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ES3 NM Questions and Correct Answers
Updated 2025 Graded A
110 block - ANSTo terminate on-premises wiring in structured cabling. IDC or Insulation displacement contact connector is used to terminate the twisted pair. The 110 allows for a much higher density of terminations, less crosstalk and higher bandwidth data. 125% / 100% - ANSConductors should be no less than 125% of the continuous loads plus 100% of the non-continuous loads. 5 / 100 - ANSAn area with 5 or less thunderstorm days a year and earth resistivity of 100 ohmmeters is not lightning exposed. 66 block - ANSA punchdown block that terminates 22 to 26 AWG solid copper wire. The 25 pair standard non split 66 block contains 50 rows. A metal underground water pipe - ANSIs permitted if in direct contact with the earth for 10 feet or more. NEC 250 Addressable Fire Alarm System - ANSMore versatile and more features than conventional systems. Each initiating device is assigned a unique identification or address. The panels also allow a device to have a descriptive name. Like conventional systems they are either in alarm or normal condition.
Addressable System wiring - ANSUses a single pair of wiring that connects to all devices and control modules. Allows for T-Tapping instead of home runs back to the FACP. Alternating Current (AC) - ANSTravels continuously with reversing directions. It also continuously changes between positive and negative. Ampacity - ANSThe current carry capacity of conductors or equipment expressed in Amperes. Amplitude - ANSThe maximum voltage that can be reached by a signal measured in volts. Balun - ANSA means of matching an unbalanced antenna or transmission line to a balanced transmission line or antenna (Usually have a transformer in them) Bus Topology - ANSAll nodes are connected to a single shared communication line Cable clearance above a sidewalk - ANSat least 9.5 feet Cables should be supported by - ANSThe building structure Class 1 circuits - ANSsupplied from a source that is rated 30 Volts or below
Coluombs Law - ANSQuantifies the amount of force between two stationary, electrically charged particles. The electric force between charged bodies at rest is conventionally called electrostatic force or Coulomb force. Communications cables location - ANSshould be below electric light or power conductors Communications wires should be what distance from lightning conductors?
- ANSSix feet or more Concrete Encased Electrode - ANSConsist of either continuous 20' of bare or galvanized zinc or steel bars/rods not less than 1/2" in diameter or bare copper conductor not smaller than 4 AWG Conductors for general wiring - ANSThe equipment grounding conductor NEC 310 shall be 10 AWG or larger if in a listed cable assembly. Conventional Fire System zone configuration requirements? - ANSCommon devices should be grouped together in a zone and Trouble condition on a zone should indicate some sort of wiring or device problem. Conventional Fire Systems - ANSTwo types of zones. Initiating and Notification zones. The number of initiating zones defines how large the system can be. Most conventional zones use a two-wire scheme and end of line resistor for supervision or IDC.
Conventional System wiring - ANSEach zone must return to the panel and an end of line resistor must be installed to maintain supervision. All wiring must home run back to the FACP. Conventional vs Addressable in Alarm Condition - ANSConventional provides zone in alarm while Addressable provides device in alarm and location. Conventional Vs. Addressable in Troubleshooting - ANSConventional provides trouble zone while Addressable provides detailed information on trouble source. Crossover - ANSDivide an output into separate circuits each covering a specific band or frequency range. Current or Current Flow - ANSThe movement of electrons through a circuit that is caused by the electromotive force or voltage applied to the circuit. Dry Contact Devices - ANSNormally open switch which close on activation and creates and alarm. Pull stations, heat detectors, four wire smoke detectors, sprinkler supervisory switches. Electrical circuit - ANSIs comprised of an energy source, energy transfer medium and a load. Electrical Signal - ANSRefers to the voltage which can convey information.
Ground Loop - ANSCauses a current to flow in the low resistance of the shield resulting in electromagnetic waves that are picked up as noise through the wire. Grounding - ANSassures transmission of electrical signals without interference from electromagnetic radiation from other transmission lines and equipment. This interference, called crosstalk, can happen from adjacent lines, motors, PCs, lights and other devices. Grounding electrode - ANSConnection to the electrode should be less than 1 ft below the surface of the solid and the electrode should extend at least 10 ft below ground. Hertz (Hz) - ANSThe rate of changing direction in AC is measured in Hertz. IDC - ANSInitiating Device Circuit. The IDC connects an auto or manual initiating device to a zone or a monitoring module. Inductance (L) - ANSUnit is the henry. It is the property of a circuit that causes an opposition to any change of current within the circuit. As electrons flow, a magnetic field is produced. The magnetic force induces a change in voltage. Insulated grounded conductor - ANSWhite, gray or three white stripes and 6 AWG
inverse square law - ANSEach doubling of distance from the sound source results in a fourfold reduction of sound power (equal to 6db). If one moves 4' to 8' from a sound source, the level is reduced by 6 db. Double the distance to 16' and the level is reduced another 6db to 12 db. Live wire - ANSHot wires are live and carry the electrical power. The live wire is an ungrounded connector. The neutral is a grounded connector. Load - ANSreceives the transferred energy such as resistors, lights, speakers, motors, etc. Manual Alarm Station types - ANSSingle, Dual, Break Glass and Key. At least one manual pull station is required when either a fire alarm or monitored sprinkler system is installed. Max number of Waterflow switches connected to a zone? - ANS Maximum number of Supervisory Switches connected to a zone? - ANS Metal In-Ground Support Structure - ANSOne or more in direct contact with the earth vertically for 10 feet or more with or without concrete encasement NACs - ANSNotification Appliance circuits. In Class B, each NAC has its own EOLR. In Class A, the EOLR is not required and a redundant path is included.
Pull station requirements - ANSMount 3.5' to 4' AFF. Colored Red and marked FIRE. Located within 5 feet of each egress on each floor. No more than 200 feet travel distance between pull stations. Raceways or bushings that enter a building should be - ANSsloped upward from the outside with drip loops formed RHH wires - ANSRubber insulated with high heat resistance and good in dry locations. RHW - ANSRubber insulated and suitable for wet locations. Ring Topology - ANSTopology where the computers are connected on a loop or ring. Roof clearance for communications cables - ANSshould be at minimum 8' vertical clearance Signaling Line Circuit (SLC) - ANSUsed in addressable Fire Alarm Systems to communicate with detectors and modules. SLCs can perform remote relay functions, dry contact monitoring, remote power control, releasing service and conventional zone monitoring. SLC advantages? - ANS2 way communication between a device and the panel via an SLC circuit. The panel and device poll each other every 4 - 5 seconds.
Sleeping area DB - ANSMaximum sound level of at least 60 seconds of at least 75 dbA, whichever is greater, measured at the pillow level. Smoke detector distance - ANSThe distance between smoke detectors shall not exceed a nominal spacing of 30 feet. Smoke detector types - ANSIonization and Photoelectric. Ionization is less reliable and produces more false alarms. Less reliable at altitudes above 3000 ft. Photoelectric works by light scattering or light obscuration which is used for spaces greater than 900 feet. Smoke detectors and HVAC diffusers - ANSMust not be located within 3' of a diffuser Star Topology - ANSA topology with one central node that has each computer or network device attached to the central node. All data first goes into the central node and then is sent out to its destination. Strobe requirements - ANS20' wide corridor. 15 candela (cd) minimum, 15' of the end of the corridor, no more than 100' apart, synchronized to flash at the same time. Switches - ANSSingle pole, single throw has one line up on left and one dot on right; single pole, double throw has one line up on left and two dots on right; double pole, single throw has two lines up on left and two dots on right; double pole, double throw has two lines up on left and four dots on right;
Visible notification - ANSRequired when ambient sound level is greater than 105 db. Wall mounted audible device and strobe mounting - ANSMount between 80 and 96" AFF and at least 6" below the ceiling. Watts - ANSMeasure of power Wiring System - ANSIs a form of electrical circuit. Workspace headroom for work under 600V - ANSMinimum of 2 meters or 6.5 feet
