Something is wrong here. A normal exposure is something like 10 seconds at f11 with 82W bulb, with Ilford Multigrade IV paper. Which model of enlarger is it and what light bulb do you have? I suspect the bulb is wrong. Also, what paper and developer are you using? Is your negative of normal density (one way to check is to lay the neg on a newspaper and see if you can see the writing through the dense parts).

Jon