UL 140:2018-07 Relocking Devices for Safes and Vaults.
1.1 These requirements cover relocking devices for the following:
a) Light vault doors,
b) Heavy vault doors, and
c) Safes or chests.
1.2 Relocking devices are intended to relock the bolt mechanism or door of a vault, safe, or chest in the event that the combination lock is subjected to attack.
1.3 A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involve a risk of fire, electric shock, or injury to persons shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard cannot be judged to comply with this standard. Where considered appropriate, revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.
2.1.1 Except as indicated in 2.1.2, a component of a product covered by this standard shall comply with the requirements for that component.
2.1.2 A component is not required to comply with a specific requirement that:
a) Involves a feature or characteristic not required in the application of the component in the product covered by this standard or
b) Is superseded by a requirement in this standard.
2.1.3 A component shall be used in accordance with its recognized rating established for the intended conditions of use.
2.1.4 Specific components are recognized as being incomplete in construction features or restricted in performance capabilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specified limits, and shall be used only under those specific conditions for which they have been recognized.
UL 140 pdf download.