The typical shut down sequence for a direct spark ignition system is
A) Combustion blower, indoor blower, and gas valve all de-energized simultaneously
B) combustion blower de-energized, gas valve and indoor blower de-energized after time delay
C) In door blower de-energized, gas valve de-energized after time delay, combustion blower de-energized after post purge
D) gas valve de-energized, combustion blower de-energized after post purge, indoor blower de-energized after time delay
D
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The study of or the explanation of natural phenomena is called ____________________
Fill in the blank(s) with correct word
What is the unit of the inductance?
A. Henry (H) B. Resistance Rp C. Source voltage E D. Kirchhoff's voltage law (KVL)
Which of the following locations is not permitted to be used to connect the grounding electrode at the service equipment?
A. At the weatherhead where the service drop is connected to the service-entrance conductors B. In the meter socket enclosure supplied by an underground service lateral C. In a wireway from the metering equipment to the service equipment D. In a feeder panel if immediately adjacent to the service equipment
Two materials that are considered good thermal conductors are:
A) Thermoplastic and rubber. B) Glass and ceramic. C) Paper and wood. D) Copper and aluminum.