UL 372:2007 pdf download – Automatic Electrical Controls for Household and Similar Use一Part 2: Particular Requirements for Burner lgnition Systems and Components.
17.16.1 05A Addition of requirements covering continuous lockout for electromechanical controls and the method of test:
Tests may be conducted with a new sample.
Timings shall not be adversely affected by prolonged energization of the lockout means.
One of the devices tested for compliance with clause 15, Manufacturer Deviation and Drift, shall be installed in an unheated test chamber and protected from drafts and extraneous sources of heat. The device shall be energized at 1.1 for 48 hours.
At the end of this period, the device shall be deenergized for at least 1 hour. The lockout timing shall then be determined as specified in item C of 15.5. The readings shall not exceed the manufacturers specified maximum Lockout Time (Table 7.2 item 114).
17.16.106 Test for particular purpose controls (See 29A, Constructio&Pedormance for Pilot Burners, Oxygen Depletion Safety Shutoff Systems (DS) and Other Components.)
17.16.106.1 Not Applicable.
17.16.107 Electric strength requirements
After the tests of 17.16.101 to 17.16.105A, the requirements of 13.2 shall apply, with the excephon mat the samples are not subjected to the humidity treatment before the application of the test voltage.
17.16.108 Evaluation of compliance
After completion of all the applicable tests of 17.16.101 to 17.16.107 inclusive, the sample shall be retested according to Clause 15. Manufacturer Deviation and Drift. The operating times. operating sequence, flame detector characteristics and proved igniter operating value shall be as declared in Table 7.2.
18 Mechanical strength
18.1 General requirements
18.2 Impact resistance
18.2.1 For independently mounted controls, except as provided in 18.4 are checked by applying blows to the sample by means 01 the apparatus in IEC 60068-2-75. Environmental testing — Part 2-75: Tests Eh:
Hammer tests, or the Standard for Polymeric Materials — Use in Electrical Equipment Evaluations UL 746C, or CSA C22.2 No. 0.17. the Standard for Evaluation of Properties of Polymeric Materials.
The impact resistance of controls constructed of polymeric materials is determined during test in UL 746C or CAhLCSA C22.2 No. 0.17. The impact resistance of controls constructed of metallic materials is determined as indicated in 18.4.
18.4 Alternate compliance — Impact resistance
18.4A Addition:
A sheet-steel transformer enclosure shall have a thickness of not less than 0.026 inch (0.66 mm) If uncoated and not less than 0.029 Inch (0.74 mm) If galvanized.
18.4A.1 Addition:
Sheet steel having a thickness of not less than 0.020 inch (0.51 mm) if uncoated and not less than 0.023 inch (0.58 mm) if galvanized may be used for a drawn end bell having maximum dimensions of 2-14 Inches (57.2 mm) on the flat portIon and 1-1/2 inches (38.1 mm) at the base of the drawn portion.
Table 18.4.1 ModIfy the notes to Table 18.4.1 in the Part 1 as follows:
At points at which a wiring system is to be connected, uncoated steel shall not be less than 0.032 Inch (0.81 mm) thick, zinc-coated steel shall not be less than 0.034 Inch (0.86 mm) thick,
Table 18.4.2 ModIfy the notes to Table 18.4.2 in the Part I as follows:
At points at which a wiring system is to be connected, nonferrous metal shall not be less than 0.045 Inch (1.14 mm) thick.
18.5 through 18,8 Not App1icabe
18.9 ActuatIng member and actuating means
189.1 through 189.3 Not Applicable.
18.9A Addition:
For a control that is operated by a push, pull, slide, toggle, or lever adjustment, a force Is to be applied to the hoe end of the adjustment in line with the intended movement in each direction of operation. The force is to be 20 pounds (89 N) for a commercial or industrial control and 10 pounds (45 N) for a residential control. A separate sample Is to be used for each test.
18.9A.1 A control adjustment operated as described In paragraph 18.9A and intended for use with an extended operator, handle, or lever is to be tested with an in-line force applied to the free end of an extension representing the intended end-use application.
18.9A.2 For a control that is operated by a rotary adjustment intended for use with a knob having a grip diameter or grip length of 1 inch (25.4 mm) or less, a torque is to be applied to the shaft In each direction of intended operation. The torque is to be 9 pound-inches (1.0 Nm) for a commercial or industrial control and 7 pound-inches (0.8 Nm) for a residentIal control. A separate sample Is to be used for each test.