HVAC Excellence Commercial Air Conditioning ESCO
Certification
1. Multiple compressor systems have a equalization line A. Maintain
equal loads on
to; tested and
A. Maintain equal loads on all compressors repaired.
B. Maintain equal oil levels on all compressors. B.)restricte
C.Compensate for different pressures in the d return
compres- sors. air flow
or a
D. Compensate for evaporator pressure drop.
dirty
evapora
2. The purpose of a double suction line riser is to; tor
A. maintain minimum refrigerant
velocities under varying loads.
B. compensate if one suction filter - drier
becomes plugged.
C. prevent low pressure trips on start up.
D. compensate for evaporator pressure drop.
3. To measure superheat, subtract the;
A. low side saturation temperature from the
suction line temperature.
B. high side condensing temperature from the
suction line temperature.
C.suction line temperature from the ambient
temper- ature.
D.ambient temperature from the suction line
temper- ature
4. An air conditioning system is running
constantly, but not cooling enough. The
suction line is very cold and the compressor is
sweating. This is an indication of;
A.)low refrigerant charge and needs to be leak
, HVAC Excellence Commercial Air Conditioning ESCO
Certification
all compressors
A. maintain minimum re- frigerant velocities under varying loads.
A. low side saturation tem- perature from the suction line temperature.
B.) restricted return air flow or a dirty evaporator
, HVAC Excellence Commercial Air Conditioning ESCO
Certification
C. restricted air flow across the condenser.
D.) damaged return air duct allowing
unconditioned air to be drawn into the
system.
D. To remove
5. Why must a cooling tower or evaporative concentra- tion of
condenser be blown down periodically? minerals in the wa- ter.
A. The condenser water approach will begin
to nar- row.
B. Maintain PH level of the circulated water.
C. To refresh cooling tower or condenser with
cooler make-up water.
D. To remove concentration of minerals in the
water.
6. A customer reports that their system had one of three B. the new
motor is grossly
fan motors replaced last week by another service com- over sized.
pany. Now the unit is not cooling properly
since the outdoor temperature has risen.
When you arrive and inspect the unit, you find
that discharge pressure is very high. On further
examination, all motors are run- ning, but the
amp draw is different on the new motor as
compared to the other two motors. This is
most likely the result of:
A. fan motor is running backward
B. the new motor is grossly over sized.
C. a defective replacement motor.
D. , the fan blade was not changed to match
the new motor
7. When pumping down a condensing unit to check the
, HVAC Excellence Commercial Air Conditioning ESCO
Certification
reciprocating compressor valves, the B. 30" Hg suction
compressor should be able to achieve; when discharging to
A. 10" Hg suction with a 300 psig high side the atmos- phere.
pressure.
Certification
1. Multiple compressor systems have a equalization line A. Maintain
equal loads on
to; tested and
A. Maintain equal loads on all compressors repaired.
B. Maintain equal oil levels on all compressors. B.)restricte
C.Compensate for different pressures in the d return
compres- sors. air flow
or a
D. Compensate for evaporator pressure drop.
dirty
evapora
2. The purpose of a double suction line riser is to; tor
A. maintain minimum refrigerant
velocities under varying loads.
B. compensate if one suction filter - drier
becomes plugged.
C. prevent low pressure trips on start up.
D. compensate for evaporator pressure drop.
3. To measure superheat, subtract the;
A. low side saturation temperature from the
suction line temperature.
B. high side condensing temperature from the
suction line temperature.
C.suction line temperature from the ambient
temper- ature.
D.ambient temperature from the suction line
temper- ature
4. An air conditioning system is running
constantly, but not cooling enough. The
suction line is very cold and the compressor is
sweating. This is an indication of;
A.)low refrigerant charge and needs to be leak
, HVAC Excellence Commercial Air Conditioning ESCO
Certification
all compressors
A. maintain minimum re- frigerant velocities under varying loads.
A. low side saturation tem- perature from the suction line temperature.
B.) restricted return air flow or a dirty evaporator
, HVAC Excellence Commercial Air Conditioning ESCO
Certification
C. restricted air flow across the condenser.
D.) damaged return air duct allowing
unconditioned air to be drawn into the
system.
D. To remove
5. Why must a cooling tower or evaporative concentra- tion of
condenser be blown down periodically? minerals in the wa- ter.
A. The condenser water approach will begin
to nar- row.
B. Maintain PH level of the circulated water.
C. To refresh cooling tower or condenser with
cooler make-up water.
D. To remove concentration of minerals in the
water.
6. A customer reports that their system had one of three B. the new
motor is grossly
fan motors replaced last week by another service com- over sized.
pany. Now the unit is not cooling properly
since the outdoor temperature has risen.
When you arrive and inspect the unit, you find
that discharge pressure is very high. On further
examination, all motors are run- ning, but the
amp draw is different on the new motor as
compared to the other two motors. This is
most likely the result of:
A. fan motor is running backward
B. the new motor is grossly over sized.
C. a defective replacement motor.
D. , the fan blade was not changed to match
the new motor
7. When pumping down a condensing unit to check the
, HVAC Excellence Commercial Air Conditioning ESCO
Certification
reciprocating compressor valves, the B. 30" Hg suction
compressor should be able to achieve; when discharging to
A. 10" Hg suction with a 300 psig high side the atmos- phere.
pressure.
