Cable Pulling

Understanding the M-Wall, E-Wall and RBlock in DB6X

Voltage Classification

Electrical power systems can be divided into four main categories:

  • Generation
  • Transmission
  • Distribution
  • Consumption

Because efficiency considerations each of these categories are operated in different voltage levels:

  • Low Voltage (LV): Up to 1000V, consumption.
  • Medium Voltage (MV): between 1000 V and 35000 V (35 kV), distribution. (11kV in DB6X)
  • High Voltage (HV): Voltage between 35 kV and 230 kV, transmission.
  • Extra High Voltage (EHV): Voltage from 230 kV and above, transmission.

 

  1. The power comes from the national grid to a local substation.
  2. The voltage from the national grid is too high so it needs to be reduced in the substation. This happens by going through the transformer.
  3. The transformer receives power from the Site Substation and Generators. Backup supply is always required.
  4. The voltage is now considered Low and that is where you get LV cable from.
  5. This LV cable goes to the Local UPS room where the Switch boards are located typically inside the building.
  6. Then the power goes from here to the PDU (Power Distribution Units) inside the data halls then this feed the servers.



Equipment Power Distribution

 Transformer

  •  Ring Main Unit (RMU)
    • The function of the ring main unit (RMU) is to link the loop network. This helps to increase the stability of the power supply.
  •  Load Bank Panel (Essential Panel)
    • Load banks are used to commission, maintain, and verify electrical power sources such as uninterruptible power supplies (UPS).
    • The load bank applies an electrical load to the power source and dissipates the resulting electrical energy through resistive elements such as heat.
    • The resistive elements are cooled with motorized fans within the load bank construction.
    • Load banks are the best way to replicate, prove and verify the real-life demands on critical power systems.

Customer Feeder

  • Batteries
    • The batteries in a UPS system provide emergency power when the mains supply fails.
  • UPS
    • A UPS, or uninterruptible power supply, provides backup power when the main source of power fails or drops to a very low level. UPSs are a necessary component of protection for server room power. Much like a UPS, backup generators are also vital for the success of server rooms.
  •  Static Transfer Switchboard
    • Static Transfer Systems (STS) are intelligent switches providing increased supply availability, automatically transferring loads to alternative power sources when the primary power source fails or is not available.
    • This serves as a back up to eWall it is assigned to. In case of a failure of power distribution from the UPS room to the load, the load is then served from the STS room which is backed up by the R-block busbar loop.
  • Switchboard
    • An electrical device that distributes electricity from one electrical source to another electrical source.
    • It is a major component used in the power distribution process.
    • It is made up of several electric panels.
    • Each electric panel contains switches that redirect electricity.
    • The main purpose of the board is to control the flow of power. It divides the main current supplied to it into several smaller chunks and distributes it to the devices. 


Checking Cable Pulling and Terminations

If you want to understand how the cable pulling and terminations have been tracked in DB6X, follow the example below. In this example, we will be showing how are we tracking the cable pulling in Zone C.

Step 1:

Open the Room Layout drawing to get yourself familiarized by the equipment tags. This information can be found in ASITE.

DB061-RED-DC-XX-DR-E-MEPH-5006-DB6x - Electrical Services R-Block Detail-P03-Phase 1

UPS ROOM

Equipment List

Transformer Room / Battery Room

Equipment List

Step 2:

Check the power cable schedule. This information can be found in ASITE.

DB061-RED-ZZ-ZZ-SH-E-POWR-6001-DB6x Cable Schedule-P06-Phase 1

P.018028 - DB6x - DB6 Cable Schedule

Look for the equipment in the schedule. We will run in detail through the example below:

  • UPS Room -> 1-MSB-R2: Input Switchboard or Main Switchboard

 

By looking at the schedule, we can determine the below power cables are being distributed from the Output/Main Switchboard:

  • 1 x 1 x 4c = 9 lines with this reference = 9 cables
  • 2 x 1 x 4c = 1 line with this reference = 2x1 = 2 cables
  • 2 x 4 x 4c = 1 lines with this reference = 2x4 = 8 cables

TOTAL: 19 cables

Step 3:

Cross reference the information taken from the schedule with the LV power schematic for the area.

Note:

§ CBL-R2-IP-008 represents 8 cables as checked above.

§ The Spare cables are not taken into consideration as these are not represented in the cable schedule.

DB061-RED-ZZ-ZZ-SC-E-POWR-7006-DB6x and 7x - RBlock LV Schematic-P08-Phase 1

Step 4:

Check Model Viewer for Cable Pulling

As you can see in the image below, we have tracked 10boxes.

Remember, these 10 boxes represent 10 cable references.

  • 9 boxes are representing 9 cables.
  • 1 box is representing 2 cables.
  • 1 box is representing 8 cables.

The photos below are showing why these 9 boxes have been marked as completed in the cable pulling model.

Pulled cable total count: 15 cables. These are 15 cables out of 19 cables. We have considered the 1 box that represents 8 cables is not yet finished. If on site, the cables are tagged correctly, you will be able to track these more accurately but sometimes you will need to make assumptions. 

Step 5:

Check Model Viewer for Cable Terminations.

Same logic applied for cable pulling is also applied on cable terminations check.

  • 9 boxes are representing 9 cables.
  • 1 box is representing 2 cables.
  • 1 box is representing 8 cables.

As seen in the photos above, there are a total of 8 cables terminated. These 8 cables have been marked as completed in the cable pulling model.

Note:

  • You might be wondering why the Load Bank Panel 1-LBSB-R2 is shown in red.
  • In DB6X when there was just 1 cable reference for the piece of equipment as per the schedule, in most of the cases, we have linked the equipment rather than creating 1 additional small box. This might vary in future projects; we are just showing the way it has been done in DB6X.

By now you should be familiar on how to check the power to the equipment by looking at the cable pulling schedule, schematics and marking these on the cable pulling and cable terminations models. Let’s do an example on how the power is distributed now from these panels to different equipment. 

Example on Distribution

If we take the example of the panels below:

  • 1-DB-R2-01: General Essential Mechanical Services L+SP
  • 1-DB-R2-05: BMS/ENMDS Comms Panel

 

Step 1:

Looking at the Cable Schedule we can identify the power distributed to these 2 panels. This exercise is exactly the same as the one we have done in section 1.

DB061-RED-ZZ-ZZ-SH-E-POWR-6001-DB6x Cable Schedule-P06-Phase 1

P.018028 - DB6x - DB6 Cable Schedule

1-DB-R2-01 is being served by the RBlock Main Switchboard 1-MSB-R2

1-DB-R2-05 is being served by the Rblock Output Switchboard 1-UDPR-R2.

Step 2:

You can cross reference the information taken from the Cable Schedule with the Schedule of DBs below. This schedule is just telling us how many distribution boards we will find in the project and which equipment are these supplied from:

P.018028 - Equinix DB6x

Schedule of DBs

DB061-RED-ZZ-ZZ-SH-E-POWR-6003-Schedule of DBs-P04-Phase 1

In this case, we are cross referencing the information we checked in Step 1 is the same information we have in this schedule. There should not be any deviation, but it is a good practice to cross reference and to always check.

Step 3:

By looking at the Distribution Board schedule below, you can see how the cables are distributed from this boards to the lights, fans etc.

P.018028 - DB6x Equinix - Stage 4

DB6x Distribution Board Schedule

DB061-RED-ZZ-ZZ-SH-E-POWR-6004-DB6x Distribution Board Schedule-P06-Phase 1






Lessons Learnt

Cool Array - Tap off boxes

Cool Arrays - Progress Capture.

Examples of cable pulling and terminations on site

1.   CRAC units:

A CRAC unit is a mechanical element, so it just receives power from boards.

The 1-CRAC-R2-19 in the UPS room is being powered by:

  • Mwall: Output Swithcboard 2, 1-UMDSB-M3-2.
  • RWall: Output Switchboard, 1-UDPR-R2.

2. Transformer room: 

3.   General LV 

4.   Extract Fan

5.   Dampers

6.   Fire Alarm

7.   Sound Beacon Fire Alarm

8.   Three Phase Power Supply

9.   Fire Alarm Interface

10.   Manual Call Point Fire Alarm

11.   Disabled Toilet Alarm System

12.   Fire Alarm

13.   Lights

14.   Exit Signal

15.   Solar Panels

16.   Vesda Panels

17.   CCTVs

18.   Socket and Switches 











Complete and Continue