Specifications

57
JOHNSON CONTROLS
Form 201.28-NM1.EN.PED/CE (0211)
7
High VSD Internal Ambient Temperature (Soft-
ware) 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 70°C (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. Following is the Status display fault message.
UNIT FAULT:
HIGH VSD INTERNAL AMBIENT TEMP
The unit will be allowed to restart when the internal
ambient temperature drops 5.6°C (10°F) below the
cutout.
FAULT 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. Below is the Status display fault message.
UNIT FAULT:
SINGLE PHASE INPUT VOLTAGE
FAULT indicates the system is “FAULT” and will restart
when the single phase condition clears.
Power Supply (Hardware) Fault
Various DC power supplies which power the VSD Logic
Board are monitored via hardware located on the logic
board. If any of these power supplies fall outside their
allowable limits, the unit will immediately shut down on
a fault.
This is an auto-restart safety that will restart after the
fault clears and lock out on the 3rd fault in 90 minutes.
The fault will be a unit fault. Below is the Status display
fault message.
UNIT FAULT:
VSD LOGIC BOARD POWER SUPPLY
FAULT 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.
Run Relay (Software) Fault
Upon receipt of either of the two types of run commands
(hardware and software) a 5 second timer will commence
timing. The hardware run signal comes from the SYS X
VSD Run Signal to the VSD Logic Board. The software
run signal comes through the comms from the Chiller
Control Board. If the missing run signal is not asserted
within the 5 second window, the system will fault. In
addition, if either run signal is disabled while the VSD is
running, the remaining run signal must be disabled within
5 seconds after the VSD is shut down or the system will
fault. If running, the unit will fault and shut down with a
controlled ramped shutdown.
This is an auto-restart safety that will autostart after the
120 second anti-recycle timer times out and will lock out
on the 3rd fault in 90 minutes. The fault will be a system
fault.
SYS X FAULT: VSD RUN RELAY
X indicates the system and FAULT 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.
VSD Logic Board Failure (Software) Fault
Upon receipt of the voltage and frequency commands,
the PWM generator will acknowledge receipt of the
command. If the system microprocessor does not
receive the handshake within 1.5 seconds of issuing the
command, the unit will trip. This safety is only active
during precharge and during running of a compressor.
It is not active when all the compressors are shut down
and the precharge is disabled. If the VSD Logic Board
Fault occurs while the chiller is running, all systems will
immediately shut down on a fault.
This is an auto-restart safety that will auto restart after
the 120 second anti-recycle timer times out and lock out
on the 3rd fault in 90 minutes. The fault is a unit fault for
all units. Following is the fault message.
UNIT FAULT:
VSD LOGIC BOARD FAILURE