Esco Heat pump exam Questions AND Correct Answers
___________________________- _____________________---
is used to defrost the outdoor coil for a heat pump? - ✔✔hot
gas
_______________________-
is the difference between synchronous (calculated) speed and
actual speed; that speed difference is caused by the load or
work being done. - ✔✔slip
_______________VA to________ VA is the most common
rating for control transformers used in residential heat pump.
- ✔✔40 ,50
A check valve must be place around the metering device on
the outside coil (Heating Mode) - ✔✔Installed in parallel,
arrow against the flow of refrigerant
A check valve must be placed around the metering device on
the inside coil (Heating Mode) - ✔✔Answer:
Installed in parallel, arrow with the flow of refrigerant
,A crankcase heater will heat the compressor crankcase to
______. This will keep liquid refrigerant in the evaporator
from migrating into the compressor crankcase. - ✔✔20°F
warmer than ambient
A defrost thermostat closes its contacts at approximately
°F and opens at about
°F. (numerical valve only) - ✔✔32.45
A large footprint unit moves - ✔✔little air
A measurement of the speed or motion of molecules in a
substance called. - ✔✔temperature
A small footprint unit will have to move - ✔✔a lot of air
A time, temperature and pressure defrost control is called
demand defrost. - ✔✔true
A vacuum at 29.92" Hg is a perfect vacuum. - ✔✔false
,Air to Air heat pumps are capable of production COP ranges as
high:
Incorrect answer:
1:1 - ✔✔3.5:1
Air to air heat pumps are normally sized to the - ✔✔cooling
load
Airflow across the evaporator should be - ✔✔450 cfm/ton
An air cooled evaporator evaporates liquid to a vapor at -
✔✔35 below ambient
Approximately how many electric heat strips are energized
with one set of contacts on a sequencer? - ✔✔1 for a timed
stage
Approximately what size liquid and suction line would be used
on a four-ton heat pump with a 40-foot line set? (numerical
value only, use dividing symbol for fraction (/), if whole
number and fraction type as number, space, number, dividing
symbol, number i.e. 5 4/9) - ✔✔3/8 7/8 1 1/2
, Approximately what size liquid and suction line would be used
on a two-ton heat pump with a 20-foot line set? (numerical
value only, use dividing symbol for fraction (/)) - ✔✔3/8 3/4
Approximately what temperatures does a defrost thermostat
close
__________ and open ____________ to
____________---
its contacts - ✔✔
As outdoor temperature decreases, the COP - ✔✔decrease
As refrigerant absorbs heat, it changes from a
__________________ to a _______________
. - ✔✔liquid vapor
Atmospheric pressure is
______________
psia at sea leve - ✔✔14.7
___________________________- _____________________---
is used to defrost the outdoor coil for a heat pump? - ✔✔hot
gas
_______________________-
is the difference between synchronous (calculated) speed and
actual speed; that speed difference is caused by the load or
work being done. - ✔✔slip
_______________VA to________ VA is the most common
rating for control transformers used in residential heat pump.
- ✔✔40 ,50
A check valve must be place around the metering device on
the outside coil (Heating Mode) - ✔✔Installed in parallel,
arrow against the flow of refrigerant
A check valve must be placed around the metering device on
the inside coil (Heating Mode) - ✔✔Answer:
Installed in parallel, arrow with the flow of refrigerant
,A crankcase heater will heat the compressor crankcase to
______. This will keep liquid refrigerant in the evaporator
from migrating into the compressor crankcase. - ✔✔20°F
warmer than ambient
A defrost thermostat closes its contacts at approximately
°F and opens at about
°F. (numerical valve only) - ✔✔32.45
A large footprint unit moves - ✔✔little air
A measurement of the speed or motion of molecules in a
substance called. - ✔✔temperature
A small footprint unit will have to move - ✔✔a lot of air
A time, temperature and pressure defrost control is called
demand defrost. - ✔✔true
A vacuum at 29.92" Hg is a perfect vacuum. - ✔✔false
,Air to Air heat pumps are capable of production COP ranges as
high:
Incorrect answer:
1:1 - ✔✔3.5:1
Air to air heat pumps are normally sized to the - ✔✔cooling
load
Airflow across the evaporator should be - ✔✔450 cfm/ton
An air cooled evaporator evaporates liquid to a vapor at -
✔✔35 below ambient
Approximately how many electric heat strips are energized
with one set of contacts on a sequencer? - ✔✔1 for a timed
stage
Approximately what size liquid and suction line would be used
on a four-ton heat pump with a 40-foot line set? (numerical
value only, use dividing symbol for fraction (/), if whole
number and fraction type as number, space, number, dividing
symbol, number i.e. 5 4/9) - ✔✔3/8 7/8 1 1/2
, Approximately what size liquid and suction line would be used
on a two-ton heat pump with a 20-foot line set? (numerical
value only, use dividing symbol for fraction (/)) - ✔✔3/8 3/4
Approximately what temperatures does a defrost thermostat
close
__________ and open ____________ to
____________---
its contacts - ✔✔
As outdoor temperature decreases, the COP - ✔✔decrease
As refrigerant absorbs heat, it changes from a
__________________ to a _______________
. - ✔✔liquid vapor
Atmospheric pressure is
______________
psia at sea leve - ✔✔14.7
