After an intense and very demanding team effort, we completed the design, development and Certification of our Single-phase voltage protection for AC powered refrigerators and freezers. Our certified stabilizers model names are PPS_MFS-Lw (230V-50/60Hz ) and PPS_MFS-LwE(120V-50/60Hz). The PQS prequalification system was created and managed by the world’s largest health organization that specifies and verifies the critical criteria and minimum performance of immunization equipment, including refrigerators, temperature monitors and voltage stabilizers. Inconsistent and unstable electrical quality power to be a major contributing factor to the breakdown of mains-powered refrigerators and freezers used for immunization in resource constrained settings.