HVAC 101-Heating Fundamentals and Answers for Final Exam Questions And Answers

What is an SSU and what does it do? - ans-It is a unit located on the side of the first which receives power (120 volts) before anything located within the furnace itself. It primarily consists of a switch and a fuse, and it is what allows for power to flow to the door switch. Opening the switch on the SSU will cut power to everything within the furnace. What is an OCPD? Describe its function in detail. - ans-An OCPD is an Over-Current Protection Device, and it will protect conductors and equipment against excess heat generated by over-current within the circuit as a result of overloads, short-circuits, or ground faults. What does "FR" mean, and why is it important to the Sequence of Operations? - ans-The abbreviation "FR" stands for Fan Relay, and it is important to the Sequence of Operation because it is allows for the fan to run in order to satisfy the call for heat at the thermostat. What is the inlet gas pressure to Gas Valve? - ans-7 What is the outlet gas pressure for the Manifold? - ans-3.5 What is the IDR? How does it function? - ans-The IDR is the Induced Draft Relay, and this is what will supply the IDM (Induced Draft Motor) with power in 120 volts when its coil is energized by 24 volts during the call for heat at the thermostat when the r and w contacts therein connect. What is the IDM? How does it function? - ans-The Induced Draft Motor, sometimes known as a Combustion Blower, has two primary functions with in a gas furnace. Its first function, which applies to the Sequence of Operation, allows for air to move from the Heat Exchanger and out the Structure Flu