Quantech QWC4, Installation Operation & Maintenance, Page: 100 / 156

QUANTECH
100
FORM QWC4-NM1 (221)
ISSUE DATE: 02/28/2021
SECTION 6 - OPERATION
MESSAGE DESCRIPTION
YYYYYYY HIGH
DISCHARGE
PRESSURE
Software-Initiated Fault - A system will fault and shut down with a ramped shutdown when the
high discharge pressure rises above 333 psig (2300 kPa) for 0.5 seconds. The system will be
allowed to restart when the discharge pressure falls to 293 psig (20.2 kPa). The system will also
be inhibited from starting if the pressure is above 293 psig (2020 kPa). YYYYYYYY will show
FAULT to indicate a system is in a FAULT condition, will restart when the condition clears, and
the 120-second anti-recycle timer times out. If three faults occur within 90 minutes, LOCKOUT will
appear, and will not restart until the operator clears the fault using the keypad.
YYYYYYY HIGH
DISCHARGE TEMP
This fault protects the motor and compressor from overheating. A system will fault and shut down
with a ramped shutdown when its discharge temperature rises above 225°F (107°C). A system
will be inhibited from starting, if the discharge temperature is above 175°F (79°C). YYYYYYYY
will show FAULT to indicate a system is in a FAULT condition, will restart when the condition
clears, and the 120-second anti-recycle timer times out; or YYYYYY will show LOCKOUT, and the
system will not restart until the operator clears the fault using the keypad.
YYYYYYY HIGH
MOTOR CURRENT
Hardware-Initiated Fault - The three output lines to the compressor motor are monitored via
three current transformers within the drive. The unit’s three phases of instantaneous output
current are compared to a prescribed limit, contained in hardware. The nominal peak current
trip level is dependent on the configuration of the VSD as follows: 460 V 60 Hz, VSD Frames, A
and B shutdown is 575.5 amps (554 amps (min.) 597 amps (max)), 380 V 50/60 Hz and 400/415
V 50 Hz, VSD Frames A and B shutdown is 649.5 amps (626 amps (min.), 674 amps (max)),
and 380V 50/60 Hz and 400/415 V 50 Hz, VSD Frames C and D, and 460V 60 Hz Frame D
shutdown is 863.3 amps (831 amps (min.), 896 amps (max)). This auto-restart safety will lock
out on the third fault in 90 minutes. The VSD shutdown type is immediate. YYYYYYY will show
FAULT to indicate a system is in a FAULT condition, and will restart when the 120 second anti-
recycle timer times out; or will show LOCKOUT, and the system will not restart until the operator
clears the fault using the keypad.
YYYYYYY HIGH
MOTOR TEMP Z
This fault prevents a compressor from running when its motor temperature is too high. A system
will shut down when any of its two or three compressor motor temperature sensors rises above
250°F (115 °C). The system will be inhibited from starting if any of its motor temperature sensors
is above 240°F (120°C). This fault causes a lockout on the third fault in 90 minutes. If any motor
temperature sensor is being ignored (as selectable under UNIT SETUP MODE) that sensor will
not be used in evaluating the high motor temperature safety and start inhibit. YYYYYYY will show
FAULT to indicate a system is in a FAULT condition, and will restart when the 120 second anti-
recycle timer times out; or will show LOCKOUT, and the system will not restart until the operator
clears the fault using the keypad. Z is the MOTOR TEMP SENSOR NO.
YYYYYYY HIGH VSD
BASEPLATE TEMP
Software-Initiated Fault - The VSD phase bank assembly contain one heat sink to cool both
the inverter power modules and the converter SCR/Diode modules. Each module contains an
internal temperature sensor (5K ohm at 0°F (25°C)) to monitor its baseplate temperature. The
inverter power module’s baseplate temperatures on the Compressor is compared in software to
a limit dependent on the VSD configuration as follows. When the limit is exceeded the unit is shut
down: 218°F (103.3°C) for Frames A and B, and 226°F (103.3°C) for Frames C and D. This auto-
restart safety will lock out on the third fault in 90 minutes. The VSD shutdown type is ramped.
TABLE 33 - SYSTEM SAFETIES FAULTS (CONT'D)