An electrical device like this requires a reverse leakage current of 5μA @ 20.6V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 27V.
1N4750A R1G Features
reverse leakage current of 5μA @ 20.6V 5μA @ 20.6V is the maximum voltage (Tol)
1N4750A R1G Applications
There are a lot of Taiwan Semiconductor Corporation 1N4750A R1G applications of zener single diodes.