Friedrich SQ05N10 Manual De Usuario

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Single Phase Resistance Test 
 
Remove the leads from the compressor terminals and set  
the ohmmeter on the lowest scale (R x 1). 
Touch the leads of the ohmmeter from terminals common  
to start (“C” to “S”). Next, touch the leads of the ohmmeter  
from terminals common to run (“C” to “R”).
Add values “C” to “S” and “C” to “R” together and 
check resistance from start to run terminals (“S” to “R”).  
Resistance “S” to “R” should equal the total of “C” to “S” 
and “C” to “R.”  
In a single phase PSC compressor motor, the highest 
 
value will be from the start to the run connections (“S” to  
“R”). The next highest resistance is from the start to the  
common connections (“S” to “C”). The lowest resistance  
is from the run to common. (“C” to “R”) Before replacing a 
compressor, check to be sure it is defective. 
GROUND TEST
Use an ohmmeter set on its highest scale. Touch one 
lead to the compressor body (clean point of contact as 
a good connection is a must) and the other probe in turn 
to each compressor terminal. If a reading is obtained the 
compressor is grounded and must be replaced.
Check the complete electrical system to the compressor 
and compressor internal electrical system, check to be 
certain that compressor is not out on internal overload. 
Complete evaluation of the system must be made 
whenever you suspect the compressor is defective. If 
the compressor has been operating for sometime, a 
careful examination must be made to determine why the 
compressor failed.  
Many compressor failures are caused by the following 
 
conditions: 
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2.    Overcharged refrigerant system causing liquid to be 
returned to the compressor. 
3.    Restricted refrigerant system. 
4.    Lack of lubrication. 
5.    Liquid refrigerant returning to compressor causing oil 
to be washed out of bearings. 
6.  Noncondensables such as air and moisture in 
 
     the system. Moisture is extremely destructive to a 
        refrigerant system.
7.     Defective capacitors. 
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