JOHNSON CONTROLS
82
FORM 160.69-O1
ISSUE DATE: 9/30/2012
SECTION 2 – OPTIVIEW CONTROL CENTER
Chiller Current is limited to 1120 amps. If only one
motor is running, the Motor Current Limit (see Motor
Current Limit Setpoint above) for that motor would be
set to 100% and it would be allowed to operate at its
maximum of 800 amps, However, if both motors are
running, each would be limited to 560 amps per motor,
producing a Chiller Current of 1120 amps.
Lead Compressor Pulldown Time
(Software Version C.OPT.11.03.01.004 (and later))
Access Level Required:
OPERATOR
This setpoint is used to limit the chiller to single com-
pressor operation for a specified duration (0-255 min-
utes) when starting the chiller. While this pulldown
time is in effect, “System in Lead Compressor Pull-
down” is displayed on the system details line along
with the time remaining in the period. During this
time, only the lead compressor is permitted to run. The
lag compressor will not be brought on line. After this
time has elapsed, the lag compressor can be brought
on line per normal operation. While this period is in ef-
fect, the lead compressor motor current will be limited
to the value programmed for the
Lead Compressor
Pulldown Demand Limit
Setpoint (30-100% FLA).
The CHILLER PULLDOWN DEMAND LIMIT
Setpoint (that was used during the CHILLER PULL-
DOWN PERIOD in previous software versions, see
above) has been removed in this and later software
versions. Although this setpoint has been removed, the
logic in the CHILLER PULLDOWN PERIOD that is
used to determine if it is necessary to bring on the Lag
compressor (to meet load) still exists. This period is
still in effect from start until the Leaving Chilled Liq-
uid Temperature is within 2ºF of the Leaving Chilled
Liquid Temperature Setpoint. However, the “Chiller
Pulldown In Effect” LED (that indicated when the
Chiller Pulldown Period is in effect) has been elimi-
nated from the MOTOR Screen to avoid confusion
with the Lead Compressor Pulldown Demand Limit
feature.
After the Lead Compressor Pulldown Time Setpoint
has elapsed, the chiller current limit will be limited to
the value programmed for the
Chiller Current Limit
Setpoint. As in previous software versions, this setpoint
is applied to the total chiller current (30% to 100% of
the Chiller Full Load Amps). For example, if the Chill-
er FLA is 1600 Amps, the FLA of each motor is 800
Amps. If this setpoint is set to 70%, the Chiller Cur-
rent would be limited to 1120 Amps. If both compres-
sors are running, each would be limited to 560 amps. If
only one motor is running, the motor would be allowed
to operate all the way up to its full load amps of 800
Amps, because the total chiller current is being limited
to 1120 Amps.
Lead Compressor Pulldown Demand Limit
(Software Version C.OPT.11.03.01.004 (and later))
Access Level Required:
OPERATOR
Allows the user to specify a motor current limit (30%
to 100% FLA) that’s applied to the Lead compres-
sor motor during the time period programmed as the
LEAD COMPRESSOR PULLDOWN TIME Setpoint
(see above). This current limit applies to the full load
amps of the Lead compressor motor only, not the Chill-
er Full Load Amps (total of both compressors). For ex-
ample, if the Chiller Full Load Amps is 2000A, then
each compressor’s FLA is 1000A. If set to 80%, then
the lead compressor motor current would be limited to
800A (80% x 1000) for the duration of this period.
Navigation
Home
Access Level Required:
VIEW
Causes a return to the Home Screen.
Motor Lube Screen
(Software version C.MLM.11.02.xxx (and later) or
C.OPT.11.02.300 (and later)).
Access Level Required:
VIEW
Moves to the sub-screen allowing operator acknowl-
edgement of the compressor motor lubrication and
viewing of the compressor motor lubrication param-
eters.