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Wiring from remote "dry" contact (for
reset functions) should not exceed 25
ft. (8 m) and should be run in ground‑
ed conduit that does not carry any
wiring other than control wiring or
shielded cable. If an inductive device
(relay, contactor) is supplying these
contacts, the coil of the device must be
suppressed with a suppressor YORK
Part Number 031‑00808‑000 across
the inductive coil.
Remote Setpoint Reset
The chilled liquid leaving temperature setpoint pro-
grammed into the micro can be remotely adjusted to
a higher value using repeated timed closure of "dry"
contacts connected to Terminals 13 and 17 of TB4 in the
logic section of the control panel (See Section 1.12). The
duration of the contact closure will decide the amount
of adjustment. This is achieved as follows:
The maximum allowable reset value can be programmed
from 2°F - 40°F (1°C - 22°C), as appropriate to the
application - see Section 6.4. Once the maximum reset
is programmed, an input contact closure of 11 seconds
provides the maximum reset. Closure for less than 11
seconds will provide a smaller reset. For noise immunity,
the micro will ignore closures of less than 1 second. To
compute the necessary contact closure time to provide
a required Reset, use the following steps:
Reset Temp ={ (Contact Closure - 1sec) X Programmed Max Reset}
Offset
For example, with a programmed setpoint of 44°F (7°C),
after a 4 second pulse and a programmed maximum offset
of 40°F (22°C), the temperature offset would equal:
Reset Temp = (4 sec - 1 sec) X 40°F
10 sec
Reset Temp = 120°Fsec
10 sec
= 12°F (6°C)
JOHNSON CONTROLS
10 sec
To determine the new setpoint, add the reset to the
setpoint programmed into memory. In the example
above, if the programmed setpoint = 44°F (7°C), the
new setpoint after the 4 second contact closure would
be 44°F (7°C)+ 12°F (6°C) = 56°F (13°C). This new
setpoint can be viewed on the display by pressing the
Remote Reset Temperature/Range key.
To maintain a given offset, the contact closure signal
must be repeated every 30 seconds - 30 minutes. The
refresh is not accepted sooner than 30 seconds from
the end of the last PWM signal, but must be refreshed
before 30 minutes has elapsed. After 30 minutes, if no
refresh is provided, the setpoint will change back to its
original value.
After an offset signal, the new Remote
Setpoint may be viewed on the Remote
Reset Temperature Range display.
However, if this display is being viewed
when the reset pulse occurs, the set‑
point will not change on the display.
To view the new offset, first press any
other display key on the keypad and
then press the Remote Reset Tempera‑
ture Range key. The new setpoint will
then appear.
Remote Setpoint Reset will not operate
when a Remote Control Center Option
Kit is connected to the Micro. The
Remote Control Center will always
determine the setpoint.
Wiring from remote "dry" contact (for
reset functions) should not exceed 25 ft.
(8 m) and should be run in grounded
conduit that does not carry any wiring
other than control wiring or shielded
cable. If an inductive device (relay,
contactor) is supplying these contacts,
the coil of the device must be suppressed
with a suppressor YORK Part Number
031‑00808‑000 across the inductive
coil.
FORM 201.18-NM7
8
129
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