Table of Contents
Advertisement
MICRO PANEL
On 3 compressor chillers, the baseplate temperatures on
compressors 1 and 3 are OR'd together and the high-
est of the two temperatures compared in software to a
limit of 232°F. Compressor #2 will have it's individual
power module sensor compared in software to a limit
of 232°F. If the limit is exceeded by either of the 2 in-
puts, the unit will fault and shut down with a controlled
ramped shutdown.
3 compressor chillers operate at higher
baseplate temperature compared to 2 or
4 compressor chillers.
On 4 compressor chillers, the baseplate temperatures on
compressors 1 and 3 are OR'd together and the highest
of the two temperatures compared in software to a limit
of 218°F. The baseplate temperatures on compressors
2 and 4 are OR'd together and the highest of the two
temperatures compared in software to a limit of 218°F.
If the limit is exceeded by either of the 2 inputs, the
unit will fault and shut down with a controlled ramped
shutdown.
This is an auto-restart safety that will lock out on the 3rd
fault in 90 minutes. The fault will be a system fault for
all units. Below are the Status display fault messages
for all systems.
SYS X YYYYYYYY HIGH VSD BASEPLATE TEMP
X indicates the system and YYYYYYY indicates the
system is in a "FAULT" condition and will restart when
the fault clears or "LOCKOUT" and will not restart until
the operator clears the fault using the keypad.
After a fault, the fan(s) and water pump will remain
energized until the inverter power module base plate
temperature(s) falls below 165°F. The system will be
allowed to restart when the inverter power module base
plate temperatures drop below this value.
It is possible for an internal sensor to fail and not sense
temperature without causing a high baseplate sensor
fault.
208
VSD SAFETIES (FAULTS) (CON'T)
High VSD Internal Ambient Temperature
(Software) Fault
The VSD Logic board contains a temperature sensor,
which monitors the unit's internal ambient temperature.
If the VSD internal ambient temperature rises above the
cutout of 158°F, the unit will fault and shut down with
a controlled ramped shutdown.
This safety will not cause a lockout. The fault will be a
unit fault for all units. Following is the Status display
fault message.
UNIT YYYYYYYY
HIGH VSD INTERNAL AMBIENT TEMP
The unit will be allowed to restart when the internal
ambient temperature drops 10°F below the cutout.
YYYYYYYY indicates the unit is in a "Fault" condition
and will restart when the condition clears.
Single Phase Input (Hardware) Fault
The VSD's SCR Trigger Control board contains circuitry
that checks the three phase mains for the presence of
all three-line voltages. If any of the line voltages are
not present, the system will immediately shut down on
a fault.
This fault will not cause a lockout. The fault will be
a unit fault for 2 or 3 compressor units. Below is the
Status display fault message.
UNIT YYYYYYYY
SINGLE PHASE INPUT VOLTAGE
The fault will be a system fault 1/3 or 2/4 for 4 com-
pressor units. Two key presses of the STATUS key are
required to show the fault on both systems. Below is
the fault message for all systems.
SYS X YYYYYYYY SINGLE PHASE INPUT VOLTS
X indicates the system and YYYYYYY indicates the
system is "FAULT" and will restart when the single
phase condition clears.
FORM 201.21-NM1 (1223)
JOHNSON CONTROLS
Advertisement
Table of Contents
