Sec. 612. (1) An "instalment 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 instalment which is non-conforming if the non-conformity substantially impairs the value of that instalment 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 instalment.
(3) Whenever non-conformity or default with respect to one (1) or more instalments 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 instalment without seasonably notifying of cancellation or if he brings an action with respect only to past instalments or demands performance as to future instalments.