Your Carrier 38CKC042 Air Conditioner has a cooling capacity of 3.5 Tons.
See the performance specs and cooling capacities for all different models of 38 CKC models listed at the Carrier Support page at the following link:
http://www.commercial.carrier.com/wcs/prod_physicaldata/0,2734,CLI1_DIV41_ETI4925_PRD657,00.html
And here is the Online Owner's Manual for that model from the Carrier website:
http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/OM38-51.pdf
To view the Support Page or the Owner's Manual with Operating Instructions just use your mouse to click on the link, which is the underlined and highlighted text just above. This will open a new web browser page automatically for you and allow you to view the information at the website indicated or the contents of the Owner's Manual.
You may need ADOBE READER installed on your computer to read PDF documents. You can download this free at
WWW.ADOBE.COM if necessary. Click on the DOWNLOAD ADOBE READER button on right side of the ADOBE home page when you get there, and then just follow the onscreen instructions to install it.
See the PERFORMANCE AND SIZING CHART at the support page and look beside your model (042) for the corresponding performance details, efficiency rating, dimensions, and weight.
Please comment back here to this page if you have any questions, have difficulty accessing the links, or just require further general assistance and I will respond as soon as I see it.
Thank you very much and good luck.
Joe.