Johnson Controls YORK YVAM 0350, Operation & Maintenance Manual

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Table 92: Safety shutdown messages
Message Description
VSD – INPUT
CURRENT OVERLOAD
The input current overload value is variable based on the Input Job Full Load Amps value
programmed at the Control Panel. The input current overload value is 1.16 times the Input Job Full
Load Amps value, but not to exceed the value for the given model of drive listed in the following
table.
Drive model Input current maximum overload
0490B 511 A
This calculation takes into account installations where the input line voltage could be up to 10% below
the nominal value. An additional 5% of current is added to reduce nuisance shutdowns due to power
fluctuations. To provide additional time for the chiller to unload, the input current overload value
must be greater than the shutdown value for 10 continuous seconds for this shutdown to occur.
When the condition clears, the chiller can be started after the Clear Faults button is pressed.
VSD – INPUT DCCT
OFFSET LOCKOUT
If three consecutive VSD – Phase A, B, or C Input DCCT Offset cycling faults occur, this safety
shutdown is generated to require investigation and manual reset. When the condition clears the
chiller can be started after the Clear Faults button is pressed.
VSD – INVERTER
PROGRAM FAULT
The drive software contains a verification process to ensure that the correct set of software is
installed in the drive logic board for the application. When this condition clears, the chiller can be
started after the Clear Faults button is pressed.
VSD – LOGIC BOARD
HARDWARE
After power is applied to the chiller, the drive logic board performs several internal tests to ensure
proper operation of the input power device. If the tests fail, then this shutdown is generated. When
this condition clears, the chiller can be started after the Clear Faults button is pressed.
VSD – LOGIC BOARD
PLUG
A jumper is located in the rectifier and inverter current transformers connectors that indicate the
connector is correctly installed. If either connector is not installed, then this shutdown is generated.
When the condition clears, the chiller can be started after the Clear Faults button is pressed.
VSD – MOTOR
CURRENT IMBALANCE
Each phase of motor current is compared against the average of the three phases of motor current
to determine the current imbalance value. If the current imbalance value is greater than 32 A for a
period of 45 seconds, then this shutdown is generated. For example: The three motor current RMS
values are 200 A, 225 A, and 240 A. This is calculated to an average current of
(200 + 260 + 240)/3
= 233 A . Subtract the real current value from the average value: 200 – 233 = 33 , 260 – 233 =
33
,
240 – 233 = 7
. If this condition or worse were maintained for 45 seconds, then this shutdown
is generated, because the motor current imbalance is 33 A. The chiller can be started after the Clear
Faults button is pressed.
VSD – 105% MOTOR
CURRENT OVERLOAD
The 105% motor current overload value is based on the highest output current compared to the
programmed Motor Current value displayed on the control panel.
Drive model Maximum motor current overload shutdown value
0490B 490 A
The 105% motor current overload value is 1.05 times the programmed Motor Current value displayed
on the Control panel. The motor current overload value must be greater than the shutdown value
for 40 continuous seconds for this shutdown to occur. Higher values of output current can cause the
overload fault to occur sooner. For example, at 110% of motor current overload, the drive will fault
in 20 seconds. Also, if 114% of motor current overload, the drive will fault in approximately 1 second.
When the condition clears, the chiller can be started after the Clear Faults button is pressed.
VSD – MOTOR
CURRENT THD FAULT
This shutdown provides protection to the compressor motor. High levels of motor current total
harmonic distortion (THD) can cause the motor to overheat. Verify that all wiring is correctly
connected between the inverter and the output harmonic filter. When the condition clears, the chiller
can be started after the Clear Faults button is pressed.
VSD – PHASE A
INPUT DCCT
The input current in each phase to the drive is measured during the precharge time. If the input
current does not exceed the shutdown value for the given model of drive listed in the following table,
then this shutdown is generated.
Drive model Minimum input current shutdown value
0490B 5.0 A
When the condition clears, the chiller can be started after the Clear Faults button is pressed.
109 YVAM Control Center