Estimating number of Marshalling and System cabinets

[olame]

Please does any one know any application or spreadsheet for quickly estimating the number of Marshalling and System cabinets required for a DCS control system- assuming the number of I/O s to be terminated are known ?

 

[controlnovice]

I don't know of anything simple like a spreadsheet for this.
Suggest using the DCS/PLC vendor to help.
So many questions:

Size of room?
Height of room?
incoming cables above or below?
are cables single pair or multiple pair in larger cable?
conduit entry or cable?
What size terminal strip do you want?
Where are cables going? What type of cable connection?
Are DCS/PLC terminal boards mounted in cabinets?
Power supplies? DC or UPS involved?
is wiring mixture of intrinsic safe and 'normal' (need separation?
will analog and digital be mixed? 24Vdc, 120Vac, 220Vac, 12Vdc?
Too many more questions to list....but you get the idea.


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[olame]

Thanks Controlnovice for the reply, I agree all those issues you higlighted are critical for a good detailed estimate. But my question really is that is there a tool for an un-constrained estimate? sometimes at the very early stage of a project, you want to do an un-constrained estimate of required equipment just to have the big picture and build up your feasibility. You are right some control system manufacturers have done this for us in the past, but if I am able to do this in-house I will have more flexibility to do sensitivities for different scenarios.

 

[controlnovice]

+/- 50% budgetary estimate/preliminary design?

Still don't know of a spreadsheet.

I'd probably use 100 - 120 I/O per side of a 48x72" cabinet. Doesn't sound like much, but with wireways, power supplies, etc..., space gets used up quickly.



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