10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The CDCS exam has 73 questions and runs 3 hours 15 minutes.
These 10 free CDCS questions are organized by exam domain, so you can see how each part of the Certificate for Documentary Credit Specialists blueprint is tested. Reveal the answer and explanation under each question.
A vendor proposes three 400 kW UPS modules to support a planned critical load of 780 kW, describing the arrangement as N+1 redundant. The single-line diagram shows all three modules feeding one output switchboard, from which a single distribution path serves the data hall. What is the correct assessment of this design?
Correct answer: D - Capacity redundancy only; the single distribution path remains a single point of failure
A facility is built with two fully independent 2N power trains, each with its own UPS, batteries and distribution. Both trains are installed in the same plant room, within a single fire compartment. With respect to fault tolerance, what is the PRIMARY deficiency of this arrangement?
Correct answer: C - A single event in the shared compartment can disable both trains at once
A cabinet dissipates 6 kW of heat and the installed equipment has a temperature rise (ΔT) of 10 K across it. Approximately what volume of air must be delivered to the cabinet intake to remove this heat?
Correct answer: C - Approximately 1,790 m³/h
A supplier offers a UPS rated 300 kVA / 240 kW to support a planned IT load of 260 kW, stating that the unit has ample headroom because the load is comfortably below 300 kVA. What is the correct assessment of this offer?
Correct answer: A - The unit is undersized; its 240 kW real power rating is below the 260 kW load
A data hall shows a return-to-supply temperature difference at the CRAH units of only 4 K, against a design equipment ΔT of 12 K. Installed cooling capacity comfortably exceeds the IT load, and no cabinet is reporting an elevated inlet temperature. Which condition is MOST likely present?
Correct answer: B - Conditioned air is bypassing the IT equipment and returning directly to the units
An engineer is calculating the agent quantity for a clean agent suppression system protecting a data hall. The hall has a 600 mm raised floor void and a suspended ceiling void, both of which fall inside the protected zone. Which volume must be used in the calculation?
Correct answer: A - The room volume plus the raised floor void and the suspended ceiling void
A three-phase distribution board supplies a balanced load at 400 V phase-to-phase. The measured line current is 100 A and the power factor is 0.9. What is the approximate real power being delivered?
Correct answer: B - 62.4 kW
An organisation is comparing Top-of-Rack (ToR) and End-of-Row (EoR) switching architectures for a new data hall. What is the PRINCIPAL disadvantage of the ToR approach?
Correct answer: D - It significantly increases the number of switches that must be managed and maintained
A facility maintains 24 °C (75.2 °F) measured at the return air inlet of every CRAH unit and claims compliance with the ASHRAE recommended thermal envelope. Which objection to this claim is valid?
Correct answer: A - The envelope applies at the IT equipment air inlet, not at the unit return
A 25-year-old data centre is scheduled to have its raised access floor tiles lifted and replaced while the facility remains live. Which specific contamination risk must be assessed and controlled before the work begins?
Correct answer: D - Release of zinc whiskers from electroplated components in the floor understructure
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