DREHMO-Matic C Characteristic Features
Characteristics of Matic C
The Matic C control unit is located within the actuator housing on top of the countergear unit. Several advantages derive from this compact design:
- Easy access to any component of the control unit
- No secondary housing necessary, consequently no additional sealing
- The complete control unit can be hinged up (for full access) for commissioning and programming.
Electrical interfaces to DCS:
- electrical power supply (motor)
- digital command inputs
- digital signal outputs
- auxiliary voltage supply
Optional:
- external power supply for Matic C control unit
- analog position transmitter
- analog torque transmitter (for measurement of the characteristic torque curve of the valve)
- analog positioner (analog input)
- electronic torque and position sensor
- simplification of commissioning by LEARN function
- integrated BUS interfaces (either integrated at control unit or build in extended compact plug connector housing):
Profibus-DP
Profibus-FMS
Interbus-S
Auxiliary supply voltage
If there is no external control voltage available, the customer can use the internal 24 V / 30 mA auxiliary voltage to supply the digital command inputs (OPEN/STOP/CLOSE).
Transformer of the control unit
Easy to adapt to several main supply voltages (=voltage of motor).
Primary voltages: 380, 400, 415, 460, 480, 500 V, +10% / -15%, 50 or 60 Hz AC
Other voltages on request.
Secondary voltage: 24 V AC (reversing contactors) and 24 V DC (control unit)
The setting of the primary voltage is done at the factory according to the attached wiring diagram and according to the imprinted value on the transformer.
Phase correction
Independently to the connection of the 3 phase AC supply voltage, the direction of rotation of the output will always be correct, e.g. damages of the valve during commissioning can not occur, even if the supply voltage is connected to the actuator incorrectly.
Commissioning device
For commissioning there are 3 keys (OPEN/CLOSE and LEARN) provided to the control unit. By means of these keys, the actuator can be driven manually to any position. If supplied with mechanical limit switches, the switches could be adjusted to these position. If supplied with electronic position sensor, the current position could be defined as final position by pressing the LEARN key with the OPEN or CLOSE key simultaneously; after this operation, the final position is stored permanent at the control unit thus no mechanical setting necessary.
Power unit
Standard supply with two electrically and mechanicaly interlocked reversing contactors.
Type 1: Motors up to 1,75 kW
Type 2: Motors 1,75 kW and more
Option: Solid State Relay (ELR)
(also see "Additional equipment")
Space heater
To avoid condensation inside the control unit housing (=switches and hardware of the control unit), a space heater is installed at the control unit.
Option on request: Dead stop heater with external power supply.
Commands
Digital commands (24 V DC) are transmitted to the control logic voltage-separated by using coupling relay.
Mode 1: Commands OPEN - STOP - CLOSE (permanent command signals during travel)
Mode 2: Commands OPEN - CLOSE (inching duty) and AUTOMATIC (positioner, only DM C 005). Both modes are programmable at the control unit.
Control voltage: 24 V DC (-10% / +30%)
Control current: Approx. 10 mA
Digital indication signals
The digital output signals are transmitted to the PLC / control room by potential free relay contacts.
Voltage: 24 V...230 V, AC or DC.
Current: 400 mA max.
Contact material: Gold plated silver contacts
To protect the gold coating, the maximum load of the contacts must not exceed 5 VA.
Signals:
- final position OPEN
- final position CLOSED
- collective failure (containing motor temperature, torque failure and loss of voltage)
- selector switch of local control in position LOCAL
- selector switch of local control in position REMOTE
- torque failure during OPENING
- torque failure during CLOSING
- running indication OPENING
- running indication CLOSING
(running indications flashing or permanent signals, programmable via DIP switch)
Version DM C 004: Signals for two additional intermediate positions
All versions: Additional indication signals / special signals on request.
Integrated local control station
Valve actuators DREHMO Matic C are supplied as standard with a local control unit operated by two lever switches. Therefore the DREHMO actuator can be operated nearby the valve, which is an advantage especially during commissioning or in case of failure of the superior process control. The selector switch LOCAL - 0 - REMOTE is padlockable in any position by a usual padlock. Locking systems on request.
Option: Electrical interlocking of the local control station by remote command
(see "Additional equipment").
Functions of the local control station:
- Selector switch in position LOCAL
DREHMO actuator can be operated by control switch OPEN - STOP - CLOSE - Selector switch in position 0
DREHMO actuator can be operated neither via remote commands, nor via control switch of the local control. - Selector switch in position REMOTE
DREHMO actuator can be operated by remote commands only.
Integrated start-up device
When starting up the actuator the first time, several devices, like torque and limit switches, position transducer or other analog signals have to be adjusted or set inside of the control unit housing. To facilitate this procedure, a start-up device, consisting of three keys is build onto one of the circuit cards. With this keys, the DREHMO actuator can be operated even if the control unit cover with its local control switches is removed.
Start up with LEARN function
When choosing electronic sensors for travel and torque measurement in connection with a electronic display for torque and position indication, the function of the selector switch LOCAL - 0 - REMOTE is extended to START UP - LOCAL - 0 - REMOTE. With this enhanced function, the settings of the torque and travel limits can be carried out without opening the housing of the control unit. For most easy and safe operation, the start up sequence is guided by the display.
Electronic position transducer
The electronic position transducer transforms the movement of the output-drive into a proportional 4-20 mA analog signal. The value detection is done by a non insulating plastic potentiometer, mounted on the basic plate of the counter gear unit. The movement of the output-drive causes a variation of resistance of the sensor. This resistance is transformed into a 4-20 mA signal by an amplifier. The position transducer is supplied by the control unit (4-wire-technique), the 4-20 mA signal is available at two wires
Maximum load: 500 Ohm.
Standard at version: DM C 003, DM C 005, optional for DM C 004.
Electronic position- and torque sensor
The mechanical torque- and limit switches could be replaced optional by integrated electronic analog sensors, which detect the position and torque values. The electronic position- and torque sensor is an assumption for further options like commissioning with LEARN function, electronic position indicator, and analog position- and torque signal (4-20 mA).
Intermediate position signals
For applications with the requirement of intermediate positions of the operated valve, DREHMO Matic C offers two intermediate position signals. Both positions can be adjusted independant from each other by a potentiometer at the control unit. When the adjusted position is reached, the signal is transmitted by a relay contact; the motor will not be switched off. Standard at version DM C 004 only. If the option "electronic position- and torque sensors" is choosen, the setting of the intermediate signals is also done by the LEARN function, display guided, without opening of the control unit.
Matic C TIMER
With the TIMER modul, the opening time of the valve can be decreased either over the full stroke or, alternatively, from a certain position on until the final position is reached. By means of a DIP switch, the operator can enable the TIMER either for closing or for opening direction of the actuator's output drive.
The individual adjustment of the timer is done by three potentiometers:
- P1: Pulse length (0,5 sec. to 30 sec.)
- P2: Pulse break (0,5 sec. to 30 sec.)
- P3: Start of timer (0% to 100% of the valve stroke)
Timer operation is active in the area between the limit position CLOSE (0 %) and the start of timer.
Timer with positioner:
When using the timer in combination with the positioner, a better performance of the whole control loop can be achived. Hence a more sensitive and precise operation of the valve to it's nominal position is practicable.
Programming switches (DIP)
To increase the adaptability of the DREHMO-Matic C, with regard to different applications and therefore to simplify the planning of the plant, several functions can be programmed by means of DIP switches at the control unit. The programming is done directly at the actuator, which is to change its functions of command or indication.
The following functions can be set:
- Travel commands contact holding mode or inching mode
- torque- or limit-related switch-off at the final positions OPEN and CLOSED
- Torque override out of the end positions to open jammed valves (independent of the adjusted torque)
- Variation of the LOCAL signal: LOCAL signal means either
selector switch in position LOCAL or
selector switch in position LOCAL or OFF - Running indication static or flashing
- Variation of the COLLECTIVE FAULT: COLLECTIVE FAULT signal means either
COLLECTIVE FAULT including TORQUE FAILURE
COLLECTIVE FAULT excluding TORQUE FAILURE
Integrated positioner
The nominal position of a valve for modulating duty is usually transmitted to the modulating actuator by means of a 4-20 mA analog signal of a superior process-controller (e.g. pressure, temperature, flow rate etc.). For this purpose, the signals of the process, for example pressure or flow rate, are transformed by the process-controller into an analog 4-20 mA signal, which represents the nominal position of the actuator.
Within the DREHMO-Matic C control unit, the positioner creates a travel command by comparing the current position of the output-drive (actuator-internal value detection) with the nominal position (analog command), until the deviation between those two values is less than 0.5 %...5 % (adjustable).
In case of a loss of the leading 4-20 mA command, a "fail safe position" can be programed by a DIP switch and adjusted by a potentiometer (any position from 0-100 % can be adjusted as "fail safe position"). If the nominal position is less than 1.8 % of the 4-20 mA range (0 % represents end position CLOSED), the DREHMO-Matic C actuator will automatically drive the valve to the end position CLOSED.
Therefore a torque related switch-off at end position CLOSED is possible even by means using the 4-20 mA command. The positioner is activated by a 24 V command at the "automatic" clamp of the terminal. In case that this command is 0 V, the actuator can be operated by the digital inputs OPEN and CLOSE (24 V). Inner resistance of the 4-20 mA positioner: 100 Ohm.
Positioner is standard for version DM C 005.
DREHMO-Matic C PLC-system
Actuators for control application
Closed Loop actuator with fieldbus
