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67 Cards in this Set

  • Front
  • Back
a gauge that measures preassure above atmospheric and vacum below atmospheric preassure
compoung gauge
amonia absrption system

1-removes water from refrigerant
amonia absorption

2-holds strong liquor
amonia system

3-regulates liquor flow
weak liquor valve
amonia system

4-removes moisture from the vapor
amonia system

5-removes vapor from evaporator
amonia system

type of metering device used
in a booster system the second compressor is called
the primary compressor

bacause it is always started first
in a booster system the first compressor is called
the booster compressor
this stores any extra refrigerant that might be in the system and keeps it available so that the expansion valve has it when needed
two types of cooling towers
1- forced-pushes air in the tower
2-enduced-pulles air in the tower
two tipes of Brines
1-sodium choride freezing point -6.0 fh
2-calsium chloride freezing point -59.8 fh
nesslers solution
test water for amonia-turns
1-yellow for small leak
2-brown for large leak
a preasure reducing valve that controls the flow of refrigetrant to the evaporator
metering device
the most efective rust inhibitors

1-sodium bichromate
2sodium dichromate
(metering device) that is a small tank conected to the evaporator with a needle valve that regulated flow
low side float
1-maintains the preasure diferential between the condenser and the eveporator.
2-it feeds the proper amount or refrigerant to the evaporator.
3-it responds to the load change in the system
thermostatic expansion valve
installed between the compressor and the condenser,as far from the compresson as possible stops oil from entering the condenser
oil separator
device that is temperature operates the opening or closing of the metering device.inside the valve
internal equalizer (TEV)
removes moisture from system
Driers or Dehydrators

installed usually liquid line drier
remove air and other non-condesables from the system
when a preassure drop of more than 2 pounds in the evaporator you need a________in the metering device
external equalizer
a vessel or tank located in the suction line between evaporator and compressos to prevent cary over or slugging of liquid into the compressor
suction line accumulator
remove sludge,dirt,scale

installed before the compressor
filters & strainers
to check the operation and efficiency of the compressor
engine indicator
is designed to vaporize all of the low preasure liquid that passes through the evaporator
dry evaporator
the temp of the refrigerant must be _________the temp of the medium being cooled
chilled water is cooled by the refrigerant than circuleted to the apt the refrigerant never enters the apt this system is called?
indirect system
submerged below the refrigerant are tubes that carry chilled water to cool the refrigerant
flooded evaporator
(horizontal shell & tube)
(metering device)located in the receiver
higt side float
heat will always travel from the warm mass
to the cool mass
heat is rejected from the refrigeraton cycle by air or water at the____________
metering device for systems with coonstant load
water coolres,domestic ref

(constant preassure valve)
automatic expantion valve
remove noise & vibration
maitain the proper oil level in multiple compressor systems
oil equilizer lines
melts at 275 FH
fusible plug
made out of carbon or grafhite and designed to rupture at 15 PSI
rupture disk
during periods of low load the preassure drops,cutting of the compressor,it re-starts system when preasure rises
low preasure control
safety device it cuts off the system if the high side preassure exeeds a certain setting.it is not capable of re-starting the system
high preasure control
in an amonia absorbtion systen the______________acts like the compressor
the absorber
absorbtion system
the generator contains a continous sourse of__________
trouble evaporator
A-low evaporator preassure
1-dirty coil
2-dirty evaporator filter
3-supply air short cycling
4-oil logged
5-low refrigerant charge
6-paraffin based refrigerant oil
trouble evaporator
B-high evaporator pressure
1-system operating at maximum load
(max load preassure)
expansion valve wide open
trouble evaporator
low superheat
1-manual expancion valve needs re-adjusting
2-partially blocked expansion valve
3-dirty evaporator
4-too much refrigerant being sent to the evaporator
5-TEV sensing bulb
disconected from coil
trouble compressor

high suction preassure,low discharge preassure(reciprocating compressor)
compressor valves not seating properly
trouble compressor

banging sound on start up(reciprocating compressor)
oil over charge
trouble compressor

oil foaming in crankcase(reciprocating compressor)
1-crankcase heater not working
2-sudden drop in crankcase preassure
trouble compressor

compressor surging
1-high head preasure
problem condenser

low head preasure
1-condense water temp too low
2-under charge of refrigerant
problem condenser

high head preassure
1-over charge of refrigerant
2-not enough condenser water
3-condenser water temp to high
problem liquid line

frost on liquid line
partial blockege of liquid line
problem liquid line

bubbles in liquid line sigth glass
loss liquid seal

shortage of refrigerant
problem liquid line

liquid line warmer than usual
loss of liquid seal

shortage of refrigerant
problem liquid line

presence of water in the system
1-blocked flow at metering device

2-sigth glass moisture indicator turns color
(green to yellow)
problen expansion valve

TEV starved evaporator
1-external equilizer line blockage

2-broken sencing bulb

3-internally equilized TEV used on a coil with a preasure drop of more that 2.5 psi
problem expansion valve

TEV flooded evaporator
sensing bulb disconnected from from coil
problem expansion valve

AXV- starved evaporator at high load,flooded evaporator at low load
automatic control valve used in a variable load system
problem expansion valve

low side float-suction preasure rising
broken / punctured float assembly
problem expantion valve

high side float starved evaporator
broken / puntured float assembly
problems mechanical

noisy operation
worn bearings
problems mechanical

premature bearing wear/high running amps
1-belt tension too high
2-pulley out of alignment
3-coupling out of alignment
motor problems electrical

open windings
ohmmeter reads (infinity)
motor problems electrical

shorted motor windings
1-winding resistance less than the motors published value
2-less resistance causestemperature to rise,motor overload device opens circut(shut down)
motor problems electrical

short circuit to grownd
high resistance reading
use ohmmeter or megaohmmeter
motor problem electrical

icorrect rotation
reverse any two of the motor power leads
motor problem electrical

high operating temp
high corrent
cetrifugal water pump problems

pump not delivering rated GPM
1-discharge/suction valves partialy closed
2-pump air bound
3-pump cavitating
4-plugged strainer
5-piping coniguration altered
6-check valve in a parallel pump not seating properly