Table 3 - Current Limit Thresholds - Johnson Controls YORK OPTIVIEW CONTROL CENTER Operation Manual

SECTION 3 - OPTIVIEW DISPLAY MESSAGES
System Stopped
This message indicates the chiller has been command-
ed to stop, locally or by remote, the System Coastdown
is complete, and the chiller control switch is in the
RUN position. Once the control switch is moved to the
OFF position and there is nothing preventing safe op-
eration of the chiller, the message will revert to SYS-
TEM READY TO START.
SYSTEM RUN MESSAGES
LEAVING CHILLED LIQUID CONTROL
The chiller is running and controlling the chilled liquid
to the Leaving Chilled Liquid Temperature Setpoint.
There are no system conditions inhibiting this operation.
Motor – High Current Limit
The compressor motor current is greater than or equal to
the Local or Remote Current Limit Setpoint. When the
motor current increases to the INHIBIT OPEN thresh-
old, the pre-rotation vanes are inhibited from opening,
preventing any further increase in motor current. If the
current continues to rise to the START CLOSE thresh-
old, the vanes begin closing until the current falls to
the STOP CLOSE threshold. Auto vane operation is
resumed and this message automatically clears when
the motor current decreases to the ALLOW OPEN
threshold. The thresholds are different for the various
motor starter applications. To allow field calibration
of the CM-2 current module, pressing the pre-rotation
vanes OPEN key in SERVICE access level, starts a 10
minute timer during which the current limit thresholds
are elevated. Refer to Table 3 below:

TABLE 3 - CURRENT LIMIT THRESHOLDS

VANE
CONTROL
State Starter
On rise, inhibit open
On fall, allow open
On rise, start close
On fall, stop close
An example of current limit is as follows: If a chiller
with an electromechanical starter FLA is 100 Amps,
and the current limit setpoint is 50%, the following will
occur:
50 Amps: Inhibit Vane Open
52 Amps: Vanes Begin Closing
102
MOTOR CURRENT (% FLA)
E-M/Solid Service
VSD
Mode
100 100 107
98 93 106
104 103 110
102 101 109
51 Amps: Vanes Stop Closing
49 Amps Allow Automatic Vane Control
Current Pulldown Limit
The PULLDOWN DEMAND LIMIT SETPOINT
timer is in effect and the compressor motor current is
greater than or equal to the pulldown demand current
limit setpoint value. The pre-rotation vane operation is
being inhibited as described under MOTOR – HIGH
CURRENT LIMIT.
START INHIBIT MESSAGES
Anti-Recycle XXmin/Sec
The chiller is inhibited from starting because the thirty
(30) minute anti-recycle time has not yet elapsed. Time
remaining is displayed.
Vane Motor Switch Open
The chiller is inhibited from starting because the pre-
rotation vanes are not fully closed.
Motor Current >15% FLA
The OptiView Control Center has detected a com-
pressor motor current that is greater than 15% of the
chiller full load amps for ten (10) continuous seconds,
while the chiller is stopped. As long as this condition
exists, the oil pump is turned on. This message is gen-
erally indicative of motor starter, control center start
circuits, or motor current feedback circuits failure.
After motor current is no longer detected, a SYSTEM
COASTDOWN is performed. The chiller can be start-
ed after motor current is no longer detected, the system
coastdown has completed and the compressor switch is
placed in the STOP/RESET (O) position.
LCSSS – High Temperature Phase X –
Stopped
The chiller is stopped and the liquid cooled solid state
starter logic/trigger board has detected that the temper-
ature of the phase A, B, or C (designated as X in this
message) Silicon Controlled Rectifier (SCR) module is
above 110°F. The starter cooling pump will run and the
chiller will be inhibited from starting until the tempera-
ture decreases below 109°F.
WARNING MESSAGES
Warning – Real Time Clock Failure
During the initialization process that occurs when
power is applied to the control center, test data is writ-
FORM 160.10-O1
ISSUE DATE: 4/27/2018
JOHNSON CONTROLS