A well pump electrical motor has a motor housing filled with a dielectric motor lubricant. A motor head has at least one motor lead passage in fluid communication with the motor lubricant. An outer seal, which is exposed to well fluid, seals around a motor lead in the motor lead passage. An inner seal seals around the motor lead in the motor lead passage inward from the outer seal and has an inner side in contact with the motor lubricant in the motor. A barrier fluid passage extends into an annular space between the inner and outer seals and contains a barrier fluid. A pressure compensating device has an inner side in contact with the barrier fluid in the barrier fluid passage for reducing a pressure differential between the barrier fluid and a hydrostatic fluid pressure of well fluid on the exterior of the motor.