York YVAA Installation Operation & Maintenance page 140

Air-cooled screw liquid chillers, air-cooled screw liquid chillers with variable speed drive
Table of Contents

Advertisement

SECTION 8 - MICROPANEL
Low ambient cutout
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
LOW AMBIENT TEMP CUTOUT
The low ambient temp cutout allows programming the
outdoor temperature at which it is preferred to shut
down the chiller to use other methods of cooling.
The cutout is programmable between -18.9°C (-2.0°F)
and 10.0°C (50°F) with a -3.9°C (25°F) default.
Low leaving liquid temp cutout
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
LEAVING LIQUID TEMP CUTOUT = XXX.X °F
The leaving chilled liquid temp cutout is programmed
to avoid freezing the evaporator due to excessively low
chilled liquid temperatures. The cutout is automatically
set at 2.2 °C (36°F) in the Water Cooling mode and is
programmable in the Glycol Cooling mode. In the Gly-
col Cooling Mode, the cutout is programmable from
-11.7°C to 2.2°C (11.0°F to 36.0°F) with a default of
2.2°C (36.0°F).
Motor current limit
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
MOTOR CURRENT LIMIT
The motor current limit %FLA is programmable. This
allows the microprocessor to limit a system before it
faults on high current. The limit point is set at 100%.
The unload point is programmable from 30% to 100%
with a default of 100%.
Pulldown current limit
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
PULLDOWN CURRENT LIMIT
The pulldown current limit %FLA is programmable.
This allows the microprocessor to limit a system on
pulldown limiting for the purpose of peak time energy
savings. The limit point is set at 100%. The pulldown
limit point is programmable from 30% to 100% with a
default of 100%. Be aware when using pulldown mo-
tor current limit, the chiller may not be able to load to
satisfy temperature demand.
Pulldown current limit time
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
PULLDOWN CURRENT LIMIT TIME
The pulldown current limit time is programmable.
This allows the microprocessor to limit a system on
pulldown limiting for a defined period of time for the
140
= XXX.X °F
= XXX % FLA
= XXX % FLA
= XXX MIN
purpose of peak time energy savings. The pulldown
limit point is programmable from 0 to 255 with a
default of 0 Min.
Subcooling setpoint
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
SUBCOOLING SETPOINT
The liquid subcooling superheat setpoint is program-
mable from 0.0 to 11.1°C (0.0 to 20.0°F) with a 2.8°C
(5.0°F) default. The subcooling control is programmed
for 2.8°C (5.0°F).
Unit ID number
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
REMOTE UNIT ID NUMBER = X
For purposes of remote communications, multiple
chillers may be connected to an RS-485 communica-
tions bus. To allow communications to each chiller, a
chiller ID number may be programmed into memory.
On a single chiller application, the value will be "0".
Sound limit setpoint
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
SOUND LIMIT SETPOINT
The sound limit setpoint is programmable from 0% to
100 % with a 0% default. 0% allows operating up to the
full speed capability of the unit with no sound limiting.
The sound limit control setting is programmed for 0%
unless sound limiting is utilized on the chiller. Sound
limiting will only permit the unit to run to a frequency
less than the maximum speed capability of the unit.
Programming a value of 1% would be the minimum
sound limiting that can be programmed and 100% will
be the maximum. 100% only allows the unit speed to
operate at the minimum frequency. The sound limit %
is programmed somewhere between 0% and 100% ac-
cording to the limiting needed to satisfy the sound re-
quirements of the site. Sound limiting must be utilized
in areas sensitive to noise during night-time hours. The
sound limit display is only present if the sound limit
option is programmed at the factory.
Eductor differential
PROGRAM
◄DEF XXXXX LO XXXXX HI XXXXX
EDUCTOR DIFFERENTIAL
The eductor temperature differential is programmable
from 0°C to 10.0°C (0°F to 50.0°F). The default value
is 5.0°F.
Form 201.47-ICOM1
Issue date: 17/11/2022
= XXX.X °F
= XXX %
= XXX °F
JOHNSON CONTROLS

Hide quick links:

Advertisement

Table of Contents
loading

Table of Contents