Spare capacity in any system is always essential, especially when networks are required to grow and your switchgear must be able to withstand such growth, therefore there are two main considerations when detailing the requirements of 'Spare Capacity':

 

• Percentage

• Unpopulated Compartment, Populated Fixed MCCB's,  Unpopulated Plugin/Withdrawable Base, Populated Plugin/Withdrawable Base

 

Spare capacity is generally detailed as a percentage, typically 20% or 25%, however, this is typically exclusive to each project and therefore is essentially future proofing your switchgear for expansion at a later stage. It is important to get this right as extension sections can be very costly and also require extra space in the switch room to either the right of left of the switchboard.

Once you have considered your percentage application it's worth considering your options from how your detailed percentage is manufactured. Typically you have a few options:

 

How do I specify what I want?

 

• Unpopulated Compartment - Copper Connections only, fitted within the compartment and blanked off for future application.

 

This is the cheapest option and leaves copper connections within the compartment to accept a future breaker, the main thing to note here that the board typically would require complete isolation to fit future breakers

 

• Populated Fixed MCCB Device - MCCB fixed devices fitted to each spare compartment for future applications.

 

It’s worth stating what device you want, if this is the option you choose typically I would advise fitting the top of the range breakers, by this the largest current rating for that frame size, for example, Schneider’s 250A breaker is the largest frame of that physical device, this giving you the advantage of fitting lesser trip units in the breaker.

 

• Unpopulated Plugin/Withdrawable Base - Plugin base device fitted to each spare compartment for future applications.

 

Plugin devices for spares are very common and mean that isolation of the switchboard when retrofitting devices is not required, therefore the application can be completed while the switchgear remains live, therefore making this quite an attractive solution for critical applications.

 

• Populated Plugin/Withdrawable Base - Plugin base device and MCCB fitted to each spare compartment for future applications.

 

This application is exactly the same as above, however, this also includes for the actual breaker and means all the parts are ready to accept load and spare breakers can be swapped depending on size and rating (Please check with the manufacturer or us for more details)