Army Electrical Explosives Safety (Ammo-28) Questions And Answers Which two publications provide detailed information on lightning protection systems? ✔️Ans - DA PAM 385-64
NFPA 780
Which statements about lightning protection are true?Select all that apply.✔️Ans - Lightning can detonate munitions and explosives.Lightning seeks the path of least resistance to ground.Lightning cannot be stopped or prevented.Which statement is true about a mast LPS? ✔️Ans - Each mast must have two paths to ground.A 30-foot tall building is protected by a catenary system. How far from the building should the masts be placed? ✔️Ans - at least 6 feet Which LPS uses air terminals and conductors mounted directly to the structure? ✔️Ans - Integral Why does the wooden mast have an air terminal on top and two down conductors running its entire length? ✔️Ans - The wooden mast is not electrically conductive Which of the following is NOT a requirement for air terminals? ✔️Ans - Air Terminals must be at least 6 feet tall.During the inspection, John's team logged a discrepancy for this air terminal.Why? ✔️Ans - The air terminal is not attached to a conductor.How many down conductors are required for a building with a perimeter length of 325 feet? ✔️Ans - 4 While conducting an LPS inspection, you see mast down conductors routed as shown in the image below. Do you write it up as a discrepancy? Why or why 1 / 2
not? ✔️Ans - Yes, because mast down conductors should be 180 degrees apart.A steel beam, connected to the main LPS at its upper and lower extremities, is used as a down conductor. At what intervals should it be connected to the grounding system? ✔️Ans - 60 feet or less Which statement about grounding systems is true? ✔️Ans - The resistance should be 25 ohms or less.Which of the following statements regarding bonding are true? Select all that apply. ✔️Ans - Bonding reduces the threat of sideflash by providing a low impedance path to ground.Bonding is a way of connecting LPS conductors to grounded metal objects.When should a grounded metal object be considered for bonding? ✔️Ans - When it's within 6 feet of a conductor Which bonding method is the most permanent and secure? ✔️Ans - Exothermic weld Which factors are used to calculate bonding distance?Select all that apply.✔️Ans - Height of proposed bond Flashover medium Number of down conductors While conducting the inspection, John's team noticed a new metal light pole installed 3 feet from the down conductor at the corner of this building. They logged a discrepancy. Why? ✔️Ans - Because grounded metal objects within 6 feet of LPS conductors should be bonded to it Which types of information does an LPS record provide? Select all that apply.✔️Ans - Test locations Test item descriptions or listing
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