Operation Manual
Document nr. : 021171
Version : V1.0
MC 785D 0/+100
O
C
Client : General
Page : 4 of 20
In- and outputs
Sensors
: Temperature sensor 1 (Pt-100, 3-wire to DIN/IEC 751)
Temperature sensor 2 (Pt-100, 3-wire to DIN/IEC 751)
Temperature sensor 3 (Pt-100, 3-wire to DIN/IEC 751)
Temperature sensor 4 (Pt-100, 3-wire to DIN/IEC 751)
Digital inputs
: Night offset input (potential free input contact)
External alarm input (potential free input contact)
Analog output
: 2x 0/+10Vdc, Rbmin 10Kohm, programmable.
Relay outputs
: RY1 Alarm (C/NO/NC, 250Vac/10A not inductive)
Normally C-NO is closed, at alarm C-NC is closed.
The next relays have a central common;
RY2 Relay 2 programmable (NO, 250Vac/10A not inductive)
RY3 Relay 3 programmable (NO, 250Vac/10A not inductive)
RY4 Relay 4 programmable (NO, 250Vac/10A not inductive)
RY5 Relay 5 programmable (NO, 250Vac/10A not inductive)
2
Functional specifications.
To the MC 785D thermostat a maximum of four temperature sensors can be connected. As more
than one sensor is set active the MC785D controls on the average temperature of these sensors.
A maximum for four different setpoints can be programmed.
The MC785D thermostat has standard functions from 1 thermostat with 1 setpoint and 1 relay output
until 4 thermostats with 4 setpoints and 4 relay outputs. Also two-, three- or four-steps thermostat with
one setpoint available.
The MC 785D has the control functions cooling or heating. Also has the controller an alarm relay,
which becomes active as soon as the alarm levels are exceeded, a sensor is broken or the external
alarm input is closed.
The MC 785D has two analog outputs with a range of 0/+10Vdc. The function of these outputs can be
programmed as measuring signal, setpoint signal or a P(I) control for the cooling or heating.
The controller has two digital input contacts. The first contact is used as night offset input, the second
contact as external alarm.
The above mentioned settings are made via the Internal Parameters.
To allow also other combinations between setpoints, sensor and relays, there is the Advanced
Programming. This mode is only advisable for advanced users.
