Specific Electrical Requirements for Industrial Buildings- Part Two



In the previous Topic “Specific Electrical Requirements for Industrial Buildings- Part One”, I clarified that any designer wants to optimize his design for industrial buildings by completely satisfying the users’ individual needs for these buildings which are: 
  1. Workshop and office flexibility.
  2. Production facility availability, continuity of service.
  3. Time, investment and operating cost control.
And I show that these needs must be satisfied in the following three levels of electrical design for power distribution architecture which are:
  1. General distribution.
  2. Sub-distribution.
  3. Final distribution.
Actually, Each industrial site has its own particular needs and requires a specific type of power distribution architecture based on the following principles:
  1. Cost optimization, which is closely, linked to the location of the MV/LV substations, 
  2. Availability, which is primarily governed by the higher levels of the architecture, 
  3. Flexibility, which is based mainly on the sub-distribution and final distribution design 
These principles can be applied in different types of power distribution architecture, especially in the common three types which are:
  1. "Radial branched" power distribution architecture,
  2. "Dual-transformer shared" power supply distribution architecture,
  3. "Multiple-transformer shared" power distribution architecture.
In the previous Topic as referred above, I explain the first type of power distribution architecture; "Radial branched" and today I will continue explaining the other two types as follows:

"Dual-transformer shared" power supply distribution architecture.


Dual-transformer shared
This power supply distribution architecture meets the needs for increased flexibility and availability for all industrial buildings.

The electrical design levels in this power distribution architecture will be as follows:

1- General distribution Level
It will include two MV/LV substations; both substations will supply the main switchboard (via cables or high power busbar trunking ) with low voltage at the same time, and the main switchboard will supply a high-current busbar trunking.

That is why this power supply distribution architecture is known as a "dual-transformer shared".

2- Sub-distribution Level
In this level, Loads are supplied as follows:
  • Large structural loads, such as painting equipment, are supplied directly via cables from the main switchboard on the nearest MV/LV substation. The rating of the high-current busbar trunking consequently relieved of such loads is reduced. 
  • High-power machine cubicles will be fed directly via medium or low power busbar trunking. 
  • The local sub-distribution board in the office zone is supplied directly via cables from main switchboard. 
  • The other power loads are supplied from the high-power busbar trunking.

3- Final distribution Level
In this level, each final load will be supplied as follows:
  • The mobile devices connected via their industrial outlets are supplied from multi-functional weatherproof enclosures. 
  • The lighting throughout the workshops is distributed via lighting busbar trunking fed from the local sub-distribution board.
  • Mobile workstations are supplied via industrial poles. 

Evaluation of "Dual-transformer shared" power distribution architecture:
  • This architecture type is optimized more than the “Radial-branched” architecture, as it is designed to provide the process with a distributed power at general and sub-distribution level, making it easier to connect the loads throughout the industrial buildings, irrespective of their location. 
  • The design of both the power sub-distribution and the general power distribution can therefore be more independent of the process design. 
  • This architecture satisfies the high level of availability required by sensitive loads (servers, programmable controllers, etc.) due to its protected supply which ensures the operation of critical connected equipment in the event of the failure of one of the two MV/LV substations because each load will be supplied simultaneously by both transformers. 
  • This architecture (Both the general and sub-distribution) uses mainly factory built components (busbars and sub-distribution boards components) for more standard flexibility, availability, time and cost control requirements which result in the following: 
  1. Shorter installation time. 
  2. Easy deal with design (specifications, inaccuracies, etc.), installation (worksite, hazards, etc.) and operating (modification, workshop relocation, etc.). 
  3. The reliability of the plant is guaranteed 

This power distribution architecture has the following evaluation:



Flexibility
***
Availability
***
Time and Cost Control
***


"Multiple-transformer shared" power distribution architecture


Multiple-transformer shared
This power supply distribution architecture meets the very high flexibility and availability for all industrial buildings

The electrical design levels in this power distribution architecture will be as follows:

1- General distribution Level
It will include many MV/LV substations connected in a low voltage loop by high-power busbar trunking which can connect about four MV/LV substations.

That is why it is known as a "multiple-transformer shared" power distribution architecture.

2- Sub-distribution Level
In this level, Loads are supplied as follows:
  • Large structural loads, such as painting equipment are supplied directly via cables from the main switchboard on the nearest substation: the rating of the high-current busbar trunking consequently relieved of such loads is reduced. 
  • The high-power machine cubicles, in addition to the roof mounted heat pumps, will be supplied via the medium-power busbar trunking. 
  • The local sub-distribution board in the office zone is supplied directly Via cables from main switchboard. 
  • The other loads are supplied directly from the low-voltage loop.

3- Final distribution Level
In this level, each final load will be supplied as follows:
  • The mobile devices connected via their industrial outlets are supplied from multi-functional weatherproof enclosures. 
  • The lighting throughout the building is distributed via lighting busbar trunking. 
  • Mobile workstations are supplied via industrial poles. 

Evaluation of Multiple-transformer shared" power distribution architecture
  • This architecture is best optimized type, as it is designed to provide the process with a distributed supply at general and sub-distribution Levels and making it easier to connect the loads in all industrial buildings, whatever their location. 
  • This architecture satisfies the high level of availability required by sensitive loads (servers, programmable controllers, etc.) due to its protected supply because it ensures that the critical connected equipment continues to operate in the event of MV/LV substation failure for example; if one substation fails, 3/4 of the total power remains available. 
  • This type of architecture is particularly justified economically when industrial buildings use reversible heating/air conditioning components (for ex. Roof mounted heat pumps). This equipment in fact requires considerable additional, evenly-distributed power of 100VA/M2. 
  • This architecture (Both the general and sub-distribution) uses mainly factory built components (busbars and distribution boards components) for more standard flexibility, availability, time and cost control requirements which result in the following: 
  1. Shorter installation time. 
  2. Easy deal with design (specifications, inaccuracies, etc.), installation (worksite, hazards, etc.) and operating (modification, workshop relocation, etc.).
  3. The reliability of the plant is guaranteed.

This power distribution architecture has the following evaluation:



Flexibility
****
Availability
****
Time and Cost Control
***


Comparison of the three common power distribution architectures with regard of satisfying the user needs will be as follows:


"Radial branched"
"Dual-transformer shared"
"Multiple-transformer shared"
Flexibility
**
***
****
Availability
**
***
****
Time and Cost Control
**
***
***

Actually, each industrial site has its own particular needs and requires a specific type of power distribution architecture, the selection between these common types of power distribution architecture is usually based on the following points:
  1. Type of building use.
  2. Level of building installations, equipment and furnishing.
  3. Building’s Cost budget.
  4. User needs from the building.
  5. Regulations of utility companies and local authorities.
You can use the preliminary design checklist for listing the above information and then you will be able to select the right type of power distribution architecture for each case.
For me, I use the advanced preliminary design checklist to do this which has the following advantages:

1- The best professional form for Establishment preliminary design phase
It include all the factors that can influence an electrical design for any project such as Site topology, Service reliability, Load distribution, Environmental impact and etc.

2- Very easy to use
It guides you step by step to design the power distribution architecture for any project.
Besides, it is an excel form; you need only to put marks (√) beside your selection from the multiple choices for each design step.

3- Increase you designs’ credibility and quality
If you get your client’s admiration for the method and arrangements that you use for gathering and analyzing information about his project, of course you add another permanent client and get more good reputation and popularity.

Did you want your copy of advanced 
preliminary design checklist?! I hear your answer; of course yes. So, let us make a deal; just register as a follower and I will send the advanced preliminary design checklist to you by mail immediately. Is it a fair deal?! I need to know your answer in your comment. 


In the next topic, I will explain the different types of for commercial buildings and their general electrical requirements. So, please keep following. 



11 comments:

  1. Hello Eng. Ali, pls send the advanced preliminary design checklist to mail my mail address.

    ReplyDelete
  2. Hi there, I was wandering in terms of a distribution switchroom which has installed solar panels , would it be beneficial to eliminate the auxiliary transformer and utilise the solar inverter to feed the aux load, your thoughts please?

    ReplyDelete
  3. dear E. Ali
    could you pls send to me the advanced preliminary design checklist
    best regards

    ReplyDelete
  4. Please send advanced preliminary design. Thanks!

    ReplyDelete
  5. Dear Eng. Ali,
    Could you please send the advanced preliminary design checklist to mail my mail address. Thanks.

    ReplyDelete
  6. dear Engr. Ali,
    could you pls send to me the advanced preliminary design checklist.

    ReplyDelete
  7. Please check my mail regarding design checklist request.
    Regards
    Shujath

    ReplyDelete
  8. Dear Sir
    could you please add some topics on industrial power distribution in department/sector type or large industrial zone distribution and consider on energy consumption monitoring..........

    ReplyDelete

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