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EMS/BAS CONTROLS
The microprocessor is capable of REMOTE START/
STOP, REMOTE SETPOINT RESET, and REMOTE
CURENT RESET. These functions can be easily utilized
by connecting user supplied "dry" contacts to the
Microprocessor Board.
REMOTE START/STOP BY A CYCLING DEVICE OR
TIME CLOCK
Remote START/STOP is accomplished by connecting a
time clock or other "dry" contact in series with the flow
switch on terminals 13 & 14 of TB4. See Fig. 19 for the
location of the terminals. The contact must be closed to
allow the chiller to run. Any time the contact opens, the
chiller will shut down and the following status message
will be displayed.
S Y S # 1
N O
S Y S # 2
N O
Wiring from these contact should not exceed 25 ft. and
should be run in grounded conduit that does not carry any
wiring other than control wiring. Additionally, if an
inductive device (relay, contactor) is supplying these
contacts, the coil of the device must be suppressed with
a user supplied YORK P/N 031-00808 suppressor.
REMOTE SETPOINT RESET
(REMOTE RESET TEMP RANGE)
Remote Setpoint Reset allows resetting the setpoint
upward from the programmed value in memory. This is
accomplished by connecting a "dry" contact between
terminals 13 & 17 of TB4. See Fig. 19 for the location of
these terminals. Closing the contact for a defined period
of time allows reset of the setpoint upward by up to 40°F
above the setpoint programmed in memory.
The maximum desired reset must be programmed into
memory and can be a value of 02 to 40°F. This value will
vary according to the user's requirements. To program the
reset, press the REMOTE SETPOINT TEMP RANGE
key. The following message will appear.
R E M
S E T P O I N T
R E M
R A N G E
The display will indicate the REM SETPOINT which is
always equal to the chilled liquid setpoint programmed by
the CHILLED LIQUID TEMP/RANGE key plus the offset
from the remote reset signal. The display will also show
the REM RANGE which is the same as the maximum
reset required by the application. Key in the maximum
YORK INTERNATIONAL
R U N
P E R M
R U N
P E R M
=
2 0 . 0
=
4 0
° F
reset required for the application after REM RANGE and
press the ENTER Key to store the new value in memory.
Once the maximum reset is programmed, it will require a
contact closure of 21 seconds to achieve the maximum
reset. Closure for less than 21 seconds will provide a
smaller reset. For noise immunity, the micro will ignore
closures of less than 1 second.
To compute the offset for a given contact closure, use the
formulas below:
1. Programmed max. reset
20 seconds
2. (Time Closed-1) Reset per sec.
Example:
Programmed max reset - 30°; Time Closed = 9 sec.
1.
30°
=
1.5° per sec.
20 sec.
2. (9 sec. -1 sec.) 1.5° per sec. = 12° = Reset
To determine the new setpoints, add the reset to the
setpoint programmed into memory. In the example
above, if the programmed setpoint = 44°F, the new
setpoint after the 9 second contact closure would be 44°F
+ 12°F = 56°F. This new setpoint can be viewed on the
display by pressing the REMOTE RESET TEMP/
RANGE key.
To maintain a given offset, the micro must be refreshed
every 30 seconds - 30 minutes with a contact closure of
the required time period. It will not accept a refresh sooner
than 30 seconds after the end of the last PWM signal, but
must be refreshed before a period of 30 minutes expires
from the end of the last PWM signal.
After 30 minutes, if no refresh is provided, the setpoint will
change back to its original value. A refresh is nothing
more than a contact closure for the period required for the
desired offset.
NOTE: After an offset signal, the new REM SETPOINT
may be viewed on the REMOTE RESET TEMP
RANGE display. However, if this display is being
viewed when the reset pulse occurs, the setpoint
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
TEMP RANGE key. The new setpoint will then
appear.
Wiring from these contacts should not exceed 25 ft. and
should be run in grounded conduit that does not carry any
wiring other than control wiring. Additionally, if an
FORM 201.10-NM1
=
Reset per sec.
=
Reset
129
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