CDCP Exam Questions & Answers

A steam canister humidifier is a type of humidifier that uses electricity to heat water in a canister containing electrodes. The water conductivity and the water level determine the amount of current and steam production. The steam canister humidifier is also known as an electrode boiler humidifier or an electrode steam humidifier123.

A UPS (uninterruptible power supply) that is categorized as VFD class is not a fit for your mission-critical data centre, because it does not provide adequate protection against voltage and frequency variations. VFD stands for Voltage and Frequency Dependent, which means that the output voltage and frequency of the UPS depend on the input voltage and frequency. VFD UPSs are also known as offline, standby, or line-interactive UPSs. They typically switch to battery power only when the input power fails or goes beyond a certain threshold. However, this switching may cause a brief interruption or a transient in the output power, which can affect the performance and reliability of the ICT equipment. Moreover, VFD UPSs do not filter or regulate the input power, which means that they pass on any voltage or frequency fluctuations, harmonics, or noise to the output power. These power quality issues can also damage or degrade the ICT equipment and the data.

For your mission-critical data centre, you need a UPS that is categorized as VFI class, which stands for Voltage and Frequency Independent. VFI UPSs are also known as online, continuous, or double-conversion UPSs. They provide a constant and clean output power that is independent of the input power. VFI UPSs convert the input AC power to DC power, and then convert it back to AC power with the desired voltage and frequency. This double conversion process isolates the output power from the input power, and eliminates any power quality issues. VFI UPSs also have zero switching time, which means that they do not cause any interruption or transient in the output power when switching to battery power. VFI UPSs are designed to protect the ICT equipment and the data from any adverse effects of voltage and frequency variations, and to ensure the highest level of availability and reliability.

1: CDCP Preparation Guide, page 17, section 2.3.1 2: Understanding UPS Classification: Fuji Electric's Technical Guide3, page 1, section 1 4: Uninterruptible Power Supplies Key Product Criteria5, page 1, section 1 6: UPS Function: Reduced Input Voltage for VFDs - KEB7, page 1, section 1

Infrared humidifiers are a type of humidifier that use quartz lamps to heat water in an open pool and evaporate it into the air. They are energy-intensive and require frequent maintenance and cleaning. They are not recommended for data centers, as they can introduce contaminants and bacteria into the air, and increase the risk of fire and electrical hazards.

According to the EPI Data Centre Operations Standard (DCOS), exit/emergency signs should be located at every escape door and pathways leading to doors (arrows) to ensure a safe and quick evacuation in case of an emergency1. This is also consistent with the best practices for data centre emergency preparedness and response, which recommend having a clear and visible signage system for emergency exits23.

According to the EPI Data Centre Professional (CDCP) Reference Materials, the recommended number of monitoring points for temperature measurement in a data centre is 3 per rack: one at the top, one at the middle, and one at the bottom1. This is to ensure that the temperature distribution within the rack is uniform and within the acceptable range for the equipment. The temperature sensors should be placed at the front of the rack, where the air enters the equipment, and not at the back, where the hot air exits1.