what is an example of an input for an hvac controller
humidistat
what is an output of an hvac controller
blower motor
a 2 wire thermostat would be commonly used for what equipment
basic furnace
acronyms for hvac control systems
DDC BAS EMS ECS FMS
what are 7 wire thermostats used for
combination heating and cooling with 2stage heat and 2stage cooling
5 wire thermostat use ?
combination heating and cooling
what terminals are jumpered together in 5 wire and 7 wire thermostats
Rh and Rc terminals
terminal g
fan control
terminal Rc
power connection for cooling
terminal Rh
power connection for heating
describe free cooling
uses outside air when both temp and humidity are suitable to cool, saves energy
what does intermittent ignition include
direct spark ignitor, pilot light
most common type of burner assembly for hvac rooftop unit
In- shot burner
the 3 sections of a roof top unit
heating, cooling, ventilation
Where are rollback switch located in hvac rooftop unit
Near the burners and gas manifold N.C
A normally closed pressure switch that is located in the compressor discharge line and wired in series with compressor and contractor coil
High-pressure switch
A normally open pressure switch located in the compressor suction line
Low-pressure switch
the cooling section of a hvac rooftop unit include
compressor, condensing fan, condensing coil
a heating section of hvac rooftop unit include
gas valve, burners, heat exchanger, ignition system
when a roof top unit receives a call for heat what component starts first
combustion blow motor
