Specifications

62
JOHNSON CONTROLS
Form 201.28-NM1.EN.PED/CE (0211)
OPERATION
Eductor Clog Fault
To sense a loss of oil return to the compressor, an eductor
clog detection safety is utilized. The safety monitors
the temperature of the line between the eductor and the
suction line.
The control algorithm looks at the eductor line
temperature once a second. At start, a clog timer is set at
600 seconds. If the eductor line temperature is less than
the saturated suction temperature plus 5.5°C (10°F) each
time the control circuit looks at the temperature, the clog
timer is reset to 600 seconds.
If the eductor line temperatures is greater than the
saturated suction temperature plus 5.5°C (10°F), the
clog timer is decremented one second. If the temperature
remains above the saturated suction temperature plus
5.5°C (10°F) for 600 seconds, the clog timer will count
to “0” and the system will shut down and lock out. The
status fault will indicate an eductor clog fault.
SYS X FAULT: EDUCTOR CLOG FAULT
Whenever this fault occurs, the eductor filter should be
changed.
The clog timer resets to 600 seconds whenever the control
algorithm sees the eductor line temperature is less than
the saturated suction pressure plus 5.5°C (10°F). This
prevents nuisance eductor clog faults.