CLOCK SCHEDULE KEYPAD
This keypad requires a total of 49 keystrokes to sequence en-
tirely through the loop. See the keystrokes sequence table
for individual keystrokes information. In summary, the Clock
Schedule keypad provides:
l Current date and time
l Weekly and daily on-off time schedules
l 14 holiday
“off" schedules
l An over-ride function to counter a programmed “off” period
l And a Master “off” function to over-ride the daily, weekly,
and holiday schedules entirely.
Most of these function are self-explanatory. All can be
visualized in their place on the printed Clock Schedule table.
A brief explanation of some of these steps follow.
When shipped, each unit has the date and time set but the
clock control program de-activated.
De-activation of the daily and weekly clock control schedule
is accomplished by setting the
S1
display (the 10th press of
the “Clock Schedule” keypad) equal to “Off”.
If the operator wishes to activate the automatic control
schedule, including holidays,
S1
must be changed to Sun-
day, Monday, etc., or whichever day is to be considered the
first day of controlled operation. Subsequent keypresses will
set the time of start-up and shutdown.
Reference to the Clock Schedule Table will show that a se-
cond weekly control schedule may also be incorporated.
NOTE: On dual compressor units, it may be desirable to set
the clock schedules for each of the control panels at the same
values. At the very least, clock schedules on dual compressor
units must be turned “On”. This is accomplished by setting
“S1
First Day=Sun.
OVER-RIDE CONTROL
In the event the clock schedule time and holidays have been
pre-set, and it becomes desirable to turn the chiller “on” on
a scheduled “off” day, it is not necessary to re-enter the pro-
gram and alter the entire schedule.
Simply press the Clock Schedule keypad twice. “Over-ride
(Hours)=X.X”
will appear on the display. With the password
entered, press the “+/Yes” key. Numerical values for the
desired number of operating hours will be shown in the
display. Press enter to insert the time into the control memory,
and if water temperature, control power, and interlocks per-
mit, the unit will start.
Assuming that the chiller will not satisfy the water
temperature, or experience a fault condition, the unit will se-
quence through a controlled shutdown following passage of
the alloted hours.
" +/Yes”,
"
-/No”,
"
=/Enter”
These keys are used to input desired options, raise or lower
setpoints and protective settings, and enter the chosen value
or statement into the Microprocessor memory.
See the earlier paragraph headed “To Change A Setpoint”.
MANUAL VANE CONTROL
For service purposes, it’s sometimes necessary to put an
operating compressor into a manually controlled capacity
mode.
A password must be entered, and the “Manual Vane Con-
trol” key pressed. This display will immediately begin blink-
ing
“[
+] Load,
[
-]
Unload”. This flashing statement indicates
that the unit is in manual control and is in a holding position.
In this position other keys such as “Water Temp”, “Unit
Status”, “Motor Amps”, etc. may be pressed. They will display
the operating value, but in each case, the entire statement
will be flashing, indicating that the unit is under manual
capacity control. If, for example “Motor
Amps=XX”
is
flashing, pressing the “+/Yes” keypad will load the machine
and the increase will be reflected by an increase in the amp
value displayed, provided higher amperage is permissable.
Similarily, if unloading is desired, pressing the “-/No” keypad
will display a reduction in amps confirming that the com-
pressor has unloaded.
Remember, if the entire displayed message is flashing, the
unit is in Manual control. To return the control to automatic,
press the “Cancel, clear display” keypad.
If the chiller control is accidentally left under manual con-
trol, the display and manual operation will automatically
cancel itself after 10 minutes of no keystrokes.
“FAULT HISTORY”, “CLEAR FAULT”
If a unit trips due to a fault, the first press of the “Fault History”
keypad will display the cause. Pressing the keypad eight more
times will display the previous eight faults, thereby providing
a pattern for service analysis.
Following correction of the actual (current) fault, the “Clear
Fault” keypad must be pressed to permit restarting the unit.
Possible safety faults are listed below. (Words in parenthesis
are not displayed).
Some versions of software may also include “High Motor
Current” or “Low Motor Current”.
In all cases the general reason for the outage will be
self-explanatory.
NO TRANSITION (Starter)
LOW SUMP TEMP (Oil)
HIGH FEED TEMP (Oil)
LOW EVAP PRESS (Refrig)
HIGH DISCHARGE PRESS (Refrig)
HIGH DISCHARGE TEMP
SURGE (Compressor)
HIGH SUCTION TEMP (Refrig)
HIGH MOTOR TEMP (Guardistor)
STARTER FAULT (Overload)
LOW CHARGE SW (MLP)
NO EVAP FLOW (Water)
NO COND FLOW (Water)
LOW OIL PRESS (OP)
HIGH PRESS SW (MHP)
LVG EVAP WTR SEN
ENT EVAP WTR SEN
EVAPORATOR SEN (Refrig)
SUCTION SENSOR (Refrig)
LIQUID LINE SEN (Refrig)
ENT CND WTR SEN
LVG CND WTR SEN
DISCHARGE SEN (Refrig)
CONDENSER SEN (Refrig)
OIL FEED SENSOR
OIL SUMP SENSOR
OIL PRESS SEN
VANES OPEN
IM 403 I Page 27
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