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FORM 160.54-M1
ISSUE DATE: 10/25/2019
SI0271 - SOFTWARE ENHANCEMENTS (VER 25) EFFECTIVE AUGUST 2013 (CONT'D)
On startup the Shutdown Temperature is set to the cal-
culated value.
On a LCLT Setpoint increase or Shutdown Tempera-
ture Offset increase, the Shutdown Temperature is in-
creased immediately.
On a LCLT Setpoint decrease or Shutdown Tempera-
ture Offset decrease, the Shutdown Temperature is de-
creased at 0.05 °F/sec.
Maximum Limit for LCHLT Setpoint
The maximum limit for the local and remote LCHLT
setpoint was changed from 70.0°F to 72.0°F.
Warning – DC Bus Active
A non-annunciating warning has been added to alert
the user that the MVVSD, VSD or Harmonic Filter DC
bus voltage is above 50 VDC posing a potential safety
issue if the cabinet is opened. This warning is active
when the chiller is in the Stopped State and is automat-
ically cleared in any other state. The warning message
reads "Warning – VSD – DC Bus Active" in yellow
text. The Warning Relay is not activated for this warn-
ing. This warning only applies when the Motor Drive
Type is VSD 50Hz, VSD 60Hz, or MVVSD. VSD 50
and 60Hz includes Vyper and Raptyr designed drives.
Stall Voltage Precision
The precision of the Stall Voltage and programmable
High Limit and Low Limit has been changed from
tenths to hundredths. The programmable limits have
been changed as follows:
PROGRAM
SCREEN
MODE
SETTING
VGD
Service
High Limit
Setpoints
Access
VGD
Service
Low Limit
Setpoints
Access
Auto VSD Speed Control at Wide Open Vanes
The, ACC control did not allow the VSD speed to be
increased to control capacity until the PRV position
was greater than or equal to 98% PRV position. Once
above 98% PRV, VSD speed increases were allowed
until the PRV position fell below 95%. This has been
changed to allow speed increases when the PRV posi-
JOHNSON CONTROLS
DE-
MIN.
MAX.
FAULT
1.20
0.35 V
0.60 V
V
0.80
0.30 V
0.50 V
V
JCI COMPANY CONFIDENTIAL
SECTION 36 - SOFTWARE ENHANCEMENTS
tion is above 95% and released when the PRV position
falls below 93%. This change was needed because of
inconsistent PRV readings or the PRV's being out of
calibration.
Subcooler Tube Failure
Liquid Level Setpoint Not Achieved Warning
An Automatic Reset Warning has been added that dis-
plays the message "Warning – Liquid Level Setpoint
not Achieved". This warning is set when all of the fol-
lowing are true for 10 continuous minutes:
• Chiller is Running
• Run Time > 30 minutes
• Refrigerant Level > (Refrigerant Level setpoint
+15%) OR Refrigerant Level < (Refrigerant Lev-
el setpoint -15%)
It is released when:
• Chiller is not Running
• (Refrigerant Level setpoint -15%) < Refrigerant
Level < (Refrigerant Level setpoint +15%)
When this warning occurs, it shall be added to the se-
curity log.
Refrigerant Level Control Modifications
Refrigerant level control should not be set to Disable
on variable orifice chillers. To correct the misuse of the
feature, operation of the outputwas changed as follows:
If the Refrigerant level control is disabled:
• Refrigerant Level Lower (open) output is de-en-
ergized
• Refrigerant Level Raise (close) output is ener-
gized
Loss of Subcooler Liquid Seal Warning
If the chiller has been running for 30 minutes or more
and the Drop Leg Temperature is less than the Return
Condenser Liquid Temperature continuously for two
minutes, the following warning message is displayed:
"Warning - Loss of Subcooler Liquid Seal"
36
375
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