Navy Rates (but not limited to): Electronics Technician (ET), Machinists Mate (MM), Electricians Mate (EM), Missile Technician (MT), Information Systems technician (IT), Aviation Electronics Technician (AT), Aviation Antisubmarine Warfare Technician (AX), Torpedoman’s Mate (TM), Sonar Technician (ST), and All Nuclear reactor rates (MMN, EMN, ETN). Understand mechanical, electrical or controls operations of HVAC/R systems, including chiller plants, compressed air, heating water, cooling water, process exhaust, cleanroom HVAC/R, and general building HVAC/R.