We have investigated the possibility of nitrogen involvement in the formation of the Z(1)/Z(2) defect in 4H-SiC. A recent model suggests that nitrogen together with carbon interstitial-like defects is responsible for this deep center. This possibility was tested by irradiation of phosphorus doped epilayers with low residual nitrogen concentration. Nitrogen doped epilayers with similar doping concentration were used for comparison. Irradiation yields identical DLTS spectra for both phosphorus and nitrogen doped samples; the Z(1)/Z(2) peak occurs at the same temperature and its concentration is independent of the dopant. The concentration of the Z(1)/Z(2) defect in irradiated phosphorus doped samples exceeds the atomic nitrogen concentration by nearly one order of magnitude. No saturation of the concentration of the Z(1)/Z(2) defect or other irradiation induced defects was observed. We conclude that nitrogen atoms do not participate in the formation of the Z(1)/Z(2) defect.