Assuming there is nothing else under the floor, you can run as many as you need. But, you need to consider how high the floor is, and whether you have power cables etc under the floor.
Also you need to remember that you may have to trace the cables at some stage. I'm currently laying some cables under our computer room floor, with the help of the Bishop. We are running two bundles under our 300 mm raised floor. Both bundles have approximately 25 cat 5 cables in them.
So really, the only limitation is what you have under the floor, and how high the floor is!
Just a quick thing about tracing the cables. We are using special cables called Patchsee. They have a fibre strand inside, and with the use of a special torch they supply you can quickly trace a cable. For more information their website is
Also consider the number of outlets you can fit into your cabinet. That simply depends on how many free U your cabinet has and how many U each of your panels occupies. For example, you can get 48 way patch panels in 2U and 1U depth. But don't fill the cabinet with patch panels, allow a 1U gap after say every two panels and include a cable management strip to loom the patch cables through, otherwise you'll have unmanageable sphagetti. Also if you have active equipment in the cabinet then go a little easier on the space to allow some airflow.
As Rockape says, the number of cables you can bring into the cabinet isn't really a limitation, it's more a matter of how many you can accomodate inside
Thank you guys for your response. The computer room is new (so is the entire building), and we have a need to run about 750 cables to it. Half of them will be for phones, the other half will be for data, so the data cabinet will have active components in it. The question is should I have the 350 data cables going to 1 cabinet, or 2 cabinets, with the switches divided into 2 data cabinets. Same with the phone, with eiter active phone panels at the top, or passive phone patch panels. The floor will be raised 30 cm.
750 points sounds a lot to be going in just one cabinet, but it's hard to be prescriptive without having a much better grasp of your requirements. However here are some points for you to consider:
1) Don't try to cram everything into one cabinet just because it will fit. Consider how maintainable the patching will be in the long term (you will have moves and changes). Give yourself space to work.
2) Leave some space free in your scheme for expansion
3) Whether you go for one cabinet or two, consider the layout carefully. For example, a 'floor' port might need to patch to a switch or to a phone trunk. Where will the cables have to be run to achieve this? I suggest you draw out your layout on paper to see if it "works"
4) Some people think cross-cabinet patching (floor port outlets in one cabinet, switches and phone trunks in the other with patch leads running between) is wonderful. Others hate it with a passion (me included) and prefer to split things into blocks and keep all the patching within the cabinet. Consider your own requirements and decide which is best for you
5) Don't forget some sort of labelling or colour code or whatever to help you identify things. Choose a scheme that will make sense a year from now. For example, we use different coloured patch leads for different services
Like TheBishop says, drawing everything out is a very good idea. It lets you have an idea about how much kit will comfortably fit into a cabinet. It will also let you know if you need more cabinets. And, it comes in useful as a quick Asset Register for future use!!
Don't try and cram everything in, it will cause you heartache in the future.
The cables we use (patchsee) have a fibre strand inside them. As a result, if we need to try and trace we simply plug the "Torch" onto one end of the cable, and look for the light at the other. It is much easier that trying to trace cables through the back of a cabinet, under the floor etc.