.050, and
49.17.060. WSR 20-21-091, § 296-307-36851, filed 10/20/20, effective 11/20/20. WSR 97-09-013, recodified as § 296-307-36851, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW
49.17.040, [49.17.]050 and [49.17.]060. WSR 96-22-048, § 296-306A-36851, filed 10/31/96, effective 12/1/96.]