| Document type | Service Information Letter |
|---|---|
| Document number | SI0541 |
| Equipment | YCAV Variable Speed Drive Screw Chiller |
| Brand | YORK |
| File size | 0.3 MB |
Fault codes in this document
SYSTEM FAULTS
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| Low Suction Superheat Fault | The Low Suction Superheat Cutout is to protect the compressor from liquid flood back due to low suction superheat. | After the first 30 seconds (60 seconds if Soft Shutdown is Enabled) of run time, if the suction superheat < 2°F and the discharge superheat < 15°F and the run time < 5 minutes, ignore the cutout for 30 seconds (60 seconds if Soft Shutdown is Enabled) and then ramp the cutout from 0°F to 2°F over the next 60 seconds (90 seconds if Soft Shutdown is Enabled). If the suction superheat falls below the ramped cutout, the system will trip. If the suction superheat < Suction Superheat Setpoint – 3°F (max of 5°F) for 10 minutes, the system will trip. |
System will trip. This safety is ignored for the first 60 seconds (120 seconds if Soft Shutdown is Enabled) of system run time unless a restart transition has occurred. If a restart transition has occurred, the timer is set according to the following table with a maximum limit of 73 seconds: If current freq > 100 Hz: Increase timer by [(current freq – 100Hz) / 30.4 Hz/sec] + 9.5 sec If current freq <= 100 Hz: Increase timer by [(current freq – 5Hz) / 10 Hz/sec] Always: Increase timer by 60 seconds (NOTE: 9.5 sec = [(100Hz – 5Hz) / 10 Hz/sec], the time it takes to ramp from 100 Hz to 5 Hz.) Low Suction Superheat fault is ignored when any of the following are true: Soft Shutdown is in process; Ramp down while the other system is performing soft shutdown is in process; 90 seconds after ramp up starts due to ramp down / up while the other system was performing a soft shutdown. |
2 |
Compressor Shutdown Control
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| Low Ambient Temp | The Low Ambient Temp fault is changed to perform a soft ramped shutdown if soft shutdown is enabled. | Shutdown Type: Ramped when Soft Shutdown is Disabled; Soft Ramped when Soft Shutdown is Enabled. | 4 |
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