Sub-Zero Mega Chill-3Comp User manual

3-COMP CHILLER CONTROLLER
INDEX
A. Introduction
B. Hardware Description
C. Control Actions
D. Control Board – LCD & LED
E. Description of Inputs / Outputs
F. Ke pad
G. Regulation of Room Temperature
H Setting the parameters
I. Technical Data
Introduction
The “MEGA CHILL-3Comp is a three compressor chiller controller . This
integrates all the required functions of the chiller.
It is very user friendly due to the LCD provided which gives all the parameters,
messages, alarms etc on the display. In addition to the LCD there are LED’s
provided for instant status on all controls in the system.

HARDWARE DESCRIPTION
The basic s stem comprises :
- Control (Displa ) board
- INPUT/OUTPUT board
WARNING :
HP, LP, Antifreeze faults are b default in manual reset mode. The remain in manual
reset mode until the user resets to normal conditions b pressing the CLEAR button.
These can be changed to auto reset b changing P4 parameter.
CONTROL ACTIONS
- Regulation of Chiller temperature based on the control sensor location.
Control Board :
LIQUID CRYSTAL DISPLAY (LCD)
The Liquid Cr stal Displa shows the values of the controlled parameters, the selected
set-point, the alarm thresholds and all other information concerning the controlled
variables.
DISPLAY t pes :
2 rows X 16 characters LCD
LIGHT EMITTING DIODES (LED)
LEDs INDICATING THE STATUS OF THE DEVICES
There are different LED indications on the control board front panel. The give the
following information :
- Red blinking LED “ALERT” : Indicates that there is a fault
- Red LED devices : Indicates that there is a fault in that particular device
- Green LED devices : Indicates that the device is OK
- Blank (inactive) LED indicates that the device is inactive.

DESCRIPTION OF INPUTS / OUTPUTS
ANALOGUE INPUTS
Probes
1. CONTROL : used as the main controlling probe based on which the setpoint will
regulate the s stem.
2. Condenser Inlet : Senses Condenser Inlet temperature
3. Condenser Outlet: Senses Condenser Outlet temperature.
4. Water Inlet : Senses Water (CHILLER) Inlet temperature
5. Water Outlet : Senses Water (CHILLER) Outlet temperature
6. Antifreeze : Used to trip compressors below AFT set point .
DIGITAL INPUTS
Controller manages the following protections :
- High Pressure trip for the compressor1(HP1)
- Low Pressure Trip for the compressor1.(LP1)
- Compressor Overload trip1(COMP O/L1)
- OSS - Oil Safet Switch (OSS1)
- Single Phase Preventor Trip1(SPP1)
- High Pressure trip for the compressor2(HP2)
- Low Pressure Trip for the compressor2.(LP2)
- Compressor Overload trip2(COMP O/L2)
- OSS - Oil Safet Switch (OSS2)
- Single Phase Preventor Trip2(SPP2)
- High Pressure trip for the compressor3(HP3)
- Low Pressure Trip for the compressor3.(LP3)
- Compressor Overload trip3(COMP O/L3)
- OSS - Oil Safet Switch (OSS3)
- Single Phase Preventor Trip3(SPP3)
- Condenser Fan1 O/L Trip (FAN O/L1 )
- Condenser Fan2 O/L Trip (FAN O/L2 )
- Condenser Fan3 O/L Trip (FAN O/L3 )
- Pump Overload Trip
- Evaporator Water Flow Switch Trip
The controller informs the user of a fault condition via a buzzer and an ALARM-
RELAY.
DIGITAL OUTPUTS (RELAY)
1. Chiller Pump
2. Compressor1
3. Condenser Fan1
4. Compressor2
5. Condenser Fan2
6. Compressor3
7. Condenser Fan3

8. Water SV
9. Alarm
10. Pumpdwn SV1
11. Pumpdwn SV2
12. Pumpdwn SV3
KEYPAD
START
Press and hold this ke for 4 seconds to bring the controller in an operative status from
the stand-b status in which it normall is after being powered on except if H2 parameter
is set to AUTOSTART mode.
STOP
Press and hold this ke for 4 seconds to stop the s stem and operate in Stand B mode.
MUTE
Press this ke for 1 second, to disable the buzzer and alarm rela .
RESET
Press and hold this ke for 4 seconds to reset HP,LPand antifreeze alarms which have
been set for MANUAL RESET incase P4 parameter is set to MANUALRESET mode.
TEMP
Press and hold this ke for 1 seconds to displa temperatures for all probes. Use up/down
ke to scroll through the various probes attached. To exit this mode, press the temp ke .
PRG, SEL, UP & DWN
Used to enter programming mode.
REGULATION OF CHILLER TEMPERATURE
The regulation of the Brine temperature is based on the CONTROL probe.

SET-POINT AND DIFFERENTIAL
Set-point is the temperature at which the chiller temperature has to be regulated, at which
time the compressor will go off. Differential is the temperature added after which the
compressor restarts. For example, if Set-point is 7oC and differential is 2oC, then
compressor will switch off at 7 oC and restart at 7+2 = 9oC.
*******ALARMS*******
Incase of all alarms corresponding LCD readouts and LED signals will displa ,and the
s stem will act accordingl . For example if there is an HP1 error, Compressor1 will trip
and restarts with the time dela .
PARAMETER SETTINGS :
All “working” parameters are protected with a hardware ke to prevent an
unauthorized access to the data. Press PRG + SEL for more than 5 seconds to enter the
parameter mode. To change an parameter PROKEY must be inserted before entering to
the programming mode.
Displa will flash parameter “t1” . Using UP/DOWN ke user can scroll all the
parameters . B pressing “SEL” ke user can view and change respective parameter
value. Press PRG to store and exit from that particular parameter. To End
Programming press SEL ke when LED displa shows EP
If ou do not press an button within 20 seconds after having entered this
procedure, the unit will return to normal operation without storing the values of the
modified parameters.
Setting and displaying set parameters.
Para Probe Set by Min Max Fac. M.U Variation
T1
Control Probe calibration.
It ma so happen that during the course of
time there ma be a slight offset in the actual
temperature and the temperature shown. For
example if the actual temperature is 20 oC
and the temperature on the controller shows
22 oC, set this parameter to -2 oC and once out
of this mode, the temperature will displa 20
oC (22-2 oC)
U -10 10 0 oC 0.5
T2 Antifreeze probe calibration.
Setting as in T1. U -10 10 0 oC 0.5
R1 Set point for compressor1 U R4 R3 10 oC 0.5
R2 Set point for compressor2 U R4 R3 7 oC 0.5

R3 Set point for compressor3 U R4 R3 7.5 oC 0.5
R4 Differential for compressor1 U 1.0 10.0 2.0 oC 0.5
R5 Differential for compressor2 U 1.0 10.0 2.0 oC 0.5
R6 Differential for compressor3 U 1.0 10.0 2.0 oC 0.5
R7
Maximum Cooling Setpoint
Once set at a particular range, this will not
allow the set point to go above this range and
below R4 setting.
Example: Setting this parameter at 250Cwill
not allow the set point to go above 250C.
Also if the temperature reaches 250C the
displa will show Ht (High Temp)
indicating that the temperature has gone
above the range in this parameter and at this
point the alarm will come on.
F R6 50 50 oC 0.5
R8
Minimum Cooling Setpoint
Use UP/DOWN ke s to get desired range &
press set ke to confirm.
Once set at a particular range, this will not
allow the set point to go below this range and
above R3 setting
Example: Setting this parameter at -300C
will not allow the set point to go below
-300C. Also if the temperature reaches -300C
the displa will show Lt (Low Temp)
indicating that the temperature has gone
below the range in this parameter and at this
point the alarm will come on.
F -30 R5 -30 oC 0.5
C1
Time delay for compressor1 restart
E.g. If this parameter is set at 3MIN,then
after cutting off the compresso1r at set
temperature compressor1 will not
Restart for a minimum of 3min.This time
dela is also active at power on of the s stem
.
F 0 20 3 Min 1
C2
Time delay for compressor2 restart
E.g. If this parameter is set at 3MIN,then
after cutting off the compressor2 at set
temperature compressor2 will not
Restart for a minimum of 3min.This time
dela is also active at power on of the s stem
.
F 0 20 3 Min 1
C3
Time delay for compressor3 restart
E.g. If this parameter is set at 3MIN,then
after cutting off the compressor3 at set
temperature compressor3 will not
Restart for a minimum of 3min.This time
dela is also active at power on of the s stem
.
F 0 20 3 Min 1
C4 Time delay between any two compressors
start.
F 0 120 10 Sec 1

E.g. If this Parameter is set to 30sec ,then
second compressor will come on after 30sec
dela from first compressor switch on.
F1
Fan Operating Mode
0=Fan Alwa s On
1=Fan on with compressor
F 0 1 0 Flag 1
F2
Starting Time of Fans
Fans will start these man seconds before the
compressor starts .
F 0 120 20 Sec 1
A0
AFT Probe Active
To activate Antifreeze(AFT) Probe
Function
0 = Disable AFT probe.
1 = Enable AFT probe.
F 0 1 0 Flag 1
A1 Antifreeze set point for AFT Probe F -30 R1 4 oC 1
A2 Differential for AFT Probe F 1 10 2 oC 1
P1
Flow switch alarm delayed at power on.
S stem will activate the alarm onl if the
error persists for more than P1 secs at s stem
start up.
F 0 120 5 Sec 1
P2
Flow Switch Alarm delay during normal
operation.
If this parameter is set at 10 seconds , the
s stem will activate the flow switch alarm
onl if the error persists for or more than 10
seconds .In this manner a false alarm can be
avoided during normal operation.
F 0 90 5 Sec 1
P3
Low Pressure Alarm delayed during
compressor start up
If this parameter is set at 30 seconds , the
s stem will activate the low pressure switch
alarm onl if the error persists for or more
than 30 seconds .In this manner a false alarm
can be avoided due to low pressure at
compressor start up.
F 0 120 40 Sec 1
P4
Reset of alarms.
0= Manual Reset for HP,OSS and AFT
alarms
1= Auto Reset for HP,OSS and AFT alarms
F 0 1 0 Flag 1
H0
PUMP Start Logic
PUMP with Comp
It defines Pump working logic.
0= Pump Alwa s On.
1= Pump On/Off with Comp.
F 0 1 0 Flag 1
H1 To activate Pumpdown procedure
This parameter is used to activate or
deactivate pumpdown procedure at ever
refrigeration c cle .
0 = Inactivate Pumpdown
F 0 1 0 Flag 0

1 = Activate Pumpdown
H2
AUTOSTART on power on.
0=Standb on power on.
1=Autostart on power on.
F 0 1 0 Flag 1
H3
Phase Errors
R Y B Phase Error
0= Inactive.
1= Active.
Incase of 0 s stem will ignore R Y B errors.
F 0 1 1 Flag 1
H4
UNIT1 SELECTION
0= Unit1 Inactive
1= Unit1 Active
Incase of 0 s stem will not activate
compressor1 and all its faults.
F 0 1 1 Flag 1
H5
UNIT2 SELECTION
0= Unit2 Inactive
1= Unit2 Active
Incase of 0 s stem will not activate
compressor1 and all its faults.
F 0 1 1 Flag 1
H6
UNIT3 SELECTION
0= Unit3Inactive
1= Unit3 Active
Incase of 0 s stem will not activate
compressor1 and all its faults.
F 0 1 1 Flag 1
H7
Fault in standby
It Enable/Disable fault sensing in standb
mode.
0 = Disable.
1 = Enable.
F 0 1 0 Flag 1
FO
Fault sense logic of digital inputs
0 = Faults at 0V.
1 = Faults at 230V.
F 0 1 0 Flag 1
LP
Keypad lock.
0= Ke pad Active
1=Ke pad Locked
U 0 1 0 Flag 1
FS Factory set parameters
1=Factor set parameters. F 0 1 0 Flag 1
EP
End programming mode.
Once in this mode press the SET ke . The
controller goes into the normal mode and all
settings are saved.
F Flag
Technical Specifications :
1. Analog Inputs : Japanese NTC thermistors
Resolution : 0.5 0C
Accurac : +/- 10C
2. Controlling Temp. Range : -30 to 50 0C

3. Digital Inputs : Potential Inputs 230Vac
4. Digital Output (Rela )
Rating : 230Vac, 8A (resistive) All digital outputs are fused
5. Operating Temperature +5 0C to +500C
6. Operating Humidit max 80% (non –condensing)
7. Mounting : Panel mounting t pe
8. Fuse :1.5A
9. Power Source :Transformer Rating
Input : 230Vac,50Hz
Output :
Secondar 1 : 9Vac,350mA
Secondar 2 : 10Vac,500mA
02 / 04.07.13