VDH Products MC 785-SC User manual

Description : MC 785-SC Step Control Doc.nr.: 022091
Type: MANUAL Number of pages: 32 Version: V2.3
File: Do022091 MC785-SC v23 EN.wpd
Software: MC785-SC V2.11 By: BJB Date: 19-10-2009
VDH Products BV - Roden - Holland Signed: File: Doc'02
MC 785-SC
Operating Manual
(Wall and panel mounting)

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 2 of 32
The information contained in this document is assumed to be accurate. However VDH Products BV accepts no liability
for eventual mistakes or errors and has the right to change this document without notice.
Table of contents
1. Technical specifications ........................................................... 3
General ........................................................................ 3
Front .......................................................................... 3
Inputs and outputs ............................................................... 4
2. Functional specifications ........................................................... 4
3. Control ........................................................................ 6
General ........................................................................ 6
Switching the controller on and off. ................................................... 6
Password. ...................................................................... 6
Readout and setting the clock. ...................................................... 6
The SUCTION part (compressor-side) ................................................. 7
Readout selection on the SUCTION display. ............................................ 7
Showing status of the compressors. .................................................. 7
Readout or changing the suction pressure (/temperature) setpoint. ........................... 7
Setting a compressor in or out of service. .............................................. 7
Resetting operation hours of a particular compressor. ..................................... 7
The DISCHARGE part (condenser-side) ............................................... 8
Readout selection on the DISCHARGE display. .......................................... 8
Showing status of the condensers. ................................................... 8
Readout or changing the discharge pressure (/temperature) setpoint. ......................... 8
Setting a condenser in or out of service. ............................................... 8
Resetting operation hours of a particular condenser. ...................................... 8
4. Programming internal settings ....................................................... 9
Parameter table ................................................................. 9
*) Table of assignment of relay outputs ................................................18
$) Table of assignment of analog outputs (0-10Vdc) ......................................19
#) Table of assignment of digital inputs ................................................19
5. Alarms ........................................................................21
6. Function flow ...................................................................22
Operation of the Pband on the suction pressure side (Compressor-side) .......................22
Overview of the function flow for 4-compressors for the switching up and down of compressors .....22
Overview of the function flow for compressor with 5-cylinders ...............................23
Working of compressor control with unequal steps .......................................23
7. Front view ......................................................................26
8. Diagrams of connections ...........................................................27
10. Dimensions .....................................................................31

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 3 of 32
1. Technical specifications
General
Type : MC 785-SC (Step-Control)
Wall-mounting:
Housing : Grey plastic
Material : Polystyrol 454h KG 2 natur BASF
Dimensions : 213 x 180 x 85mm (whd)
Front : Polycarbonate (IP-44)
Panel-mounting:
Housing : Steel plate panel
Material : Steel in silver grey
Dimensions : 217 x 155 x 85mm (whd)
Panel cutout : min. 208 x 146mm (wh)
Front : Polycarbonate (IP-44)
Supply : 230 Vac; 50/60 Hz (-10/+5%).
Used power : 9 VA
Pressure range : 0/+50 Bar per 0.1 Bar (Suction: -40/+50°C per 0.1°C)
(Discharge: -30/+100°C per 0.1°C)
Accuracy : ± 0.5 % of the range
Operation temperature : -20/+50°C
Operation rel. humidity : 10/+90 % RH not condensing
Front
Displays : 4-digit display for suction pressure (SUCTION) with 7 day LEDs
4-digit display for discharge pressure (DISCHARGE) with 7 day LEDs
LED bars : 8 LEDs on/off and 8 LEDs delay, for maximal 8 compressors
8 LEDs on/off and 8 LEDs delay, for maximal 8 condenser fans
Keys : ON/OFF = On/off key controller with LED indication
= Clock key with LED indication
PRG = Program key with LED indication
RESET/ALARM = Reset alarm key with LED indication
(2x) = Up keys
(2x) = Down keys
SET (2x) = Setpoint keys with LED indication
SELECT (2x) = Display select keys at displays
MODE/SELECT (2x) = Mode select keys
LEDs at displays : Bar (2x) = LED indications for readout in Bar
OC (2x) = LED indications for readout in degrees Celsius
Hrs (2x) = LED Indications for readout in operation hours
% (2x) = LED indications for readout in percentage
(2x) = LED indications control is increasing
(2x) = LED indications control is decreasing
Service (2x) = LED indications service
Fail (2x) = LED indications fail
(2x) = LED indications alarm

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 4 of 32
Inputs and outputs
Pressure gauges : Pressure sensor-1 Suction (4/20mA signal, PX77/2: 2-wire system)
Pressure sensor-2 Discharge (4/20mA signal, PX77/2: 2-wire system)
Temperature sensors : SM811 temperature sensor-1 Suction (1KOhm PTC, 2-wire)
SM811 temperature sensor-2 Discharge (1KOhm PTC, 2-wire)
Analog outputs : Out-1 [01] (0/10Vdc signal, 2-wire (Rb min. 10 Kohm)
Out-2 [02] (0/10Vdc signal, 2-wire (Rb min. 10 Kohm)
Communications : RS485 Network (2-wire shielded; A,B,GND)
I2C-bus (extension-bus) (2-wire shielded; SDA, SCL, 0V)
Relays : Relay-1 [01] programmable. (C/NO/NC, 250Vac/10A not inductive)
Next relays have one common;
Relay-2 [02] programmable (NO, 250Vac/10A not inductive)
Relay-3 [03] programmable (NO, 250Vac/10A not inductive)
Relay-4 [04] programmable (NO, 250Vac/10A not inductive)
Relay-5 [05] programmable (NO/NC, 250Vac/10A not inductive)
2. Functional specifications
The MC 785-SC is an 8-stage step controller, which controls maximal 8 compressors and 8
condenser fans stepping up or down, based on the measured suction and discharge pressure and its
setpoints.
To control stepping up or down the controller can be set to the following choices:
Compressor control: On/off control, with or without valve lifting
(x-stage compressors) or
Frequency control
Condenser control: On/off control or
Frequency control
The controller can also step up or down a compressor or condenser, based on the total operation
hours or based on the power of the compressors or condensers.
It is also possible to disable compressors or condensers for maintenance or when a failure occurs.
To safeguard the control it is possible to set:
a minimum and maximum pressure alarm, a minimum and maximum pressure failure,
a minimum and maximum temperature alarm, a minimum and maximum temp. failure.
All inputs and outputs can be assigned thru setting internal parameters, so an efficient use of the
inputs and outputs is possible. If not enough inputs or outputs are available on the controller these
can be extended by use of extra LMS Modules connected at the I2C-bus.
At max the following LMS modules can be connected to the controller;
4 extra LMS-Relay-Modules, with 4 relays per module (uses a 100mA per module)
4 extra LMS-Analog-out-Modules, with 4 analog outputs per module (uses 10mA /mod)
4 extra LMS-Digital-in-Modules, with 6 digital inputs per module (uses 10mA/module)
To use these modules sufficient Supply-Module(s) must be used, see connection drawing 001822.

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 5 of 32
5 relay outputs and 2 analog outputs are standard on the MC785-SC, there are no digital inputs
available, all other needed outputs can be obtained thru extra LMS-modules.
Output(s) can by assigned to:
Compressor on relay
Compressor no load on relay
Compressor 50% relay for 2-stage (valve lifting) compressors.
Compressor 66% relay + 33% relay for 3-stage (valve lifting) compressors.
Compressor 75% relay + 50% relay + 25% relay for 4-stage (valve lifting) compressor.
Compressor 80% relay + 60% relay + 40% relay + 20% relay for 5-stage (valve lifting) compr.
Attention: For compressors with more cylinders only the first valve lifting relay
will be assigned, the following relays required will be assigned
automatically after the previous relay(s).
e.g. Compressor-1 as 4-stage compressor (Parameter P110=4) and the first valve lifting
relay assigned to relay 3 of the first LMS Relay Module (Parameter P113 = “1 3")
gives: Relay-3 of LMS-Relay-Module 1 = 75% valve lifting contact,
Relay-4 of LMS-Relay-Module 1 = 50% valve lifting contact and
Relay-1 of LMS-Relay-Module 2 = 25% valve lifting contact.
Compressor analog output 0...10Vdc
Condenser on contact
Condenser 50% / 100% relay for a 2-stage condenser.
Condenser analog output 0...10Vdc
Input(s) can by assigned to:
Compressor failure (with NC (normally closed) or NO (normally open) input contact)
Condenser failure (with NC (normally closed) or NO (normally open) input contact)
A general alarm is also available to be assigned. This relay is normally active C-NO is closed and
when an alarm occurs, which has not been reset, the relay switches off C-NC is closed.
All settings and controls can be authorised by a password, to prevent unauthorised using of the
controller.
There is also a RS485-network available on the controller for controlling the MC785-SC by a PC.
For this job the controller must be attached to a PC-interface and the PC must have an installed
software program for this job.

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 6 of 32
3. Control
The MC785-SC is divided into two parts: on the left side is the compressor part (SUCTION) and on
the right side is the condenser part (DISCHARGE).
Both these parts are almost identical for control or readout.
The current status of the controller is shown on the front.
General:
Switching the controller on and off.
By pressing the ON/OFF key the controller can be switched on or off.
Password.
Before any change can be made, the controller will ask for a password.
In the SUCTION display appears “Code” and in the DISCHARGE display “- - - -“.
By pressing the UP or DOWN keys the last number will be changed, set it to the right number
(see parameter 999). By pressing the SELECT key the next number can be set (with the UP or
DOWN keys). All four numbers must be set to the correct code (P 999) and, as a last action,
press the SELECT key.
If the code is correct, the settings of the controller can now be changed. The correct password
can be used for 2 minutes, after which time it deactivates so that the controller is locked
again.
The password can be set at the internal parameter P999 and is set on a default value as shown
in the parameter table.
Attention: Remember a set password well and keep it in a safe place!
Readout and setting the clock.
Press the CLOCK key to readout the time on the DISCHARGE display.
To set the clock, first readout the clock as above, then press the right SELECT key in order to
change the hours and minutes with the right UP and/or DOWN keys. Then press the right
SELECT key again to change the day setting with the right UP and/or DOWN keys. Finally,
press the right SELECT key yet again to activate the new time setting.
If no key is pressed for 10 seconds, the controller will return to its normal function.

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 7 of 32
The SUCTION part (compressor-side):
Readout selection on the SUCTION display.
By pressing the left SELECT key next to the SUCTION display once or more, the following
values can be shown on the display:
SThe suction pressure in Bars, LED Bar next to the display lights up.
SThe calculated suction temperature (depends on coolant) in degrees Celsius, LED’s
Bar and OC light up.
SThe suction temperature, of temperature sensor-1, in degrees Celsius, LED OC lights
up.
SThe operation hours of one of the compressors, to select another compressor, press
the left UP or DOWN keys. To show which compressor has been selected for readout,
the corresponding LED in the compressor bar will light up and the LED Hrs. will light
up.
SCurrent control signal in percentage, LED % lights up.
Further, there are two more LEDs ( and ) in the SUCTION display panel, these LED’s
indicate if the control signal is increasing or decreasing the compressor power.
Showing status of the compressors.
In the COMPRESSOR panel the status of the compressors is shown in different ways which
can be selected by the left MODE/SELECT key. These readout modes are;
SNormally the LED’s Service and Fail will not be lit, then the LED bars indicate:
Upper LED bar shows which compressors are active.
Lower LED bar shows which compressors are running in time delay.
Or
SLEDs Service and Fail are lit, then the LED bars indicate:
Upper LED bar shows which compressor is in service.
(These compressor(s) will not be selected for controlling by the controller).
Lower LED bar shows which compressor is in failure.
Readout or changing the suction pressure (/temperature) setpoint.
By pressing the left SET key, the suction pressure setpoint is shown in the SUCTION display.
To indicate this the Bar lights up. By pressing the left SELECT key, the setpoint will be shown
in degrees Celsius (also adjustable), LEDs Bar and OC light up.
To change the setpoint value now press the left UP or DOWN keys. 10 seconds after the keys
have been released the new setpoint will be active and the controller will return to its normal
display function again. Notice that the controller calculates the temperature signals to pressure
signals and controls on the pressure signals.
Setting a compressor in or out of service.
To put a particular compressor out of function, it must be set in service.
To see which compressors are in service press the PRG key together with the left
MODE/SELECT key. The LED Service will light up and the LED bars show:
Upper LED bar shows which compressors are in service and
Lower LED bar shows the currently-selected compressor.
With the left UP and DOWN keys another compressor can be selected. The compressor to be
put in or out service can be put in or out of service by pressing the left MODE/SELECT key.
Resetting operation hours of a particular compressor.
Read out the operation hours on the SUCTION-display by pressing the left SELECT key once
or more, until the LED Hrs lights up. Then select the compressor which has to be set to zero
with the left UP and/or DOWN keys. Now press the RESET/ALARM key, hold it down and
press simultaneously on the left MODE/SELECT key to set the selected compressor operation
hours to zero.

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 8 of 32
The DISCHARGE part (condenser-side):
Readout selection on the DISCHARGE display.
By pressing the right SELECT key next to the DISCHARGE display once or more, the following
values can be shown on the display:
SThe discharge pressure in Bars, LED Bar next to the display lights up.
SThe calculated discharge temperature (depends on coolant) in degrees Celsius, LED’s
Bar and OC light up.
SThe discharge temperature, of temperature sensor-2, in degrees Celsius, LED OC lights
up.
SThe operation hours of one of the condensers, to select another condenser, press the
right UP or DOWN keys. To show which condenser has been selected for readout, the
corresponding LED in the condenser bar will light up and the LED Hrs. will light up.
SCurrent control signal in percentage, LED % lights up.
Further, there are two more LEDs ( and ) in the DISCHARGE display panel. These LEDs
indicate if the control signal is increasing or decreasing the condenser power.
Showing status of the condensers.
In the CONDENSER panel the status of the condensers is shown in different ways which can
be selected by the right MODE/SELECT key. These readout modes are:
SNormally the LEDs Service and Fail will not be lit, then the LED bars indicate:
Upper LED bar shows which condensers are active.
Lower LED bar shows which condensers are running in time delay.
Or
SLEDs Service and Fail are lit, then the LED bars indicate:
Upper LED bar shows which condenser is in service.
(These condenser(s) will not be selected for controlling by the controller).
Lower LED bar shows which condenser is in failure.
Readout or changing the discharge pressure (/temperature) setpoint.
By pressing the right SET key, the discharge pressure setpoint is shown in the DISCHARGE
display. To indicate this the Bar lights up. By pressing the right SELECT key the setpoint will be
shown in degrees Celsius (also adjustable); LEDs Bar and OC light up.
To change the setpoint value now press the right UP or DOWN keys. 10 seconds after the keys
have been released the new setpoint will be active and the controller will return to its normal
display function again. Notice that the controller calculates the temperature signals to pressure
signals and controls on the pressure signals.
Setting a condenser in or out of service.
To put a particular condenser out of function, it must be set in service.
To see which condensers are in service press the PRG key together with the right
MODE/SELECT key. The LED Service will light up and the LED bars show:
Upper LED bar shows which condensers are in service and
Lower LED bar shows the currently-selected condenser.
With the right UP and DOWN keys another condenser can be selected. The condenser to be
put in or out of service can be put in or out of service by pressing the right MODE/SELECT
key.
Resetting operation hours of a particular condenser.
Read out the operation hours on the DISCHARGE-display by pressing the right SELECT key
once or more, until the LED Hrs lights up. Then select the condenser which has to be set to
zero with the right UP and/or DOWN keys. Now press the RESET/ALARM key, hold it down
and press simultaneously on the right MODE/SELECT key to set the selected condenser
operation hours to zero.

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 9 of 32
4. Programming internal settings
By pressing the PRG key for more than 5 seconds, the Internal Parameter Menu is entered. In the
SUCTION display a P appears with a number behind it. With the left UP and/or DOWN keys the required
parameter can be selected.
The value of the selected parameter is shown in the DISCHARGE display. By pressing the UP and/or DOWN
keys, the value can be adjusted.
If during 30 seconds no key is touched or the ON/OFF key is pressed, the display reverts to the normal
operation mode.
Parameter table.
P-Nr Description Range Unit De-
fault
Parameters General
P 10
P 11
P 12
P 13
P 14
P 15
P 16
P 17
P 18
P 19
P 20
P 21
P 22
P 23
P 24
P 25
P 26
Minimal adjustable pressure setpoint
compressor
Maximal adjustable pressure setpoint
compressor
P-band compressor
Maximum suction pressure before the first
compressor will be switched on without delay
Switch on delay for the next step
Time delay for next compressor step
Time delay for previous compressor step
Type of compressor control
0 = Switching up/down based on running
hours (with equal capacities)
1 = Switching up/down based on longest
on/off (with equal capacities)
2 = Capacity calculation (with unequal
capacities)
Compressor strategy
0 = None restrictions
1 = Let active compressor by active
2 = Switch compressors only up
Minimum capacity gain per step (as P17=2)
Minimum time between switching the same
compressor off and on
No-load running time on starting
compressor (valves are lifted)
Minimum on-time of compressor
Pumping-out pressure value
Pumping-out pressure active
Pressure release for economizer
Differential economizer release
-1..50,0
0..50,0
0,1..50,0
-1.0..50.0
1..600
1..600
1..600
0..2
0..2
0,1..300,0
0..999
0..30
0..999
-1,0..50,0
0=no 1=yes
-1,0..50,0
0,1..0,5
Bar
Bar
Bar
Bar
Sec.
Sec.
Sec.
-
-
kW
Sec.
Sec.
Sec.
Bar
-
Bar
Bar
1,0
50,0
8,0
10.0
30
300
30
0
0
1,0
120
3
30
1,0
0 (no)
2,3
0,3

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 10 of 32
P-Nr Description Range Unit De-
fault
P 30
P 31
P 32
P 35
P 36
P 37
Minimum adjustable pressure setpoint
Condenser
Maximum adjustable pressure setpoint
Condenser
P-band condenser control
Switching up time between the condensers
Switching down time between the condensers
Type of condenser control
0 = Switching up/down on running hours
(equal capacities)
1 = Switching up/down on set sequence
(1,2,3,4.....4,3,2,1)
0..50,0
0..50,0
0,1..50,0
1..600
1..600
0..1
Bar
Bar
Bar
Sec.
Sec.
-
1,0
50,0
8,0
300
30
0
P 40
P 41
Suction temperature sensor(sensor-1)
0 = Absent
1 = Present, readout only
2 = Present, readout and alarms
Discharge temperature sensor (sensor-2)
0 = Absent
1 = Present, readout only
2 = Present, readout and alarms
3 = Present, outdoor temperature for
Delta T control
0..2
0..3
-
-
0
0
P 42
P 43
P 44
P 45
P 46
P 47
Minimum suction temp. sensor alarm
Minimum suction temp. sensor failure
(Everything switches off)
Maximum discharge temp. sensor alarm
Maximum discharge temp. sensor failure
(Everything switches off)
Offset suction temperature sensor
Offset discharge temperature sensor
-40..50,0
-40..50,0
-40..100,0
-40..100,0
-10..10,0
-10..10,0
OC
OC
OC
OC
OC
OC
-40,0
-40,0
100,0
100,0
0,0
0,0
P 50
P 51
P 52
P 60
Low pressure alarm input (see table)
Fluid level too low warning input
(see table)
Level input gives fatal error
Alarm relay (normally powered)
(see table)
-- .. 4nc6
-- .. 4nc6
0=no,
1=yes
-- .. 4 7
- #
- #
- *
--
--
--
P 70
P 71
P 72
P 73
P 80
P 81
P 82
Suction pressure corresponding to 4.0 mA
Suction pressure corresponding to 20.0 mA
Offset pressure sensor suction pressure
Read out suction pressure senor in 0,01 Bar
Discharge pressure corresponding to 4.0 mA
Discharge pressure corresponding to 20.0 mA
Offset pressure sensor discharge pressure
-1,0..50,0
-1,0..50,0
-10..10,0
0=no,
1=yes
-1,0..50,0
-1,0..50,0
-10..10,0
Bar
Bar
Bar
-
Bar
Bar
Bar
0,0
25,0
0,0
0
0,0
25,0
0,0
P 90
P 91
P 92
P 93
Coolant type:
0 = unknown
1 = R22
2 = R134A
3 = R404A (bubble and dew point)
4 = R407A (bubble and dew point)
5 = R407C (bubble and dew point)
6 = R717 (Ammoniac)
7 = R507
Super heat detection active (0=no, 1=yes)
Super heat warning
Super heat alarm
0..7
0..1
0,0..50,0
0,0..50,0
-
-
Kelvin
Kelvin
0
0
8,0
7,0

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 11 of 32
P-Nr Description Range Unit De-
fault
P 95
P 96
P 97
Outdoor temp. control active (0=no, 1=yes)
Delta T condenser with outdoor temperature
Maximum pressure set point condenser
0..1
1,0..50,0
0,0..50,0
-
Kelvin
Bar
0 (no)
10,0
50,0
P100
P101
P102
P105
P106
P107
Minimum pressure alarm suction side
Minimum pressure alarm suction side delay
Minimum pressure failure suction side
(This is not delayed and the compressors
are blocked)
Maximum pressure alarm discharge side
Maximum pressure alarm discharge side delay
Maximum pressure failure discharge side
(This is not delayed and the compressors
and condensers are blocked)
-1,0..50,0
0..999
-1,0..50,0
-1,0..50,0
0..999
-1,0..50,0
Bar
Sec.
Bar
Bar
Sec.
Bar
0,5
10
0
18,0
10
20,0
Parameters for Compressors 1 to 8
P110
P111
P112
P113
P114
P115
P116
P117
P118
P119
P120
P121
P122
P123
Compressor-1 type:
0 = not present
1 = on/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
7 = FRQ 1-Stage frequency controlled
Power Compressor-1 in KW
On/off relay Compressor-1
Valve lifting relay Compressor-1
For no-load running, relay is active when
starting
First valve lifting relay ..%
Percentage depends on number of
cylinders, subsequent cylinders are
assigned automatically hereafter. (For
operation see page 5)
Analog output Compressor-1 (0-10V)
Failure input Compressor-1
High pressure input Compressor-1
Failure oil pressure contact-input
Compressor-1
Operation-switch input
Pause input
Economizer relay
Minimum percentage output frequency control
Maximum percentage output frequency control
0..7
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
1 .. 200
1 .. 200
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
%
%
1
0.1
--
--
--
--
--
--
–-
–-
–-
--
70
140

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 12 of 32
P-Nr Description Range Unit De-
fault
P130
P131
P132
P133
P134
P135
P136
P137
P138
P139
P140
P141
Compressor-2 type:
0 = Not present
1 = On/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
Power Compressor-2 in KW
On/off relay Compressor-2
Valve lifting relay Compressor-2
For no-load running, relay is active when
starting
First valve lifting relay ..%
Percentage depends on number of cylinders,
subsequent cylinders are assigned
automatically hereafter. (For operation
see page 5)
Analog output Compressor-2 (0-10V)
Failure input Compressor-2
High pressure input Compressor-2
Failure oil pressure contract-input
Compressor-2
Operation-switch input
Pause input
Economizer relay
0..6
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
0
0.1
--
--
--
--
--
--
–-
–-
–-
--
P150
P151
P152
P153
P154
P155
P156
P157
P158
P159
P160
P161
Compressor-3 type:
0 = Not present
1 = On/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
Power Compressor-3 in KW
On/off relay Compressor-3
Valve lifting relay Compressor-3
For no-load running, relay is active when
starting
First valve lifting relay ..%
Percentage depends on number of cylinders,
subsequent cylinders are assigned
automatically hereafter. (For operation
see page 5)
Analog output Compressor-3 (0-10V)
Failure input Compressor-3
High pressure input Compressor-3
Failure oil pressure contact-input
Compressor-3
Operation-switch input
Pause input
Economizer relay
0..6
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
0
0.1
--
--
--
--
--
--
–-
–-
–-
--

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 13 of 32
P-Nr Description Range Unit De-
fault
P170
P171
P172
P173
P174
P175
P176
P177
P178
P179
P180
P181
Compressor-4 type:
0 = Not present
1 = On/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
Power Compressor-4 in KW
On/off relay Compressor-4
Valve lifting relay Compressor-4
For no-load running, relay is active when
starting
First valve lifting relay ..%
Percentage depends on number of cylinders,
subsequent cylinders are assigned
automatically hereafter. (For operation
see page 5)
Analog output Compressor-4 (0-10V)
Failure input Compressor-4
High pressure input Compressor-4
Failure oil pressure contact-input
Compressor-4
Operation-switch input
Pause input
Economizer relay
0..6
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
0
0.1
--
--
--
--
--
--
--
–-
–-
--
P190
P191
P192
P193
P194
P195
P196
P197
P198
P199
P200
P201
Compressor-5 type:
0 = Not present
1 = On/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
Power Compressor-5 in KW
On/off relay Compressor-5
Valve lifting relay Compressor-5
For no-load running, relays is active when
starting
First valve lifting relay ..%
Percentage depends on number of cylinders,
subsequent cylinders are assigned
automatically hereafter. (For operation
see page 5)
Analog output Compressor-5 (0-10V)
Failure input Compressor-5
High pressure input Compressor-5
Failure oil pressure contact-input
Compressor-5
Operation-switch input
Pause input
Economizer relay
0..6
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
0
0.1
--
--
--
--
--
--
--
–-
–-
--

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 14 of 32
P-Nr Description Range Unit De-
fault
P210
P211
P212
P213
P214
P215
P216
P217
P218
P219
P220
P221
Compressor-6 type:
0 = Not present
1 = On/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
Power Compressor-6 in KW
On/off relay Compressor-6
Valve lifting relay Compressor-6
For no-load running, relay is active when
starting
First valve lifting relay ..%
Percentage depends on number of cylinders,
subsequent cylinders are assigned
automatically hereafter. (For operation
see page 5)
Analog output Compressor-6 (0-10V)
Failure input Compressor-6
High pressure input Compressor-6
Failure oil pressure contact-input
Compressor-6
Operation-switch input
Pause input
Economizer relay
0..6
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
0
0.1
--
--
--
--
--
--
--
–-
–-
--
P230
P231
P232
P233
P234
P235
P236
P237
P238
P239
P240
P241
Compressor-7 type:
0 = Not present
1 = On/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
Power Compressor-7 in KW
On/off relay Compressor-7
Valve lifting relay Compressor-7
For no-load running, relay is active when
starting
First valve lifting relay ..%
Percentage depends on number of cylinders,
subsequent cylinders are assigned
automatically hereafter. (For operation
see page 5)
Analog output Compressor-7 (0-10V)
Failure input Compressor-7
High pressure input Compressor-7
Failure oil pressure contact-input
Compressor-7
Operation-switch input
Pause input
Economizer relay
0..6
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
0
0.1
--
--
--
--
--
--
--
–-
–-
--

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 15 of 32
P-Nr Description Range Unit De-
fault
P250
P251
P252
P253
P254
P255
P256
P257
P258
P259
P260
P261
Compressor-8 type:
0 = Not present
1 = On/off
2 = 2-Cylinder (0-50-100%)
3 = 3-Cylinder (0-33-66-100%)
4 = 4-Cylinder (0-25-50-75-100%)
5 = 5-Cylinder (0-20-40-60-80-100%)
6 = Screw compressor (0-50-75-100%)
Power Compressor-8 in KW
On/off relay Compressor-8
Valve lifting relay Compressor-8
For no-load running, relay is active when
starting
First valve lifting relay..%
Percentage depends on number of cylinders,
subsequent cylinders are automatically
assigned hereafter. (For operation see
page 5)
Analog output Compressor-8 (0-10V)
Failure input Compressor-8
High pressure input Compressor-8
Failure oil pressure contact-input
Compressor-8
Operation-switch input
Pause input
Economizer relay
0..6
0.1..300.0
-- .. 4 7
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-- .. 4nc6
-- .. 4nc6
–- .. 4nc6
–- .. 4nc6
–- .. 4 7
-
KW
- *
- *
- *
- $
- #
- #
S#
- #
- #
- *
0
0.1
--
--
--
--
--
--
--
–-
–-
--
Parameters for Condensers 1 to 8 fans
P270
P271
P272
P273
P274
P275
P276
Condenser-1 type:
0 = Not present
1 = On/off
2 = 2-speed (0-50%-100%)
3 = FRQ frequency controlled
On/off relay Condenser-1
Relay for 50% 100%
Relay is active at 100% drive
Analog output Condenser-1 (0-10V)
Failure input Condenser-1
Minimum percentage output frequency control
Maximum percentage output frequency control
0..3
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
1 .. 200
1 .. 200
-
- *
- *
- $
- #
%
%
1
--
--
--
--
50
100
P290
P291
P292
P293
P294
Condenser-2 type:
0 = Not present
1 = On/off
2 = 2-speed (0-50%-100%)
On/off relay Condenser-2
Relay for 50% 100%
Relay is active at 100% drive
Analog output Condenser-2 (0-10V)
Failure input Condenser-2
0..2
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-
- *
- *
- $
- #
0
--
--
--
--

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 16 of 32
P-Nr Description Range Unit De-
fault
P310
P311
P312
P313
P314
Condenser-3 type:
0 = Not present
1 = On/off
2 = 2-Speed (0-50%-100%)
Aan/uit relais Condenser-3
Relay for 50% 100%
Relay is active at 100% drive
Analog output Condenser-3 (0-10V)
Failure input Condenser-3
0..2
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-
- *
- *
- $
- #
0
--
--
--
--
P330
P331
P332
P333
P334
Condenser-4 type:
0 = Not present
1 = On/off
2 = 2-speed (0-50%-100%)
On/off relay Condenser-4
Relay for 50% 100%
Relay is active at 10o% drive
Analog output Condenser-4 (0-10V)
Failure input Condenser-4
0..2
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-
- *
- *
- $
- #
0
--
--
--
--
P350
P351
P352
P353
P354
Condenser-5 type:
0 = Not present
1 = On/off
2 = 2-speed (0-50%-100%)
On/off relay Condenser-5
Relay for 50% 100%
Relay is active at 100% drive
Analog output Condenser-5 (0-10V)
Failure input Condenser-5
0..2
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-
- *
- *
- $
- #
0
--
--
--
--
P370
P371
P372
P373
P374
Condenser-6 type:
0 = Not present
1 = On/off
2 = 2-speed (0-50%-100%)
On/off relay Condenser-6
Relay for 50% 100%
Relay is active at 100% drive
Analog output Condenser-6 (0-10V)
Failure input Condenser-6
0..2
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-
- *
- *
- $
- #
0
--
--
--
--
P390
P391
P392
P393
P394
Condenser-7 type:
0 = Not present
1 = On/off
2 = 2-speed (0-50%-100%)
On/off relay Condenser-7
Relay for 50% 100%
Relay is active at 100% drive
Analog output Condenser-7 (0-10V)
Failure input Condenser-7
0..2
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-
- *
- *
- $
- #
0
--
--
--
--

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 17 of 32
P-Nr Description Range Unit De-
fault
P410
P411
P412
P413
P414
Condenser-8 type:
0 = Not present
1 = On/off
2 = 2-speed (0-50%-100%)
On/off relay Condenser-8
Relay for 50% 100%
Relay is active at 100% drive
Analog output Condenser-8 (0-10V)
Failure input Condenser-8
0..2
-- .. 4 7
-- .. 4 7
-- .. 4 4
-- .. 4nc6
-
- *
- *
- $
- #
0
--
--
--
--
Parameters for external setpoints
P500
P501
P510
P511
P520
P521
External compressors setpoint input-1
External compressors setpoint-1
External compressors setpoint input-2
External compressors setpoint-2
External compressors setpoint input-3
External compressors setpoint-3
-- .. 4nc6
-1.0..50.0
-- .. 4nc6
-1.0..50.0
-- .. 4nc6
-1.0..50.0
- #
Bar
- #
Bar
- #
Bar
--
0.0
--
0.0
--
0.0
Parameters for Network
P800
P801 Network number Log interval 1..250 1..120 - Minute
s
15
Parameters Software/Series number etc.
P991
P992
P993
P999
Software version no.
Serial number
Production date (year/week)
Password
(0000 = password not active)
-
-
-
0000..9999
-
-
-
-
-
-
-
1234
Key to symbols:
*) = See table of assignment of relay outputs
#) = See table of assignment of digital inputs
$) = See table of assignment of analog outputs
Remarks about P13 to P15:
Whit P13 it is possible to enter a limit for switching on the first compressor. As soon as the
pressure is higher then P13 the first compressor will switch on without delay. The minimal off
time (P20) will still be valid.
If the value from P15 is lower then the value of P14 then the value of P14 will be used. If
another step has to switch on, the value of P15 will be used.
Remarks about P500 to P521:
When one or more inputs are closed the input with the lowest setpoint will be active as setpoint
for the compressors!
During the readout of the setpoint a flashing ‘c’ will indicate that an input is active. In this mode
the set point CANNOT be changed.

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 18 of 32
*) Table of assignment of relay outputs
Value Relay number On Controller/Module Contact
-- No relay assigned - -
0 1
0 2
0 3
0 4
0 5
Relay-1
Relay-2
Relay-3
Relay-4
Relay-5
MC785-SC controller C-NO-NC
NO common C
NO ,,
NO ,,
NO/NC ,,
1 1
1 2
1 3
1 4
1 5
1 6
1 7
Relay-1
Relay-2
Relay-3
Relay-4
Relay-5
Relay-6
Relay-7
LMS-relay-module-1
(JP1 with jumper and
JP2 with jumper)
C-NO-NC
C-NO
C-NO
C-NO
C-NO-NC
C-NO-NC
C-NO-NC
2 1
2 2
2 3
2 4
2 5
2 6
2 7
Relay-1
Relay-2
Relay-3
Relay-4
Relay-5
Relay-6
Relay-7
LMS-relay-module-2
(JP1 without jumper and
JP2 with jumper)
C-NO-NC
C-NO
C-NO
C-NO
C-NO-NC
C-NO-NC
C-NO-NC
3 1
3 2
3 3
3 4
3 5
3 6
3 7
Relay-1
Relay-2
Relay-3
Relay-4
Relay-5
Relay-6
Relay-7
LMS-relay-module-3
(JP1 with jumper and
JP2 without jumper)
C-NO-NC
C-NO
C-NO
C-NO
C-NO-NC
C-NO-NC
C-NO-NC
4 1
4 2
4 3
4 4
4 5
4 6
4 7
Relay-1
Relay-2
Relay-3
Relay-4
Relay-5
Relay-6
Relay-7
LMS-relay-module-4
(JP1 without jumper and
JP2 without jumper)
C-NO-NC
C-NO
C-NO
C-NO
C-NO-NC
C-NO-NC
C-NO-NC
Remarks:
The 4- and 7-relay type LMS modules may be mixed together but at maximum 4 relay modules
can be assigned.
So at minimum there are 5 relays available on MC 785-SC and at maximum there are
5+4x7=33 relays available MC785-SC(5) + 4x LMS 7-RELAY MODULE.

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 19 of 32
$) Table of assignment of analog outputs (0-10Vdc)
Value Analog output number On Controller/Module Signal
-- No output assigned - -
0 1
0 2 Analog-output-1 Analog-output-2 MC785-SC regelaar 0-10Vdc 0-10Vdc
1 1
1 2
1 3
1 4
Analog-output-1
Analog-output-2
Analog-output-3
Analog-output-4
LMS-analog-module-1
(JP1 with jumper and
JP2 with jumper)
0-10Vdc
0-10Vdc
0-10Vdc
0-10Vdc
2 1
2 2
2 3
2 4
Analog-output-1
Analog-output-2
Analog-output-3
Analog-output-4
LMS-analog-module-2
(JP1 without jumper and
JP2 with jumper)
0-10Vdc
0-10Vdc
0-10Vdc
0-10Vdc
3 1
3 2
3 3
3 4
Analog-output-1
Analog-output-2
Analog-output-3
Analog-output-4
LMS-analog-module-3
(JP1 with jumper and
JP2 without jumper)
0-10Vdc
0-10Vdc
0-10Vdc
0-10Vdc
4 1
4 2
4 3
4 4
Analog-output-1
Analog-output-2
Analog-output-3
Analog-output-4
LMS-analog-module-4
(JP1 without jumper and
JP2 wihtout jumper)
0-10Vdc
0-10Vdc
0-10Vdc
0-10Vdc
#) Table of assignment of digital inputs
Value Digital input number On Controller/Module Input contact
-- No input assigned - -
1 1
1 2
1 3
1 4
1 5
1 6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-1
(JP1 with jumper and
JP2 with jumper)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
2 1
2 2
2 3
2 4
2 5
2 6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-2
(JP1 without jumper and
JP2 with jumper)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
3 1
3 2
3 3
3 4
3 5
3 6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-3
(JP1 with jumper and
JP2 without jumper)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)

Operating manual Document nr. : 022091 Version : V2.3
MC 785-SC Client : General Page : 20 of 32
Value Digital input number On Controller/Module Input contact
4 1
4 2
4 3
4 4
4 5
4 6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-4
(JP1 without jumper and
JP2 without jumper)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
NO-C (make)
1nc1
1nc2
1nc3
1nc4
1nc5
1nc6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-1
(JP1 with jumper and
JP2 with jumper)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
2nc1
2nc2
2nc3
2nc4
2nc5
2nc6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-2
(JP1 without jumper and
JP2 with jumper)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
3nc1
3nc2
3nc3
3nc4
3nc5
3nc6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-3
(JP1 with jumper and
JP2 without jumper)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
4nc1
4nc2
4nc3
4nc4
4nc5
4nc6
Digital input-1
Digital input-2
Digital input-3
Digital input-4
Digital input-5
Digital input-6
LMS-dig-in-module-4
(JP1 without jumper and
JP2 without jumper)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)
NC-C (break)