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The AZ-EC exam has 110 questions and runs 4 hours.
These 10 free AZ-EC questions are organized by exam domain, so you can see how each part of the Arizona C-11 (CR-11) Electrical (Commercial) Trade Exam blueprint is tested. Reveal the answer and explanation under each question.
Before a 120 V display circuit is added to an older store, a qualified electrician records 240 V between every pair of phase conductors. Phase-to-neutral readings are A: 120 V, B: 208 V, and C: 120 V; all remain steady as existing loads are switched. Which interpretation should guide the connection?
Correct answer: C - A high-leg delta service permits the display on A-to-neutral or C-to-neutral.
Six thermostatically controlled appliances on a restaurant kitchen feeder are rated 22, 18, 6, 5, 4, and 3 kW. They all qualify for 2017 NEC 220.56, and the table's demand factor for six appliances is 65%. What minimum demand load must this group contribute to the feeder calculation?
Correct answer: A - 40.0 kW
A permanent 208Y/120 V generator supplies a building through a three-pole transfer switch. All three phase conductors transfer, but the neutral remains connected to the service neutral. The service has the required neutral-to-ground bond, and an equipment grounding conductor connects the generator frame to the service equipment. Which connection would create an objectionable parallel path for normal neutral current?
Correct answer: A - Bonding the generator neutral terminal to the generator frame.
No water is visible inside a newly installed underground PVC raceway for parking-lot lighting. The delivered copper conductors are marked THHN only, with no additional insulation-type marking. The raceway installation otherwise complies with the 2017 NEC. Which instruction produces a compliant conductor installation?
Correct answer: C - Keep the PVC raceway and use conductors marked THWN-2.
Which control-station marking is suitable for the following installation? The approved area-classification drawing identifies a Class I, Division 1, Group D solvent-handling location. The maximum permitted equipment surface temperature is 170°C. All four stations have suitable ambient ratings and meet the other installation requirements.
Correct answer: D - Class I, Division 1, Groups C and D; T3C
During commissioning of an operating-room isolated power system, the line isolation monitor displays 6.4 mA of total hazard current and gives its audible and visual alarm. The branch circuits remain energized. Which statement correctly interprets this behavior under the 2017 NEC?
Correct answer: D - The monitor warns of excessive potential hazard current; it does not automatically disconnect the circuits.
An owner requests a three-slot replacement for a worn two-slot receptacle on an otherwise sound, existing two-wire office circuit. The circuit has neither GFCI protection nor an equipment-grounding path, and the work adds no outlets or wiring. Which response correctly applies the 2017 NEC replacement rule?
Correct answer: D - Install a GFCI receptacle and mark it "No Equipment Ground."
A conventional fire-alarm circuit uses normally open initiating contacts and a 4.7-kilohm end-of-line resistor. The manufacturer requires the resistor at the last field device: 4.7 kilohms indicates normal, an open indicates trouble, and a closed contact indicates alarm. Acceptance-test results are: Panel input functional checks: passed. Both field conductors disconnected at the panel: zone remains normal after the full fault-reporting delay. What installation error accounts for the false-normal indication?
Correct answer: B - The end-of-line resistor is connected across the panel input terminals.
All identified energy sources to a 480 V motor-control cabinet have been isolated and locked out. A qualified electrician proves the contact tester on a known energized source, obtains zero on every required cabinet voltage check, then finds that the tester fails its final proving check on that still-energized source. What must happen before conductor contact is permitted?
Correct answer: B - Repeat the checks with a functioning, properly rated tester, proving it before and after use.
An inverter permits a maximum DC input of 550 V. Each proposed crystalline-silicon module is rated Voc = 43.0 V and Vmp = 35.0 V at a cell temperature of 25°C. The manufacturer's Voc temperature coefficient is -0.30% per °C, and the lowest design module temperature is -10°C. Considering only the maximum-voltage constraint, what is the largest permissible number of modules in one series string?
Correct answer: C - 11 modules
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