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HVACR gas heating esco Questions & 100%
Verified Answers | Latest Update | Already
Graded A+
using an ohmmeter, there is 120 VAC between high speed and ground wires, this indicates ๐ธ๐ธ๐ธ : open if temperature rise is too high... ๐ธ๐ธ๐ธ : increase fan speed how many of the 3 OSHA conditions defining confined spaces must be met ๐ธ๐ธ๐ธ : all 3 what causes the temperature limit safety switch to shut off the burner ๐ธ๐ธ๐ธ : fan motor failure flashback indicates ๐ธ๐ธ๐ธ : the gas is flowing slower than the speed at which burn is occurring what type of connector is used to control noise in ductwork
๐ธ๐ธ๐ธ : vibration eliminators if the main burner lights and after a minute the blower fan comes on but the burner flames waver in one corner... ๐ธ๐ธ๐ธ : there is faulty blower housing a burner orifice... ๐ธ๐ธ๐ธ : meters gas to the burner when lockout/tagout is used ๐ธ๐ธ๐ธ : there should be 1 key kept by the electrician the gas pressure is usually ๐ธ๐ธ๐ธ : 3. a spark igniter operates at ๐ธ๐ธ๐ธ : 7,500 vac a good thermocouple produces ๐ธ๐ธ๐ธ : 30 millivolts what must be present for combustion
to change cubic feet per minute delivered to a single speed belt driven blower, you should adjust ๐ธ๐ธ๐ธ : the motor pulley size nitrogen combines with oxygen to form... ๐ธ๐ธ๐ธ : NOX when the burners are ignited, the blower is delayed to... ๐ธ๐ธ๐ธ : allow the heat exchanger to warm up gas piping must be installed with a pitch of ๐ธ๐ธ๐ธ : 1/4 inch per 15 ft pipe joint compound should be applied to ๐ธ๐ธ๐ธ : the male threads, not last 2 threads if voltage is applied across 2 speed terminals on a fan motor at the same time, the motor ๐ธ๐ธ๐ธ : runs too fast what is the result of an oversized mid efficiency furnace
๐ธ๐ธ๐ธ : the heat exchanger corrodes what draft moves flue gas through the heat exchange ๐ธ๐ธ๐ธ : mechanical furnace designed with the blower motor under the heat exchange is the ๐ธ๐ธ๐ธ : upflow a gas furnace is installed in a garage, the burners are ๐ธ๐ธ๐ธ : 18 inches above floor a carryover on a gas burner.. ๐ธ๐ธ๐ธ : provides smooth lighting of all burners 100% shutoff means ๐ธ๐ธ๐ธ : gas to the pilot and manifold are shut off a limit switch deenergizes the ๐ธ๐ธ๐ธ : gas valve if it overheats what checks the pressure of a furnace ๐ธ๐ธ๐ธ : manometer
the volts of a hot surface igniter is ๐ธ๐ธ๐ธ : 120 volts thermostats contain 1+ sets of contacts to control heating, they are ๐ธ๐ธ๐ธ : thermally actuated adjustable shutters ๐ธ๐ธ๐ธ : mix primary and gas 60000 btu/h operating at 50% air ๐ธ๐ธ๐ธ : 600 cu ft vent stack temp on a natural draft furnace is ๐ธ๐ธ๐ธ : 350 - 450 f 1/2 and 3/4 black pipe is installed, cut how many threads ๐ธ๐ธ๐ธ : 10 - 12 a furnace with the blower motor above the heat exchanger is a ๐ธ๐ธ๐ธ : downflow ASHRAE specify how much CO
๐ธ๐ธ๐ธ : 9 ppm air mixed with natural gas is ๐ธ๐ธ๐ธ : primary air severity of shock is determined by ๐ธ๐ธ๐ธ : intensity of flow and path external static pressure is ๐ธ๐ธ๐ธ :. 2 -. 6 in WC condensing furnaces work at ๐ธ๐ธ๐ธ : 90% LP has a gravity og ๐ธ๐ธ๐ธ : 1.5-2. pressure drop in natural gas piping is due to ๐ธ๐ธ๐ธ : friction or resistance a cat 4 2 pipe vent system thru roof has an elbow that ๐ธ๐ธ๐ธ : points down
the pilot assembly orifice is clogged ๐ธ๐ธ๐ธ : replace natural gas consists of ๐ธ๐ธ๐ธ : methane gas burners change diameter, referred to as ๐ธ๐ธ๐ธ : ventiru defective heat exchanger ๐ธ๐ธ๐ธ : inform homeowner and turn off supply of gas to furnace LP gases are ๐ธ๐ธ๐ธ : propane, butane flue baffle ๐ธ๐ธ๐ธ : increases heat exchange ignition temp of natural gas ๐ธ๐ธ๐ธ : 1100 - 1200
to test flame rectification ๐ธ๐ธ๐ธ : placemeters in series with flame sensor to test DC microamps 0 ohms b/w common and low speed wirings, winding is ๐ธ๐ธ๐ธ : shorted igniter in a hot surface ignition furnace doesnt energize ๐ธ๐ธ๐ธ : check for voltage thru pressure switch if a furnace makes a loud bang upon ignition ๐ธ๐ธ๐ธ : check supply to gas pressure testing resistance of a hot surface igniter ๐ธ๐ธ๐ธ : allow igniter to cool constant airflow, torque, and speed are types of ๐ธ๐ธ๐ธ : ECM motors
