GAS S F Flashcards
rating plates on appliances would most likely have an in put rating given in:
BTUH in imperial AND KW in SI (metric)
what is the minimum diameter test gauge that can be used for testing gas lines?
3”
which of the followingcould cause the regulator to supply too high an outlet pressure?
ruptured diaphragm
what is the most common cause of increased C02 in vent gases?
good combustion (co2 is a sign of efficiency)
the diagram below would utilize which type of flame detection method?
Flame rod
what is the maximum high limit setting for a low pressure steam boiler pressuretrol?
15 psig
A tube type radiant heater is considered to be __________ Intensity
low
why have flame conductivity systems not been used for proving flames?
the system will not distinguish between a flame and a short to ground.
who is responsible for instructing the customer on safe operation of appliances?
the installer of the appliance
how is a voltmeter connected to a circuit?
in parallel with power off
what may a green flame in a residential furnace indicate?
a refrigerant leak
with direct reference to a DFMAH (A direct-fired make-up air heater) utilising a M-Trac controller, what secondary function did the discharge sensor provide?
Low-limit sensor
which combustion chamber design is not suitable for conversion?
revertible
rating plate efficiency does not take into account:
combustion chamber design
what type of efficiency is used to describe the overall efficiency of an appliance?
annual fuel utilisation efficiency (AFUE)
its on a seperate sticker
the “flame spectrum” consists of:
visible, infrared and ultraviolet.
on a direct-spark ignition system, what happens after the module conducts the safe start test?
pre-purge is established
if the temperature on a forced air furnace reaches 280 deg F the most apparent problem is:
the high limit
a residential water heater that is 70% efficient , with an input of 70 MBH will heat how many imperial gallons of water in one hour?
(incoming water temperature is 34 deg F and the temperature control is set at normal.)
46.2
the proper course of action if the valve let-by is detected on a combustion gas valve is to:
replace the valve
what type of a support is required on a counter-flow furnace being installed on a combustible floor?
a factory supplied base
what is the acceptable range for the high limit setting on a conventional appliance?
180 deg F - 250 deg F
a power unit on a 600 MBH boiler that drops out at 1 mv after 155 seconds:
must be replaced
MVis too low
when using an analog meter to test a DC circuit, if the red lead was hooked up to the neutral and the black lead was hooked up to the hot, what would happen to the meter?
the needle would move backwards
Modern meters have correction for inverted lead placement
a gas pilot that is extinguished after the main flame is established would best be described as:
interrupted
all the control wiring must:
be installed in accordance with the manufacturer’s wiring diagram
a gas with high flame speed would most likely give problems with:
extinction pop
when using automatic louvres for combustion air supply to an appliance they must:
be interlocked with the main gas valve.
you have an appliance with 79% efficiency. the input is 135 MBH what is the FT3 per hour this appliance will use if its firing natural gas
135 CFH Its using all the gas
the best description of the symbal is:
combustion air switch
