Multiple Choice 2 points What is a method of checking the flame rectification circuit to sense the flame in gas furnaces? Check for DC amps by placing the amp-on ammeter around the wire to the flame rod Check for DC microamps by placing a microammeter in series with the flame rod or system ground Check to see if 24 volts is being supplied to the flame sensor using an AC voltmeter Check for DC microvolts using a voltmeter Multiple Choice 1 point If the voltage loss measured across the contacts of a contactor is more than 5% of the line voltage, the contactor is good Has a faulty coil is too large for the application should be replaced Ey Multiple Choice 1 point A service technician should never leave a conditioned air system with a safety control device ; Jumped-out All of the choices are correct Removed from the circuit Replaced with the incorrect part Multiple Choice 1 point What is a disadvantage of using aluminum conductors? Aluminum is heavy and not very flexible Aluminum corrodes easily and the connections may become loose over time Aluminum is much more expensive that copper Aluminum is a poor conductor of electricity ge Multiple Choice 1 point Which of the following choices can be used as a source of supplementary heating for a heat pump system? Gas furnace Electric resistance heaters All of the choices are correct Oil furnace