# Power And Cooling CBT

19 Questions | Total Attempts: 95  Settings  This Power and Cooling CBT is used to test the knowledge of NAMs on site specs and offerings.

• 1.
A "One Line Diagram" or a "Single Line Diagram" is:
• A.

A drawing showing the major components of a system and how they are linked together.

• B.

Usually considered “confidential” and rarely shared with Customers.

• C.

Used to show the topology of major facility infrastructure.

• D.

All of the above

• 2.
The two types of power circuits are:
• A.

Amperage Current and Digital Current

• B.

Alternating Current and Digital Current

• C.

Alternating Current and Direct Current

• 3.
The term, “UPS” stands for:
• A.

Universal Power Supply

• B.

United Parcel Service

• C.

Uninterruptible Power Supply

• D.

Uniform Power Surge

• 4.
Place the following electrical components in order, from highest upstream (utility company) to lowest downstream (IT equipment on the floor).
• A.

PDU, UPS, Generator, Substation

• B.

Substation, Generator, UPS, PDU

• C.

Generator, Substation, UPS, PDU

• D.

UPS, PDU, Generator, Substation

• 5.
Power (Watts) is the product of voltage (Volts) and current (Amps), or  P = V x I.   If we have one, 120 VAC single phase circuit at 20 Amps, the corresponding power is:
• A.

240 W

• B.

2.4 KW

• C.

60 W

• 6.
Three Phase AC circuits are comprised of three independent electrical potentials, offset by 120 degrees.  Power (Watts) is the product of voltage (Volts) and current (Amps), or  P = V x I.   If we have a single 208 VAC three phase circuit at 30 Amps, the corresponding power is:
• A.

6.2 KW

• B.

749 KW

• C.

10.8 KW

• 7.
An Uninterruptible Power Supply does what?
• A.

Provides power backup during a power outage

• B.

Conditions power, changing power from “dirty” to “clean”

• C.

All of the above

• D.

None of the above

• 8.
Utility power is delivered to the data center as DC power.  It is then converted to AC power by the Generator and UPS.
• A.

True

• B.

False

• 9.
Which of the following is a derived unit of heat energy for heating or cooling capacity?
• A.

BTU

• B.

Watt

• C.

Volt

• D.

Amp

• 10.
What is the difference between “Breaker” and “Load” power?
• A.

Breaker power is the rating of the circuit breaker and Load power is the power at which the circuit breaker will trip.

• B.

Breaker power is the amount of power that will trip the circuit breaker and load power is the size of the power feed from the utility company.

• C.

Breaker power is the amount of power delivered to the rack/cabinet and load power is the amount of power drawn that will trip the circuit breaker.

• D.

Breaker power is the amount of power available to be delivered to the rack/cabinet and Load power is the amount of power used by the equipment in the rack/cabinet.

• 11.
The capacity of a data center is expressed in terms of:
• A.

Watts per Square Foot

• B.

Watts per Cabinet

• C.

Both “a” and “b”

• 12.
True or False:  Three Phase DC power is more efficient than Three Phase AC power?
• A.

True

• B.

False

• 13.
The reason that we have limits on the amount of power we will support in any one rack or cabinet is:
• A.

The size and weight of power cables to any one cabinet has to be controlled because of the limitations of the overhead ladder racks supporting those cables.

• B.

We have allocated a budget for the amount of power we will deliver to any one rack on the floor.

• C.

A “hot” cabinet will negatively impact adjacent Customer cabinets because of the site’s capacity to cool the cabinets.

• D.

The floor space is pre-wired for a certain maximum power, and provisioning power beyond those levels requires additional NRC.

• 14.
The Power Rating increments that we use for our basic product set are:
• A.

2KW, 4KW, and 7.2KW

• B.

4KW, 6KW, and 7.2KW

• C.

2.4KW, 4KW, and 6KW

• D.

2.4KW, 4.8KW, and 7.2KW

• 15.
DC power is a constant voltage and current level that is not time dependent.  AC power, on the other hand, follows a sinusoidal wave form that changes over time at a rate of 60 cycles per second (60Hz) (in North America).  The following is a graph of an AC voltage waveform: If this is the voltage waveform measured at the output of the power circuit, what is the AC power implied by this graph?
• A.

170 VAC

• B.

340 VAC

• C.

120 VAC

• D.

0 VAC

• 16.
IT equipment installed in a colo facility is usually dual corded, meaning it contains two power supplies.  This is so that the equipment can operate even if a power supply fails, which is a fairly common occurrence.  If a server has two, 500 Watt power supplies, what is the maximum power that it will draw?
• A.

500 Watts

• B.

1,000 Watts

• C.

250 Watts

• 17.
The term, “Minimum Cabinet Rating” (MCR), is a new term used at Switch and Data that identifies the lowest rating level of cabinet that we will sell to a Customer in a given site.  It is computed by taking the total rated power across all the cabinets owned by that Customer in that site, and dividing by the number of cabinets they own in that site, and rounding up to the next highest cabinet rating.  For example, if Acme Co. has four 2.4kw cabinents, three 4kw cabinets, and five 6kw cabinets, the MCR = [ (4 * 2.4) + (3 * 4) + (5 * 6)] / (4 + 3 + 5) = [9.6 + 12 + 30]/12= 51.6/12= 4.3, rounded to 6… or MCR=6. Use the following example to compute the MCR: The CSE examines the Customer’s equipment inventory, and concludes that there will be five cabinets with actual power draw as follows: Cabinet 1:  4.8kw Cabinet 2:  1.8kw Cabinet 3:  3.5kw Cabinet 4:  5.8kw Cabinet 5:  3.8kw   What is the MCR for this Customer?
• A.

1.8kw

• B.

2.4 kw

• C.

4kw

• D.

6kw

• 18.
• A.

Load amps is always greater than breaker amps

• B.

Load must be no more than 80% of breaker amps

• C.

Both load and breaker current are important in designing a Customer solution

• D.

Both B and C

• 19.
What is the primary purpose of a raised floor in the data center?
• A.

It is a cold air plenum for cooling of Customer equipment

• B.

Enhance survivability of Customer equipment in case of a flood in the data center

• C.

It is where cabling is located so that the raised floor is not cluttered with wiring

• D.

The scaffolding of the raised floor distributes the weight of Customer equipment allowing the data center floor to bear more load

Related Topics Back to top