UL-291:2012 pdf free download – STANDARD FOR SAFETY Automated Teller Systems.
5.6.6 Where the starting or restarting of a motor driving a moving part such as described in 5.6.3 is provided by an automatic cycling device such as an overcurrent device or thermal protector, the requirement of 5.6.3 will require the use of a guard if the part is exposed when making operating adjustments or changing replaceable parts or if the part is accessible without requiring the use of tools.
5.6.7 With reference to 5.6.6, the scroll of a centrifugal blower may be used as a guard for the blower wheel.
5.6.8 If any part of the external enclosure of a product must be removed for operator servicing, that part shall be removed before the product is examined in connection with the requirement in 5.6.1.
5.6.9 The following parts may be used for securing doors, covers, and panels that are not opened or removed for operator servicing if supplementary guards or similar parts are provided as described in 14.1 — 14.3:
a) Thumbscrews;
b) Finger latches;
c) Screwdriver-, wrench-, and coin-operated latches;
d) Magnetic and spring latches that cannot be accidentally bumped open; and
e) Similar parts that result in reliable holding of a door or cover or support of a panel.
5.6.10 Panels as described in 5.6.9 are not to be opened or removed for the application of the probes mentioned in 5.6.4 and 5.6.5 in connection with the investigation of the accessibility of live or hazardous parts. See also 5.6.7.
5.6.11 In the enclosure of a unit an opening that does not permit entrance of 3/4-inch (19.1-mm) diameter rod may be used if a probe as illustrated in:
a) Figure 5.6 cannot be made to touch any uninsulated live part or hazardous moving part while inserted through the opening and
b) Figure 5.7 cannot be made to touch film-coated wire while inserted through the opening.
An opening that permits entrance of a 3/4-inch diameter rod may be used under the conditions described in 5.6.6. See Figure 5.8.
5.6.12 The opening illustrated in Figure 5.8 may be used if, within the enclosure, there is no uninsulated live part or film-coated wire:
a) Less than “X” inches from the perimeter of the opening, as well as
b) Within the volume generated by projecting the perimeter “X” inches normal to its plane.
“X” equals five times the diameter of the largest-diameter rod that can be inserted through the opening, but is not less than 4 inches (102 mm). In evaluating an opening, any barrier located within the volume is to be ignored unless it intersects the boundaries of the volume in a continuous closed line.
5.7 Interlocks and protective devices
5.7.1 An interlock provided for the purpose of protecting an operator or serviceman against injury or electric shock shall be of a type or in such a location that it requires an intentional operation to bypass.
5.7.2 The bypass means shall be such that the interlock is self-restoring as the unit is returned to its intended operation.
5.7.3 A protective device provided to remove a stored-energy charge from an internal circuit shall operate automatically when the circuit is de-energized.
5.8 Covers
5.8.1 An enclosure cover shall be hinged, sliding, pivoted or similarly attached so as to prevent its being removed if it.