York YR Manual page 93

FORM 160.81-O1 (1020)
ISSUE DATE 10/05/2020
CONTROL PANEL – POWER FAILURE
A Control Power failure has occurred. The chiller can
be started after the COMPRESSOR switch is placed in
the Stop-Reset (O) position. This message can indicate
a Cycling (auto-restart after power failure) or Safety
(manual restart after power failure) shutdown, depend-
ing upon Control Center configuration. It indicates a
cycling shutdown when displayed in orange characters;
safety shutdown when displayed in red characters. The
Control center is configured for auto-restart or man-
ual restart after power failure by a qualified Service
Technician following instructions in OptiView Control
Center Service Instructions (Form 160.81-M1).
MOTOR OR STARTER – CURRENT IMBALANCE
The three-phase compressor motor current imbalance
was more than 30% continuously for 45 seconds. The
imbalance is not checked until the chiller has been run-
ning for at least 45 seconds and the average of the three
phases of motor current is more than 80% of the pro-
grammed 100% chiller Full Load Amps.
The average is calculated as: Iave = (Ia+Ib+Ic) ÷ 3.
The imbalance is calculated as:
(Ia-Iave) + (Ib-Iave) + (Ic-Iave)
2(Iave)
The Style B Solid State Starter detects the unbalance
condition and advises the OptiView™ Control Center
Microboard via serial communications. This safety
shutdown is not performed on Electro-Mechanical
Starter applications.
WATCHDOG – SOFTWARE REBOOT
The Microboard's software watchdog initiated a mi-
croprocessor reset because it detected that a portion of
the chiller operating program was not being executed.
The result of this reset is a safety shutdown and re-ini-
tialization of the Program. This is generally indicative
of a severe electrical power disturbance or impending
Microboard failure. The chiller can be started after the
COMPRESSOR switch is placed in the Stop-Reset (O)
position.
MOTOR – PHASE ROTATION
The Discharge Pressure did not increase by at least 0.5
PSIG during the first 5 seconds after the motor was
started, or did not further increase by another 0.5 PSIG
over the next 10 seconds.
JOHNSON CONTROLS
This is indicative of incorrect compressor rotation. If
compressor rotation is correct, the Discharge Pressure
will increase when the compressor is started. The AC
power line connections to the starter or compressor mo-
tor should be corrected to provide correct rotation. The
chiller can be started after the COMPRESSOR switch
is placed in the Stop-Reset (O) position.
MOTOR – HIGH MOTOR TEMPERATURE
The Motor Thermal Protection device (MTP) contacts
connected to I/O Board TB3-70 have opened due to
a high motor temperature condition. The chiller can be
started after the contacts have closed and the COMPRES-
SOR switch is placed in the Stop-Reset (O) position.
MOTOR – GROUND FAULT
(Style B and later chillers with software version
C.MLM.05.04.xxx (and later)) The Motor Ground
Fault detector, located in the Solid State Starter, has
detected a Ground Fault. A current transformer output
energizes a relay for the duration of the Ground Fault
event. The relay normally open contacts close to apply
115VAC to I/O Board TB3-71. With software version
C.MLM.05.06.xxx (and later) or C.OPT.05.06.xxx
(and later), an ADMIN password is required to clear
this fault and restart the chiller. This is to prevent the se-
x 100
vere compressor/motor damage that could occur from
initiating chiller starts after this fault has occurred. To
prevent restarting the chiller until the motor condition
can be evaluated, the chiller cannot be started until the
Ground Fault contacts (TB3-71) open and a qualified
service technician obtains an ADMIN password from
YORK and performs a special reset procedure listed in
OptiView Control Center Service Instructions (Form
160.81-M1). With all previous software versions, the
chiller can be restarted after the Ground Fault contacts
open and the COMPRESSOR switch is placed in the
Stop-Reset (O) position.
105% MOTOR CURRENT OVERLOAD
(Software version C.OPT.05.07.xxx (and later).
The compressor motor current has exceeded 105% of
the Chiller Full Load Amps continuously for a time
period exceeding the setting of the 105% Motor Cur-
rent Time setpoint (12 to 40 seconds). The chiller can
be started after the COMPRESSOR switch is placed in
the Stop-Reset (O) position.
SECTION 3 - DISPLAY MESSAGES
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