When a capital call is completed, an investor's total capital commitment does not change, but the portion of that investor's committed capital that has been paid into the fund has increased. The fund's size (as described on the LPA) does not necessarily limit the maximum total capital investors commit - this is typically referred to as over-subscribing. 

Note that all LPs must be on the same capital call schedule and the fund cannot call and deploy 100% of the capital from a first close before raising the rest of the fund.