(a) The subsequent disability or incompetence of a principal shall not revoke or terminate the authority of any person who acts under a power of attorney in a writing executed by the principal, if the writing contains the words “this power of attorney shall not be affected by the subsequent disability or incompetence of the principal,” or words of similar import showing the intent of the principal that the authority conferred shall be exercisable notwithstanding the principal’s subsequent disability or incompetence; provided the power of attorney is executed and witnessed in the same manner as provided for deeds in section 47-5.

(b) If a conservator of the estate of the principal is appointed after the occurrence of the disability or incompetence referred to in subsection (a) of this section, the power of attorney shall cease at the time of the appointment, and the person acting under the power of attorney shall account to the conservator rather than to the principal.