YORK YVAA — EDUCTOR CLOG FAULT

The status fault shows EDUCTOR CLOG FAULT; the control documentation also prints it as Eductor clog fault. It is one of the system safeties and appears when the eductor clog detection safety trips.

This safety senses a loss of oil return to the compressor. To do that, it 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 and compares it with the saturated suction temperature plus 5.5°C (10°F). A temperature that stays above that threshold means oil is no longer returning to the compressor through the eductor; when it remains above the threshold for 600 seconds, the clog timer counts to 0 and the system shuts down and locks out.

• The eductor line temperature stays greater than the saturated suction temperature plus 5.5°C (10°F): the clog timer is decremented one second for each second above the threshold, and if the temperature remains above it for 600 seconds the timer counts to 0. The timer resets to 600 seconds whenever the temperature is below the threshold, which prevents nuisance faults.
• The eductor valve was not opened: for units with optional eductor and suction valves, the manual warns that failure to open the eductor valve results in eductor clog faults.

1. Change the eductor filter — the manual states: Whenever this fault occurs, the eductor filter should be changed.
2. If optional eductor and suction valves are installed on the unit, confirm that the eductor valve is open, since leaving it closed results in eductor clog faults.

• Threshold: saturated suction temperature plus 5.5°C (10°F).
• Clog timer: set at 600 seconds at start; one second is decremented for each second the eductor line temperature is above the threshold.
• Timer reset: back to 600 seconds whenever the eductor line temperature is below the threshold.
• Sampling: the eductor line temperature is checked once a second.
• Eductor differential and eductor safety time are programmable under the PROGRAM key.

The system shuts down and locks out. As a lockout, the unit will not restart until the operator clears the fault using the keypad. Before restarting, change the eductor filter, which the manual requires after every occurrence of this fault.