York YK-EP Operation And Maintenance Manual page 193

Warning – Evaporator – Low Pressure Limit
The Evaporator Pressure has decreased to the Warning threshold. This threshold is fixed in Water
cooling applications. In Brine cooling applications, the threshold is a fixed amount above the
programmable safety shutdown threshold. The Safety threshold in Brine applications is determined
by the Brine solution and is determined by the YORK Factory. While this condition is in effect, the
Pre-Rotation Vanes are inhibited from further opening. This message automatically clears and the
Vanes are permitted to open when the Evaporator Pressure increases to the reset value.
Table 198: Warning and reset thresholds
Warning threshold (PSIG)
Water
R22 56.2
R134a 27.0
Warning – Vanes Uncalibrated – Fixed Speed
The Compressor Motor Variable Speed Drive (VSD) is operating Fixed Speed (full speed) mode
because the Pre-Rotation Vanes position potentiometer calibration has not been performed.
Warning – Harmonic Filter – Operation Inhibited
The Compressor Motor Variable Speed Drive (VSD) Harmonic Filter has been inhibited. Refer to
Variable Speed Drive – Service Instructions (Form 160.00-M1). Harmonic Filter operation should not be
altered by anyone other than a qualified Service Technician.
Warning – Harmonic Filter – Data Loss
Communications between the Harmonic Filter Logic Board and the Compressor Motor Variable
Speed Drive VSD Logic Board or the Adaptive Capacity Control Board is not occurring. While this
condition exists, all filter related parameters are displayed as X's. This message automatically clears
when communications are restored.
Warning – Harmonic Filter – Input Frequency Range
The power line frequency detected by the Compressor Motor Variable Speed Drive (VSD) Harmonic
Filter is outside the range of 58 to 62 Hz (60 Hz), or 49 to 51 Hz (50 Hz). While this condition exists,
all filter related parameters are displayed as X's. This message automatically clears when the line
frequency is within range.
Warning – Harmonic Filter – Not Running
This warning is set when all of the following are true for 20 continuous seconds:
• Chiller is running
• Filter is enabled
• Filter present status is true
• Run Time greater than 20 seconds
• Filter operating mode is stopped
This warning is released when the chiller is stopped, but will be displayed until manually cleared
using the WARNING RESET key when logged in at OPERATOR (or higher) access level.
Warning – Vanes Uncalibrated
The Hot Gas Bypass feature is enabled, but the Pre-Rotation Vanes calibration procedure has not
yet been performed.
YK-EP Style B Centrifugal Chiller
Brine
+1.9 more than Safety Setpoint
+2.0 >Safety Setpoint
Reset threshold (PSIG)
Water
57.5 +3.2 more than Safety Setpoint
28.0 +3.0>Safety Setpoint
Brine
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