step 3 when the drum rotation reaches speed step 3 the effect of any dynamic imbalance may begin to appear p 3 is calculated at the third sampling window and the incremental power increase from step 2 to step 3 is calculated as a p 3 using the formula u03b4p 3 p 3 u2212 p 12 a conventional comparison of p 3 to p 3max is made as was done earlier for speed steps 1 and 2 in addition the incremental power u03b4p 3 is compared to the threshold incremental power for speed step 3 u03b4p 3l to ascertain whether a dynamic imbalance condition may appear at higher speeds if u03b4p 3 is less than u03b4p 3l then the controller takes the spin cycle to the next speed step 4 if however u03b4p 3 is greater than u03b4p 3l then the drum rotation stays at speed step 3 for the remaining spin cycle the controller may be programmed to alter the time at which the drum spins consistent with the lower rotation speed when the drum rotation reaches speed step 4 p 4 is calculated at the fourth sampling window and the incremental power increase from step 3 to step 4 is calculated as u03b4p 4 using the formula u03b4p 4 p 4 u2212 p 12 a conventional comparison of p 4 to p 4max is made.