Introduction:
- In Designing Stage , We need to calculate approximate Dimension of Electrical Panel to conclude Dimension of Electrical Room and Total Space requirement of Electrical Services.
- Dimension of Electrical Panel’s is calculated from Electrical SLD.
- Dimension of Electrical Panel mainly depends on
- Size of Main Incoming and Outgoing Circuit Barker.
- No of Outgoing Circuit Breakers.
- Panel’s Form Factor.
- Type of Panel (Indoor / Outdoor).
- Cable connection in Panel (Front Side / Back side of Panel).
- Installation of Circuit Breaker (Horizontal / Vertical)
- Height of Panel should not be more than 2200mm Due to Operation of Upmost Switchgear.
General Switchgear arrangements in Panel
- There are four compartments in Electrical Panel.
- Incoming Section
- Outgoing Section
- Busbar Chamber
- Cable Alley.
Factors to be considered to calculate Dimension of Panel:
- Dimension of Panel mainly depends on following factors.
- Type of Panel (Indoor / Outdoor):
- Depth of Panel is depending on Type of Panel.
- If We have Indoor Type of Panel and there are no any issue regarding Water seepages near Panel than Double Door type of Panel is not required.
- In Out Door Type Panel construction is mostly Double Door Type.
- For Double Door Construction required more 100mm Panel Depth than actual .
- Form Factor of Panel:
- Type of Form Factor decide Dimension of Panel.
- For Same type and same rating of Switchgear Form 1 required less space compared to Form 2A, 2B, 3A, 3B, 4A, 4B.
- Position of Switch gear Installation
- Panel’s Width and Height mostly depends on Position of Switchgear Installation.
- If we installed Switchgear in vertical Position than Height of Panel is increased.
- If we installed Switchgear in horizontal position than with of Panel is increased.
- Most of manufacture prefer Horizontal position of Switchgear to easy termination of Incoming and Outgoing of Switchgear to Busbar.
- Height of Panel
- Height of Panel should not more than 2200mm for easy operation of upmost Switchgear in Panel.
- This 2200MM height concert increase width of Panel if we have multiple number of outgoing.
- If we have 5 Nos of outgoing than it may require one No of Colum Section of Panel (400×5=2000mm).
- But if we have 8 No’s of outgoing than we required two no of Colum Section in one Section 4 no of Outgoing Switchgear and in second Colum section for 3 no of Switch gear. 1 no of More cable alley section (300mm) required for cable termination.
- Cable Termination in Panel (Front Side / Back Side)
- Front Side Cable Termination: If We Installed Panel In front of wall than Panel Back Side is not accessible hence We need Cable Termination on front side of Panel for this we need Cable Alley of 300mm for Cable Termination.
- This arrangement increase width of 300mm for panel but depth of panel will not increase.
- Back Side Cable Termination: If We Installed Panel at some distance from wall than Panel Back Side is accessible hence, we may do Cable Termination on back side of Panel for this arrangement we need more 300mm depth for Cable Termination.
- This arrangement will not increase width of panel but depth of panel will not increase 300mm.
General Compartment Size for various Switchgear in Panel.
| Size of MCB / MCCB Compartment (Cable Connections are in front of Panel) | ||||
| MCB / MCCB Size | Position | Width (mm) | Height (mm) | Depth (mm) |
| Up to 63A | Horizontal | 300 | 275 | 300 |
| 63A to 100A | Horizontal | 350 | 300 | 300 |
| 125A to 250A | Horizontal | 350 to 400 | 300 to 350 | 300 to 350 |
| 400A to 630A | Horizontal | 600 | 400 | 350 to 400 |
| MCCB 800A | Horizontal | 600 | 600 | 700 |
| MCCB 1250A to 3200A | Horizontal | 800 | 850 | 1000 |
| * Cable Connections are in front side of Panel, If Cable Connection are in Back Side of Panel add 300mm in Depth of Panel | ||||
| * Cable Termination Space in Panel (From Cable Entry at Panel to Termination Location) Up to 800A =more than 400 mm, above 800A It should be more than 800mm. | ||||
| Size of ACB Compartment (Cable Connections are in front of Panel) | ||||
| ACB Size | Position | Width (mm) | Height (mm) | Depth (mm) |
| 800A | Horizontal | 700 | 800 | 800 |
| 1600A | Horizontal | 800 | 800 | 850 |
| ACB up to 3200A | Horizontal | 800 | 850 | 1000 |
| ACB Above 3200A | Horizontal | 1400 | 1000 | 1200 |
| For Cable Entry from Bottom of Panel=Min 700mm Height from Bottom to Cable Termination | ||||
| * Cable Termination Space in Panel (From Cable Entry at Panel to Termination Location) Up to 800A =more than 400 mm, Above 800A It should be more than 800mm. | ||||
| Size of SFU Compartment (Cable Connections are in front of Panel) | ||||
| SFU Size | Position | Width (mm) | Height (mm) | Depth (mm) |
| 125A | Horizontal | 400 | 350 | 300 |
| 200A | Horizontal | 400 | 350 | 300 |
| 200A | Horizontal | 400 | 400 | 300 |
| * Cable Connections are in front side of Panel , If Cable Connection are in Back Side of Panel add 300mm in Depth of Panel | ||||
| Size of ATS Compartment (Cable Connections are in front of Panel) | ||||
| ATS Size | Position | Width (mm) | Height (mm) | Depth (mm) |
| 100A | Vertical | 400 | 700 | 350 |
| 160A | Vertical | 400 | 900 | 350 |
| 200A | Vertical | 400 | 750 | 350 |
| 400A | Vertical | 400 | 750 | 350 |
| 630A | Vertical | 400 | 1000 | 350 |
| * Cable Connections are in front side of Panel , If Cable Connection are in Back Side of Panel add 300mm in Depth of Panel | ||||
| Size of Motorized MCCB Compartment (Cable Connections are in front of Panel) | ||||||||
| Motorized MCCB Size | Position | Width (mm) | Height (mm) | Width (mm) | ||||
| 125A | Vertical | 500 | 500 | 300 | ||||
| 200A | Vertical | 500 | 500 | 300 | ||||
| 400A | Vertical | 500 | 500 | 300 | ||||
| * Cable Connections are in front side of Panel , If Cable Connection are in Back Side of Panel add 300mm in Depth of Panel | ||||||||
| Size of Starter Compartment (Cable Connections are in front of Panel) | ||||||||
| Motor KW | Position | Width (mm) | Height (mm) | Depth (mm) | ||||
| Up to 6KW | Horizontal | 500 | 300 | 300 | ||||
| 7.5KW to 11 KW | Horizontal | 600 | 200 | 300 | ||||
| 15KW to 30KW | Horizontal | 600 | 300 | 450 | ||||
| 37KW to 55KW | Horizontal | 600 | 400 | 600 | ||||
| 55KW to 132KW | Vertical | 600 | 600 | 800 | ||||
| 250KW to 300KW | Vertical | 800 | 1500 | 1000 | ||||
| * Cable Connections are in front side of Panel , If Cable Connection are in Back Side of Panel add 300mm in Depth of Panel | ||||||||
| Size of BUSBAR & Cable Alley Compartment | ||||
| Type | Position | Width (mm) | Height (mm) | Depth (mm) |
| BUS BAR | Horizontal | – | 300 to 400 | 300 |
| BUS BAR | Vertical | 300 to 400 | – | 300 |
| CABLE ALLEY | Vertical | 300 to 350 | – | 300 |
| Size of MCB Compartment (For No’s of MCB) | |||||
| MCB Size | Position | Width (mm) | Height (mm) | Depth (mm) | |
| 10A to 63A,4P MCB=5NO | Vertical | 700 | 300 | 300 | |
| 10A to 63A,4P MCB=5NO | Vertical | 700 | 300 | 300 | |
| 10A to 63A,4P MCB=3NO | Vertical | 500 | 300 | 300 | |
| 10A to 63A,4P RCCB=2NO+10A to 40A, SP MCB=20NO | Vertical | 600 | 300 | 300 | |
| 10A to 63A,4P RCCB=5NO+10A to 40A, DP MCB=2NO | Vertical | 600 | 600 | 300 | |
| 10A to 63A,4P MCB=2NO, ON/OFF | Vertical | 350 | 300 | 300 | |
| *Required 25mm to 35mm for Each Pole, Ex for Four Pole MCB required 140mm Space | |||||
Calculation-1
- Calculate Dimension of Panel for following Electrical SLD
- Cable Termination are in front side of Panel ,Cable Entry are at bottom of the Panel ,Type of Panel is Indoor Type ,Switchgear will be installed in horizontal position.
Solution:
- Incoming Switchgear= 1250A,4P, ACB
- Outgoing Switchgear = 630A, TP, MCCB=2 No and 400A, TP, MCCB=3 No’s.
- Height of Panel:
- Height of Panel is decided from No of Outgoing Feeder and Switchgear Installation Position (Horizontal / Vertical). We will Installed Switchgear in horizontal position.
- From Above Tables Height for MCCB Compartment for 400A to 630A MCCB=400mm
- Total Height of panel for 5no of MCCB= 5×400=2000mm
- Panel Base Frame is 75mm
- Total Panel height is 2000+75=2075mm which is less than 2200mm
- Width of Panel:
- Width of Panel is decided from Incoming and Out Going Switchgear Section, Cable Termination from Front / Back Side and Switchgear installation position (vertical /Horizontal).
- From above Table, Incoming Switchgear Compartment Size for 1250A,4P, ACB width is 800mm
- Size of Busbar compartment =300mm
- Size of Outgoing Switchgear compartment for 400A to 630A MCCB=600mm
- Size of Busbar alley compartment (Front Side Cable Termination) =300mm
- Total Width of Panel =800+300+600+300=2000mm
- Depth of Panel:
- Depth of Panel is decided from Incoming Switchgear (which has maximum depth) and Cable Termination in Panel (Front Side / Back Side)
- From Above Table Depth of Switchgear compartment for 1250A ,4P, ACB=800mm
- Total depth of panel=800mm
- We can also choose different depth for Incoming Switchgear compartment and Outgoing Switchgear compartment.
- In this example we can also choose depth of panel for incoming compartment=800mm and cable termination is front side of panel hence for Outgoing switchgear compartments=300mm.
- Conclusion:
- Total Width of Panel is 2000mm, Height of Panel is 2075mm, Depth of Panel is 800mm
