UL 38:2008 pdf download – Manual Signaling Boxes for Fire Alarm Systems
UL 38:2008 pdf download – Manual Signaling Boxes for Fire Alarm Systems.
17.1.5 A combined fire alarm and watchman’s signahng box is first to be tested for 500 cycles of fire alarm signal operation under the conditions indicated in 17.1.3, and then for 4500 cycles of operation under the conditions indicated in 17.1.4.
17.1.6 The contacts of a coded signaling box that control only electromagnets used for noninterfering signals or for successive signals are to be subØcted to:
a) 50 cycles of operation with the overload resulting from operation at 115 percent of the rated current and
b) 450 cycles at rated current.
17.1.7 A non-coded signaling box is to be operated manually for 500 cycles of operation of each different set of switching contacts at the rate of 6 cycles per minute. Each cycle is to Consist of making and breaking 150 percent of Ihe rated current and at rated voltage.
17.1.8 The signaling box is to be tested either with the load (inductive or noninductive) that the contacts are intended to control or with an equivalent load (see 17.110 and 17.1.11). Also:
a) A box intended and marked for use on alternating current only is to be tested with alternating current,
b) A box intended for use on direct current and a box not specifically marked for altemating current only shall be tested with direct current.
C) A box with a single voltage rating and a single current rating is to be tested at that voltage and current.
d) A box with multiple voltage ratings and a single current rating is to be tested at the highest voltage indicated and at the current indicated.
e) A box with multiple current ratings is to be tested under conditions of maximum voltage.
power. and current inlerrupted. If the box has different current ratings for alternating Current and direct current, the box is to be tested for each rating. Separate samples are to be used for
testing at each different rating.
17.1.9 For alternating-current signaling circuits, an equivalent inductive test load is to have a power factor of 0.6 or less.
17.1.10 For direct-current signaling circuits, an equivalent inductive test load is to have the direct-current resistance needed to obtain the test current and the inductance (calibrated) needed to obtain a power factor of 0.6 when the load is connected to a 60-hertz rms potential equal to the rated direct-current test voltage. When the inductive load has both the required direct-current resistance and the required inductance, the current measured with the load connected to an altemating-current circuit will be equal to 0.6 times the current measured with the load connected to a direct-current circuit when the voltage of each circuit is the same.
17.1.11 The load is to be applied so as to obtain a potential difference of 240 volts between contacts that could be used in that manner.
17.1.12 A signaling box intended for use on circuits having one conductor grounded is to be tested with the enclosure connected through a 3-ampere cartridge fuse to the grounded conductor. If the box is intended for use on other types of circuits, the enclosure is to be connected through a similar fuse to the live pole least likely to strike ground.
17.2 Watchman’s suppressed-signaling tour devices
17.2.1 The watchman’s key or similar device and each different type of tour-station device shall withstand
6000 cycles of operation without being adversely affected. There shall not be malfunction of electrical and mechanical parts, undue wear of parts, or impaired operation of the key and station devices.
17.2.2 Each test cycle is to include operation of the key or similar device in:
a) A tour-starting. s*gnai-transmithng station;
b) ‘The first intermediate station:
c) Either all other intermediate stations or in a testing device that will position the key in the same manner as that obtained by operating it in the other stations; and
d) A tour-finishing, signal-transmitting station. 18 Jarnng Test
18.1 A signaling box shall withstand jarring resulting from impact and vibration, such as might be experienced in service, without causing signaling operation of any part and without impairing its subsequent operation.
18.2 The effects of jarring are to be determined by supporting the box in the position of intended use at the center of a 6 by 4 loot (1.8 by 1.2 m). 3/4-inch (19.1-mm) thick plywood board secured in place at four corners, A 3 foot-pound (4.08 J) impact is to be applied to the center of the reverse side of this board. This impact is to be applied by means of a 1.18 pound (0.54 kg), 2-inch (51-mm) diameter steel sphere swung through a pendulum arc from a height (h) of 254 feet (775 mm) to apply 3 foot-pounds of energy. The signaling contacts are to be connected in series with an indicating lamp across a power source as a means of indicating false operation. See Figure 18.1.