JOHNSON CONTROLS
103
SECTION 6 - OPERATION
FORM 201.30-ICOM1 (519)
ISSUE DATE: 05/22/2019
6
MESSAGE
DESCRIPTION
YYYYYYY LOW EVAP
PRES SMART FREEZE
This fault is considered active when SMART FREEZE is turned on via the enable/disable setting,
and the active LCHLT control setpoint is less than or equal to 38.0°F (3.3°C). SMART FREEZE
can only be enabled or disabled while the chiller is stopped, and is only available in water
applications. It is a lockout fault on the first occurrence. While Smart Freeze Point Protection is
enabled, a timer starts incrementing when any system evaporator saturation temperature is less
than 32.8°F (0.44°C) and decrementing when all system evaporator saturation temperatures
are greater than 32.8°F (0.44°C). The timer is reset to zero when Smart Freeze is inactive. The
system will be able to start after the evaporator temperature is greater than freeze threshold
or the timer is less than the calculated time to freezing. The number of seconds it will take the
water in the evaporator tubes to freeze is calculated from the system evaporator saturation
temperature and the freeze threshold of 32.8°F (0.44°C) as follows:
Time (seconds) to freezing = (4053.7)/(freeze threshold – lowest system
evaporator saturation temperature)
If the lowest system evaporator saturation temperature is 26.0 °F, water in the evaporator would
freeze in nine minutes and 56 seconds. YYYYYY will show LOCKOUT, and the system will not
restart until the operator clears the fault using the keypad.
YYYYYYY LOW OIL
LEVEL
This fault is only active when the oil level switch control is enabled under the PROGRAM key
with a service password. It senses when voltage is removed from control board input J5-1. These
inputs are designated for future use for proposed oil level switches that are currently not included
in this design. This fault prevents the system from starting. YYYYYYY will show LOCKOUT, and
the system will not restart until the operator clears the fault using the keypad.
YYYYYYY MOTOR
CURRENT OVERLOAD
Software-Initiated Fault -
This fault compares the highest of the three phases of motor current
per compressor to the compressor’s 105% FLA ADJUST (overload) potentiometer setting. If
the current exceeds the setting continuously for 20 seconds, the compressor will shut down.
This safety will lockout a system on the first occurrence. The VSD shutdown type is immediate.
YYYYYYY will show LOCKOUT, and the system will not restart until the operator clears the fault
using the keypad.
YYYYYYY SENSOR
FAIL: ZZZZZZZZZZZZZ
This fault prevents the system/unit from running when critical sensors are not functioning
properly or are reading out of range. This safety is reviewed on start-up and the system or unit
will be inhibited from starting, if one of the sensors inputs is out of range. This fault will shutdown
the unit if any of the sensor inputs goes out of range. Ranges are: evaporator, condenser, oil,
discharge and economizer pressure transducer: < 0.3V or > 4.7V, level sensor: < 3.0mA or >
21mA, eductor temperature sensor: < 0.86V (~ -5°F) or > 4.67V (~ 161°F), Motor temperature
sensors reads greater than 1015 AD counts, which will prevent the unit from starting or running
if a motor temp sensor is unplugged or has failed to open. If any motor temperature sensor is
being ignored (under UNIT SETUP MODE) that sensor will not be used in evaluating this safety.
The display will indicate which sensor failed in the ZZZZZZZ field as follows: EVAP PRESS, OIL
PRESS, COND PRESS, DISCH PRESS, ECONO PRESS, COND LEVEL, and MOTOR TEMP.
Z is the MOTOR TEMP SENSOR NO.
YYYYYYY VSD RUN
RELAY
Software-Initiated Fault -
The control sends the VSD logic board a start command over
communications and over hardwire run. Upon receipt of the two types of run commands
(hardwire or communications) a five second timer starts timing. The other run signal must
be asserted within the five second window or the system will shut down. If either run signal
is disabled while the VSD is running, the remaining run signal must be disabled within five
seconds after the VSD has shut down or the system will shut down. This is an auto-restart
safety that will lock out on the third fault in 90 minutes. YYYYYYY will show FAULT to indicate 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.
TABLE 33 -
SYSTEM SAFETIES FAULTS (CONT'D)
Summary of Contents for YVWA
Page 155: ...JOHNSON CONTROLS 155 NOTES...
