FREE MISCELLANEOUS AND STUDY GAMES ABOUT GAS

PDF Download

FREE MISCELLANEOUS AND STUDY GAMES ABOUT GAS

HEAT UNIT 31 EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -71 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Dual-Rod (Remote) Sensing

Answer:

Uses a separate igniter and flame-sensing rod or electrode.

Question 2: Troubleshooting Flowchart

Answer:

Step by step procedures to follow when diagnosing a gas furnace problem, sequence of operation.

Question 3: Natural Gas

Answer:

A fossil fuel formed over millions of years from dead vegetation and animals that were deposited or washed deep into the earth. Methane

Question 4: Dual-In-Line Pair (DIP) Switch

Answer:

On off switches used to adjust sequencing on printed circuit boards.

Question 5: Manifold

Answer:

A device with multiple outlets or inlets controlled with valves or other devices. Typically control gases or liquids.

Question 6: Combustion Air

Answer:

Air (oxygen) used in the process of burning a fuel.

Question 7: Variable Output Thermostat

Answer:

The signal coming out changes with the temperature

Question 8: Ignition or Flame Velocity

Answer:

The rate at which the flame travels through the air and fuel mixture. The rates are different for each gas.The faster the rate the more explosive the gas.

Question 9: Horizontal Furnace

Answer:

A furnace that is layed on its side utilizing a horizontal air flow. Usually installed in a crawl space, atic or suspended from floor joists or rafters. See Multipositional Furnace

Question 10: Excess Air

Answer:

Combustion air and dilution air combined make excess air less excess air the lower the dew point

Question 11: Fan Switch

Answer:

Device to automaticaly cycle a fan on and off. Operated by temperature, time & temp, or time

Question 12: Spark-to Pilot(Intermittent Pilot)Ignition

Answer:

On a call for heat: the pilot and igniter are turned on by the ignition control, when the pilot is sensed the main burner is ignited, the system cycles off when temperature is reached.

Question 13: Gas Regulator

Answer:

Maintains proper manifold gas pressure by reducing main line to stated manifold pressure, supplying proper input to the appliance.

Question 14: Carbon Monoxide

Answer:

A poisonous, colorless, odorless,tasteless gas generated by incomplete combustion.

Question 15: Smart Valve

Answer:

Combines the gas and ignition controls in one gas valve.

Question 16: Integrated Furnace Controller(IFC)

Answer:

Controls some or all functions of the furnace, igniton, fan, fan cycles, fan speeds, A/C and accessory connections.

Question 17: Automatic Combination Gas Valve

Answer:

A gas valve for gas furnaces that incorporates a manual control, gas supply for the pilot, adjustment and safety features for the pilot, pressure regulator, and the comtrols for and the main gas valve

Question 18: Water Column (WC)

Answer:

Used to measure smaller preasure. The amount of pressure required to raise water in a tube one inch is

• inch WC

Question 19: Up-flow

Answer:

Vertical air flow through a furnace, air enters the bottom or sides and is discharged out the top.

Question 20: Bimetalic Safety Device

Answer:

A pilot safety utilizing a bimetal stirp heated by the pilot flame. When the strip is hot a contact is closed energising the gas safety valve.

Question 21: Thermocouple

Answer:

A device made of two unlike metals that generates electricity when there is a temperature difference from one end to the other. Have a hot and cold junction.

Question 22: Interpurge

Answer:

Combustion Blower operates for a period of time between tries for ignition. Interpurge happens usually when the burner doesn't light and before the next try for ignition. Heat exchangers need to be purged of unburned gas and flue gas between cycles.

Question 23: Flame Rectification

Answer:

In a gas furnace, the flame changes the normal current to direct current. The control modual will only allow the gas valve to be opened when direct current is sensed.

Question 24: Methane

Answer:

Natural gas, combustible hydrocarbon 90 to 95% pure.

Question 25: Induced Draft

Answer:

A combustion blower is located on the outlet of the heat exchanger. The blower pulls the flew gases through the heat exchanger creating a negative pressure.

Question 26: Non 100% Shut-Off

Answer:

when a flame is not sensed the main gas valve will shut off but the pilot gas will continue to flow, the ignition system will attempt to reestablish a pilot and main burner when safe.

Question 27: Heat-Motor-Controled Valve

Answer:

A heating element(coil) heats up when energized causing a bimetal to expand opening the gas valve.

Caution: this is a slow opening and closing valve.