Dunham-Bush HRSC - D, Инструкция по эксплуатации и обслуживанию

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2.4. Do not allow the component boards to get wet,
(direct contact with water or condensation).
2.5 Disconnect power to the NC25 when plugging
in or unplugging a ribbon cable connector.
2.6 Disconnect power to the NC25 when changing a
chip on the board. Check to make sure that pin 1
of chip is in upper-left corner and that the chip is
inserted fully before reconnecting power.
2.7 Route ribbon cable and sensor wires away from
control and power wires.
2.8 Handle boards with care.
3. Operation of LCD Display NC25-4
The following instructions are for operation of the
NC25- 4 microcomputer with 2 x 40 character LCD
display.
3.1 To Display data from the menu
1. Press the MENU key.
2. Use the up or down arrow keys to select the
type of information desired. The main menu
items are: DATE & TIME SET
ALARMS
DIGITAL SENSORS
CONTROL POINTS
SETPOINTS A & B
AUTHORIZATION
ANALOG SENSORS
3. Press the ENTER key.
4. Use the up or down arrow keys to select the
desired data. For control points, additional
data can be viewed with the right and left
arrow keys. Press the right arrow key to
sequence through the following screens:
A. LAST ON/OFF - RUN T/Y - CYC
TIME TIME TIME TIME COUNT
LAST ON/OFF gives the time of day that the
control last turned on or off. The last on time
is not updated if a screw compressor is started
manually.
RUN T/Y gives the accumulated time that the
control point has been on today (T) since mid-
night and the accumulated run time during
yesterdays(Y) twenty-four hour period.
CYC gives the number of times that the control
point cycled off since midnight. It a feedback
digital input is associated with a control point
(EX: compressor) the digital input cycles are
recorded.
B. TOTAL RUN TIME = COUNT
TOTAL CYCLES = COUNT
TOTAL RUN TIME gives the number of hours the
control point has been on since memory clear
was performed. This records up to 65,000
hours.
TOTAL CYCLES gives the number of cycles
since a memory clear was performed. This
records up to 65,000 cycles.
C. -- CURRENT -- --
TARGET —
VALUE VALUE
VALUE VALUE
The values under CURRENT and TARGET give
different operating analog input values and
setpoints for different types of control points.
Screw compressor control points give current
and target leaving water temperature and
percent full load capacity. Fan type control
points give the current analog value and
target turn on and turn off setpoints.
NOTE: When displaying analog sensors, the PAGE
MODE key can be pressed to display two new
analog inputs after each arrow key is pressed. Press
PAGE MODE again to return to displaying one new
analog input.
3.2 To Reset All Control Points to Computer Control
1.
Press the RESET key. The display will show RESET
ALL CPs to COM MODE? N Y
2. Press the right arrow key to select Y.
3. Press the ENTER key. The reset will not be
accepted if a lockout control point is active.
Resolve the problem and reset again.
3.3 To Display Alarms
.
1. Press the MENU key.
2. Use the up or down arrow to select ALARMS.
3. Press ENTER. The day, time, and alarm code is
displayed.
4. Alarm 1 is the most recent alarm.
5. Press the down arrow to view previous alarms.
6. Check the data label to obtain the name of the
alarm. If the data label is not available, display
the digital input that corresponds to the alarm
number. If the digital input name is SPARE, then
display the control point that corresponds to
the alarm number. EX: If alarm code 29 has
occurred, then display digital input 29 or
control point 29 to determine the failure.
3.4 To Become Authorized
1. Select AUTHORIZATION on the main menu.
Press ENTER.
2. The current status will show VIEW, press the
authorization code (64) on the number keys.
3. Press ENTER. The current status will change to
PROG (program) if accepted. If no keys are
pressed for five minutes, or if the Authoriza-
tion screen is re-displayed, the authorization
to change setpoints is removed and the above
procedure must be repeated to log in.
3.5 To Alter Setpoint Data
1. You must be authorized and in the PROG
mode. See section 3.4.
2. Select SETPOINTS A & B on the main menu.
Press ENTER.
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