The type of material often used for the resistance wire in electric heat is?
nickle chromium
Portable or small space heates with glowing coils transfer heat by?
radiation
Baseboards heaters transfer heat by?
CONVECTION
A disadvantage of a central forced air electric furnance is?
there is no zone control for individual rooms
Three common controls used in central electric heat applications are thermostats, contactors (or relays), and ?
sequencers
The low voltage thermostat is used for central electric heat because it is compact, it is responsive and it is?
safe, easy to install and troubleshoot.
The heat anticipator setting is determined by?
adding all the current draws in the 24volt circuit that passes through the thermostat control bulb and heat anticipator.
The sequencer uses ______________(high or low) voltage control power to stop and start the electric heaters?
low
True or False. A package sequencer can start or stop only one stage of strip heat.
False
Two stages of wiring diagrams are the pictorial and ________________.
Schematic
The limit switch shuts off the the unit if
high temperature occurs.
The _______ wire from the transformer furnishes power to the thermostat.
Red Wire
State the formula used for detemining the cubic feet per minute (cfm) airflow across the furnace heating elements?
cfm=Qs/1.08 x temperature difference
Power consuming devices are wired in?
Parallel
Power passing devices are wired in?
Series
Radiant heat is transferred by?
Infrared rays
Most electric baseboard units are __________ heaters.
Natural-draft convection
Central forced-air electric furnances frequently use ______________ to start and stop multiple heating circuits.
Sequencers
A sequencer often utilizers a ______________ to initiate its operation.
bimetal heat motor or bimetal snap disc
The componet located in the thermostat that shuts the electric furnance down prematurely so that the space will not overheat is ____________.
heat anticipator
The disadvantage in using a contactor to open and close the circuit to the electric heating elements is?
1.) A large current draw when the conteactor coil is energized
2.) heating elements all starting at the same time unless separate time delays were used.
A limit switch or control is used to?
Open the circuit to the heating elements if the furnance overheats.
Electric unit heaters are usually installed on the?
Ceilings or on the walls
Electric ceiling panel heat?
is a radiant type heat
The _______ thermostat is commonly used for forced-air electric furnance installations.
low-voltage
The __________ is commonly used for the the baseboards electric heat installations.
High-voltage
The controll voltage for a sequencer is?
24volts
Electric heat is produced by what?
Converting electrical energy to heat.
Two safety devices found on electric furnaces are?
Limit switches and fuse links