A power held by a person as trustee of an express trust to make a discretionary distribution of either principal or income to such person as a beneficiary, or to make discretionary allocations in such person’s favor of receipts or expenses as between principal and income, cannot be exercised by such person unless (1) such person is the grantor of the trust and the trust is revocable by such person during such person’s lifetime, or (2) the power is a power to provide for such person’s health, education, maintenance or support within the meaning of sections 2041 and 2514 of the Internal Revenue Code, or (3) the trust instrument, by express reference to this section, provides otherwise. If the power is conferred on two or more trustees, it may be exercised by the trustee or trustees who are not so disqualified. If there is no trustee qualified to exercise the power, its exercise devolves on the supreme court or the surrogate’s court, except that if the power is created by will, its exercise devolves on the surrogate’s court having jurisdiction of the estate of the donor of the power.