2026 QUESTIONS WITH SOLUTIONS
GRADED A+
◍ metal ductwork tends to transmit noise and fan vibrations to conditioned
spaces in residential installations. what types of connectors are specified to
control this.
Answer: flex connectors
◍ you are installing 2 sections of a rectangular sheet metal duct to main supply
line what connectors are used to secure sections of the trunk line.
Answer: S connectors and drive clips
◍ one inch of fiberglass has an R value of approx.
Answer: 3
◍ the contact points of a sequencer on a live heater may be checked by using
this meter.
Answer: voltmeter
◍ commonly used thermostat wire comes in 2 standard gauges.
Answer: 18 and 20 AWG
◍ a 1/3 single phase PSC electric blower motor would draw approx ___ at 240
v AC.
Answer: 2-4 amps
◍ a tech is installing a 3 ton cooling system with a 15 kw electric furnace. the
thermostat would require wiring a minimum of ____ conductors.
Answer: 4
◍ an electric furnace heating thermostat must.
Answer: open on rise close on drop
, ◍ the recommended minimum relative humidity for good air quality in a home
during the heating season is.
Answer: 40%
◍ the best method to install a flexible duct to a metal collar is to.
Answer: tie wrap and mastic the inner and outer liners
◍ what size copper conductor would normally be used to connect the electrical
circuit from the disconnect to a 10kW electric furnace.
Answer: 10 AWG
◍ a tech checks a fan motor run capacitor to ground with an analog ohmeter
what resistance scale should be used.
Answer: r X 10K
◍ two major factors in determining the temp rise of an electric furnace are.
Answer: furnace KW and CFM
◍ most residential AC and electric heating system will have a fan system rated
for a maxium total pressure loss of.
Answer: 0.40 - 0.50 WC (inches of water column)
◍ a motor used in an electric furnace is rated at 230 VAC what is the
minimum and maximum voltages allowed.
Answer: 207 to 253
◍ Before working on an electric furnace the tech should.
Answer: Review diagram, remove jewelry, and follow safety procedures.
ALL OF THE ABOVE.
◍ the limit switch on an electric furnace is a.
Answer: Automatic reset switch
◍ what type of safety is recommended for use with baseboard electric heat.
Answer: limit switch
◍ a major cause of electrical heat element burn out.
Answer: low airflow