An entire DVD TV series cannot be requested as one item, requests for the individual DVDs within a TV series have to be placed.
To place a request on a DVD in a TV series, find the series you want to request in the catalog, click on the "Place Request" button on the right next to the series. A pop-up will appear that shows where the items are located, the disc numbers, and if the item is checked in.
Next, find the disc number that you are interested in requesting within that pop-up. To the left of the disc number you will see a hand holding a book and when you hover your mouse over it, it should say place request, click on that hand to place a request on that disc number. The catalog will prompt you to enter your library account information and select a pick up location. This process will have to be repeated for ever disc that you would like to request.