192
JOHNSON CONTROLS
FORM 201.21-NM4 (616)
192
JOHNSON CONTROLS
OPERATION
SOUND LIMIT CONTROL
(LOCAL AND REMOTE RESET CONTROL)
Sound Limiting and Local Sound Limit
Setpoint
Sound limit control to reduce overall chiller noise levels
at specified times of the day is accomplished by setting
a Sound Limit Setpoint. There are several ways to set
the Sound Limit Setpoint. The first is by changing the
Local Sound Limit Setpoint under the PROGRAM key.
This is the value the unit will use for sound limiting, if
neither of the other methods is active. If any other sound
limit methods are active, the lowest value will be used.
A sound limit of 0% will allow the unit to run up to the
unit’s maximum frequency. A sound limit of 100% will
not allow the unit to run above the minimum frequency.
All other sound limit values are linear between these 2
points.
A sound limit schedule must be programmed under
the Schedule key when sound limiting is utilized. The
schedule defines the time period that sound limiting
will be active.
Sound Limiting is only possible if the option is enabled
by both the OPTIONS Key selection and the factory
programmable password protected Unit Setup Mode.
If Sound Limiting is disabled under the
Unit Setup Mode, nothing relating to
Sound Limiting will show up on any
display screen or printout.
ISN Sound Limit Setpoint
The ISN Sound Limit Setpoint can be set via the ISN
II comms. The control panel will only accept a Sound
Limit Setpoint from the ISN if the control panel is in
Remote Control Mode. If the control panel is in Local
Control Mode, the ISN setpoint will be ignored. The
minimum and maximum allowable values will be the
same as the minimum and maximum allowable values
for the Sound Limit Setpoint under the PROGRAM key.
If these values are exceeded, the minimum or maximum
value will be used.
Contact a local YORK ISN Representative for details
on ISN controls and capabilities.
Remote Sound Limit
The Sound Limit Setpoint can be set via the Remote
Sound Limit analog input. A zero signal input (0% input)
equates to the minimum sound limit setpoint as defined
under the PROGRAM key Sound Limit Setpoint. A full
scale signal input (100% input) equates to the maximum
sound limit setpoint as defined under the PROGRAM
key Sound Limit Setpoint. The input is linear and may
be adjusted between 0% (minimum sound limiting) and
100% (maximum sound limiting) points.
This input may be used either in Local or Remote Con-
trol Mode. The input will be ignored if the Remote
Sound Limit is disabled under the OPTIONS key. Once
a change to the input is registered, a timer is set to the
value of the Remote Inputs Service Time as program-
mable under the Unit Setup Mode at the factory for the
default value of 15 minutes. The low limit is 5 minutes
and the high limit is 60 minutes. The Remote input will
be ignored until this timer expires. The timer assures
that rapid changes in a remote reset signal don’t result
in poor temperature control and excessive compressor
cycling. In most instances, this timer will not need to
be changed, since reset more often than 15 minutes will
create problems with chilled liquid temperature control.
Factory Service should be contacted if a timer change
is required.
Control board jumper JP6 must be positioned correctly
to receive either a voltage (0-10VDC or 2-10VDC) or
current (0-20mA or 4-20mA) signal. Place the jumper
in the “V” position for a voltage signal or mA for a cur-
rent signal (see FIG. 18, Page 132). The software must
be configured under the OPTIONS key for the type of
input signal to be used.
The maximum sound limit is achieved at either 10
VDC or 20 mA. Sending the minimum signal (0 VDC,
2 VDC, 0 mA, or 4 mA based on the OPTIONS key
setting) causes the sound limit to be set to its minimum
(no limiting) value.
