Section 2--612. "Installment Contract"; Breach

(1)  An "installment contract" is one which requires or authorizes the
  delivery of goods in separate  lots  to  be  separately  accepted,  even
  though  the  contract  contains  a  clause  "each delivery is a separate
  contract" or its equivalent.
    (2) The buyer may reject any installment which  is  non-conforming  if
  the  non-conformity  substantially impairs the value of that installment
  and cannot be cured or if the non-conformity is a defect in the required
  documents; but if the non-conformity does not fall within subsection (3)
  and the seller gives adequate assurance  of  its  cure  the  buyer  must
  accept that installment.
    (3)  Whenever  non-conformity  or  default with respect to one or more
  installments substantially impairs the value of the whole contract there
  is a breach of  the  whole.  But  the  aggrieved  party  reinstates  the
  contract  if  he accepts a non-conforming installment without seasonably
  notifying of cancellation or if he brings an action with respect only to
  past installments or demands performance as to future installments.