Carrier 38AJ 008, Installation, Operation And Maintenance Instructions

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12
Pressure differential (difference between cylinder
load point and unloader points)
Turn the adjusting screw
햵
counter-clockwise to its back stop
position. In this position the differential is 41 kPa. The pressure
differential is set by turning the adjusting screw clockwise. Each
full turn increases the differential by 10 kPa. Approximately 10
turns clockwise will increase the pressure to 152 kPa.
The capacity control factory settings for 4-cylinder units are:
475 kPa gauge control setpoint (cylinder load point), 70 kPa
differential, 405 kPa gauge cylinder unload point.
The settings for 6-cylinder units are: the left cylinder bank
setpoint is 482 kPa gauge (70 kPa differential); the right
cylinder bank setpoint is 469 kPa gauge (70 kPa differential).
Fig. 7 - Pressure-operated control valve
Modifications
It is possible to convert pressure-controlled capacity reductions to electrically controlled reductions or to add capacity reductions
in accordance with the table below.
38AJ/AZ Pressure-controlled Possibility of changing Possibility of 2
unloader standard press. to electric unloader pressure-contr. unloaders
008 - - -
010 - - -
012 - - -
014 yes yes yes
018 yes yes yes
024 yes yes yes
030 yes yes yes
036 yes yes yes
046 yes yes yes
062 yes yes yes
074 yes yes yes
Low and high pressure switch control and condensing pressure pressostat control
Pressostat control: High pressure, kPa Low pressure, kPa Condensing pressure, kPa
38AJ/AZ Opens Closes Opens Closes Opens Closes
008-012 2500 2150 50 150
014-036 2900 2200 50 150 870 1820
046-074 2900 2500 240 390 870 1820
Legend:
1
Control setpoint adjustment screw
2 Valve body
3 Sealing cap (covering the differential adjustment screw)
4 Differential pressure adjustment screw