Only trained, qualified installers and service mechanics should install, start up, and service this equipment. When working on the equipment, observe precautions in the literature and on tags, stickers, and labels attached to the equipment. Before installation, always check to be sure main power to systems are OFF. Electrical shock can cause personal injury or death. GENERAL The MDEH1 dehumidistat is used with Totaline SHR series heat recovery ventilators. See Fig. 1. The dehumidistat is used to