York YPAL 060 User Manual

Page of 168
154
JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
Service
DIFFERENTIAL INPUT
PRESSURE - IWC
OUPTUT VOLTAGE - VDC
-0.50
0.00
-0.40
0.50
-0.30
1.00
-0.20
1.50
-0.10
2.00
0.00
2.50
0.10
3.00
0.20
3.50
0.30
4.00
0.40
4.50
0.50
5.00
TABLE 8-3 – BUILDING PRESSURE TRANSDUCER OUTPUT
TABLE 8-2 – DUCT PRESSURE TRANSDUCER
1.25" WC SPAN
DIFFERENTIAL
INPUT PRESS
2.5" WC SPAN
DIFFERENTIAL
INPUT PRESS
5.0" WC SPAN
DIFFERENTIAL
INPUT PRESS
VOLTAGE
VDC
0.125
0.25
0.5
0.50
0.25
0.50
1.0
1.00
0.375
0.75
1.50
1.50
0.50
1.00
2.00
2.00
0.625
1.25
2.50
2.50
0.75
1.50
3.00
3.00
0.875
1.75
3.50
3.50
1.00
2.00
4.00
4.00
1.125
2.25
4.50
4.50
1.25
2.50
5.00
5.00
Building Pressure Transducer
The Building Pressure Transducer is located behind the 
right hand damper door.  The purpose of the transducer is 
to sense and convert the static pressure in the building to 
a 0 to 5 volt DC voltage.  The DC voltage is then sent to 
the Unit Controller and compared against the “BUILDING 
PRESSURE ACTIVE SETPOINT”
.  The transducer is 
factory wired, but pneumatic tubing must be fi eld supplied 
and installed (refer to Section 2 “INSTALLATION” in this 
manual).  
 The Building Pressure Transducer measures 
differential pressure in the building and atmospheric 
pressure.  When verifying transducer operation, the 
technician can inset a tee into the pneumatic tubing and 
connect a manometer to the tee to verify the pressure being 
applied to the transducer.  Once this pressure is known, a 
comparison can be made of the building pressure vs. output 
volts DC from the transducer.  A practical and quick check 
of this transducer can also be accomplished by removing 
the pneumatic tubing lines from both the low and high side 
connections on the transducer.  Since both of the inputs 
will now be exposed to the same pressure, the differential 
pressure will be zero, and the output 2.5 volts DC according 
to Table 8-3.
Return Fan Pressure Transducer
If the unit is order with the Return Fan Option the 
unit will have a Return Fan Pressure Transducer.  The 
transducer is behind the right hand damper door and 
compares the pressure in the return air compartment to 
atmospheric pressure.  The Unit Controller varies the 
speed of the Return Fan in order to maintain the correct 
differential pressure in the return compartment.  When 
verifying transducer operation, the technician can inset a 
tee into the pneumatic tubing and connect a manometer 
to the tee to verify the pressure being applied to the 
transducer.  Once this pressure is known, a comparison 
can be made of the return compartment pressure vs. 
output volts DC from the transducer.  A practical and 
quick check of this transducer can also be accomplished 
by removing the pneumatic tubing lines from both the 
low and high side connections on the transducer.  Since 
both of the inputs will now be exposed to the same 
pressure, the differential pressure will be zero, and the 
output 2.5 volts DC according to Table 8-4.
DIFFERENTIAL INPUT
PRESSURE - IWC
OUPTUT VOLTAGE - VDC
-1.00
0.00
-0.80
0.50
-0.60
1.00
-0.40
1.50
-0.20
2.00
0.00
2.50
0.20
3.00
0.40
3.50
0.60
4.00
0.80
4.50
1.00
5.00
TABLE 8-4 – RETURN FAN PRESSURE 
TRANSDUCER OUTPUT
Discharge Pressure Transducer
The discharge Pressure Transducer is located in the 
common discharge line of the tandem compressors for 
each refrigerant circuit.  The purpose of this transducer 
is to sense and convert the discharge pressure into a 
DC voltage.  The DC voltage is then sent to the Unit 
Controller where it is used to control the number of 
condenser fan when the unit is in cooling operation.  
The discharge pressure value, in PSIG, is displayed by 
the User Interface.