Feature Notes
Actuator Submodule with 3 x Triac Outputs (3T version) with 2 x 0-10V DC Outputs (AOP version)
ACT / DIN / 3T / ... ACT / DIN / AOP / ...
Main Features Controls Actuators and Staged Plant directly or with additional modules Fast Time Proportioning control of Electric Heating Works with or without Local Temperature Feedback Heating/Cooling or Heat + Time Switch or Cool + Time Switch operation

Summary Features

General

The SeaChange Actuator modules are Submodules, which can be used to extend the control capabilities of other SeaChange Modules. They can be used in conjunction with Zone Controllers, for instance, to control Zone valves or Electric Convector Heaters, or in conjunction with AHU and Secondary Circuit Controllers, to control modulating control valves.

Configuration parameters can be set to allow operation to match the plant control requirements. A full table of configuration and monitoring parameters is detailed later in this data sheet.

A table of available product versions is shown on the last page.

Operation

Actuator Submodules are driven by Control Demand signals from the module that they are registered to.

Different Driver Typesmay be selected to give Time-based control or Demand-based control in various combinations.

Demand-based control

Can be used to operate plant based on heating or cooling demands. The output drivers may be single stage (using Time Proportioning), Raise/Lower or Multi-stage, using the triac output versions. Analogue actuators may be driven using the 0-10Vdc output versions.

Time-based control

Can be used to operate plant which must run depending on occupation times only. The output drivers may be configured to run during Occupancy only, or during Occupancy and Optimum Start.

Temperature feedback.

Actuator Submodules will work with or without local temperature feedback.

If a temperature sensor is fitted, control is Closed Loop using the Control Demand from the parent module to calculate a setpoint for the Actuator Submodule. The overall scheme becomes Cascade Control.
If no temperature sensor is fitted, control is Open Loop with the output being proportional to the Control Demand from the parent module.

Office Churn

Office layouts often change during the lifetime of a building; sometimes this “churn” results in changes to the services which feed each zone. Actuator Submodules cope well with additional Zones, or Zone Controllers having to work with different zone valves as offices “churn” over time because the link between a Zone Controller and its Actuator Submodule may be deleted and re-instated easily, see Registration section.

Different Output Driver types can be used for different types of valve; Raise/Lower, Time Proportioning and Staged Drivers are available. The accompanying pump or fan can be switched using the Occupation Switch output C.

Triac outputs can be used for Fast Time Proportioning, allowing low cost proportional control of electric heating loads using external Solid State Relays.

An Analogue Output variant can control a 0 -10Vdc valve and switched loads such as a fan or pump via an external relay module.

Description of Features

Demand Control

The Actuator Submodule has no internal Occupation Time Schedules. Its operation is determined only by a Control Demand signal from the parent module it has been registered to.

The Control Demand interconnect signal from the parent module carries both the control loop demand output level and the parent module occupancy state.

Control based on Time only

Single Extract Fan controlled by Actuator submodule registered to AHU controller using the Occupation Switch output. Occupancy status information is encoded within the Control Demand interconnect. Choose a variant with Occupation Switch output e.g. ACT / DIN / 3T / 101

The Actuator Submodule will operate based on the occupancy times of the parent module including Optimum Start and Stop. The Optimum Start signal may be disabled by setting OCCO = 1; this means that the fan will remain off until the start of Occupancy.

Control based on Demand

Multi Stage Fans controlled by Actuator submodule registered to AHU controller using AHU Heating Demand. Choose a variant with sequenced outputs for heating e.g. ACT / DIN / 3T /109

The Actuator Submodule can be driven from the heating demand of the AHU controller.

Temperature Sensors and Inputs

Depending on the application, one or more sensors can be used for temperature control. The control temperature sensor is connected to input ‘temp b’ on terminals 5 and 6. The optional input ‘temp a’ on terminals 3 and 4 can either be used for an additional temperature sensor or alternatively a VFC input. The behaviour of the two inputs are configured by parameters SACT and INMD.

Two Temperature Sensors

Control Sensor and external Control Status input

Control Sensor and external Alarm Monitor input

Temperature Control

Actuator Submodules will work with or without local temperature feedback.

If no optional temperature sensor is fitted, the Actuator Submodule will interpret the Control Demand from its parent module (e.g. a Zone Controller) as a proportional output signal (e.g. a Valve Position). This is called Open-Loop control.

If an optional temperature sensor is fitted, the Actuator Submodule will automatically convert the Control Demand signal into a setpoint (e.g. Desired Supply Air Temperature) and control at the Actuator Submodule becomes Closed-Loop. The overall control scheme becomes Cascade Control, with the output from the Zone Controller’s control loop forming the setpoint for
the Actuator Submodule.

Operation with sensor fitted

The local temperature setpoints used by the Actuator Submodule may be set by the parameters MINH and MAXH for the heating setpoint (scaling from 0% to +100% demand), and MAXC and MINC for the cooling setpoint (scaling from 0% to -100% demand).

Advanced feature:The demand range over which the setpoint is scaled can be modified using the driver rescale parameters, this is useful when there are multiple sources of heat which need to be scheduled across the demand range. For example if the controller is controlling undefloor heating and there is also heat supplied by a Fan Coil heater the underfloor can be activated for the first 50% of demand by setting HRMN=0:HRMX = 50 the setpoint will then change from MINH at 0% demand to MAXH at 50% demand. The Fan Coil would be controlled on another actuator with scaling parameters set to HRMN=50:HRMX=100. If the controller is changed to open loop either by removing the sensor or changing CMDE then the rescale is applied to the driver demands.

The parameter CMDE = 1 enables a sensor connected to ‘input b’ to become the primary control sensor. The setting of CMDE = 2 can be used to change the control action to on/off control, where the heating or cooling output from the Actuator Submodule will be 100% when the controller is Occupied. In this mode, the sensor inputs are used for monitoring or alarm input only.

Operation with no sensor fitted

If no sensor is fitted (or the sensor is disconnected) the Controller will effectively bypass its control loop, and the Zone Demand will be used to drive the valve directly (thus if the Zone Demand is 70%, the valve will be driven to 70% open). This is called Open Loop control.

Sometimes, Open Loop operation is required but the sensor is needed for monitoring (for instance, if the Actuator Submodule was being used to enable a device with its own temperature controls, then the Controller’s own control loop would need to be disabled). In these cases, setting parameter CMDE = 0 will disable the control loop, allowing Open Loop operation, whilst leaving the sensor connected for monitoring purposes.

Pump Time Interlock Settings

The pump or fan can also be set to delay its start after the heating/cooling outputs have started, or to run on after they have shut down, using the configuration
parameters HDLY and CDLY. A negative value will start the pump the defined number of minutes after the heating/cooling drivers have been enabled; a positive value will cause the pump to run on after the heating/cooling drivers shut down.

Multiple Staged Fan Speed Control

Where delays are required when switching between stages of fan speed, the parameter FPRD can be set to a minimum time between switching stages

Frost Protection

The Actuator Submodule can be made aware of the Frost protection status of the Boiler controller. If the Boiler controller is in Frost Protect this is communicated to the Actuator Submodule which will open the heating valve to 50% (to primary coils and bypass) and run the pump if desired, as set by the parameter FRPT.

Two pipe Heat Pump Mode

The Actutor Submodule can control a valve which is used for both heating and cooling as part of a 'TWO PIPE' system. The temperature of the circulating medium, usually water, is received as the flow temperature from a Heat Pump controller or secondary controller(version 4d or later). The parameter TWOP is set to 1 and the controller will only allow heating if the flow temperature is above 20degC and only allow cooling if it is below 20degC. Since the same valve is used for both heating and cooling then the driver needs to be set to redirect the cooling demands to the heating driver, set the same driver type for both heating and cooling but only set the stages for the heating driver.

Note- this feature is available on a special version of ACT sub module (available on request)

Window Mode

When the Actuator controller is controlling the opening of a window using a Raise/Lower driver, then the parameter WMDE Window Mode should be set. The Raise Lower driver automatically tries to re-establish an accurate position value by repeatadly driving to the end stop if the position is demanded is withing 5% of maximum or minimum position, it also checks it's position by driving to the nearest end stop and re-positioning itself if the end stop has not been reached during normal use. This operation is very good if the driver is controlling a valve but can be disconcerting if the driver is used to control a window, or opening roof. Setting Window Mode removes these features, when set the stroke time of the driver should be set to a period slightly longer than the actual stroke time, this will ensure that the window fully opens or fully closes.

Alarm Handling

The Actuator Submodule may be set to ignore alarm conditions, report them to a SeaChange Doorway Supervisor (either locally connected to the system, or via an autodialling modem), or to both report alarms and take some control action. The ALRM parameter is used to select the desired Alarm Mode. The Actuator Submodule generates an alarm if the sensor fails and also if the external alarm input is used. The sense of the alarm input can be set by parameter ALST.

The Actuator Submodule may be set to respond to the STOP System Stop Alarm which is generated by another Controller; this can be used to shut down the entire control system, or parts of it, if a particularly critical event occurs. See Boiler Controller datasheets B1 or B2 for more details about the System Stop Alarm.

Alarm codes as they appear at Doorway Supervisor and InSite tool:

Local Indication of Alarms

Alarms are indicated by red flashing of the Temperature Indicator (Thermometer) LED, if the alarm results in a control action (e.g. shutting down the pump/valve). If ALRM is set to 0 (ignore alarms) or 1 (report alarms to supervisor only) then no control action will be taken, and the thermometer LED will not flash.

Commissioning

Setup Mode : Timing Characteristics of Output Channels

It is possible to set the stroke time (for Raise/ Lower type Actuators) and the minimum on/off time (for Time Proportion type Actuators) using pushbuttons.

Raise/Lower Types - Setting Stroke Time

1. Hold down Select until Temp lamp flashes
   Temperature indicator will flash red at one second intervals.
   Release select button; output B will energise to close valve.

2. When valve is closed press Select
   Temperature indicator will flash green and output A will energise to open valve. The controller is now measuring the stroke time.

3. When the valve is open press Select
   Flashing will stop and stroke time is now set and stored in non-volatile memory. This time will be retained until the procedure is repeated.
   

Note: if a Stroke Time of less than 30 secs is set using pushbuttons then the setup process is aborted. Temp indicator flashes amber rapidly for 5 secs indicating an invalid period. This allows checking of wiring without affecting Stroke Time setup. Stroke Times less than 30 secs can be entered manually via Zone Controller or InSite tool.

TP Types - Setting Minimum Time On/Off

1. Hold down Select until Temp lamp flashes
   Temperature indicator will flash green at one second intervals and relay A will energise.
   Release select button.

2. When minimum on/off time has elapsed, press select
   Flashing will stop and this time will be set and stored in non-volatile memory. This time will be retained until the procedure is repeated.
   Note that the full TP period will be 10 times this value.

The times can also be viewed and changed using parameters HPRD (heating) and CPRD (cooling).

Manual Override

Allows the outputs to be exercised during commissioning and maintenance activities. Holding the override button pressed until the Status Lamp flashes green will cause the controller to be switched from automatic control to Override Mode. Subsequent pressings of the manual override button will cycle through the available Override modes.

1. Hold down Override until Status lamp flashes
   Controller changes to Override Mode and becomes Occupied, controlling to current Occupied Setpoint.

2. Press Override again
   Controller changes to Manual Mode and output is set to 100% heating.
   Temperature lamp shows red.

3. Press Override again
   Controller changes to Manual Mode and output is set to 100% cooling.
   Temperature lamp shows amber.

4. Press Override again
   Controller cancels Manual Override and reverts to automatic control.

As this feature does not time out, care should be exercised to ensure the module is returned to the automatic mode on completion of the commissioning or maintenance activities.

Occupancy Override can also be achieved via Doorway and InSite; using AUTO and OVRD monitoring parameters. The status lamp indication shows a different sequence.

Override from Off to ON : Status lamp flashes long ON, short Off
Override from ON to Off : Status lamp flashes long Off, short ON
See our ‘Design Guide’ publication for details of the Override features.

Registration

Registration is the simple process by which logical connections are made between Controllers in a SeaChange system; it is done during commissioning and involves pressing buttons on the Controllers in a specific sequence.

For further details of the registration process, see our ‘Design Guide’ publication.

Address Allocation and System Housekeeping

Like all SeaChange Controllers, the Actuator Submodule must be registered with other modules in order to create a working system. During the Registration procedure, the address of each Controller is allocated by the module that contains System Housekeeping. Check that you have an appropriate System Housekeeping Module; see our ‘Design Guide’ publication.

Interconnects

The Actuator Submodule will receive Control Demand signals from other modules to determine when it operates. (see Demand Control).

See our ‘Design Guide’ publication for details of how to create interconnects.

Options and Product Codes

Actuator Submodule

ACT / DIN / 3T / [driver option]

Driver options

ACT / DIN / AOP / [driver option]

Driver options

* using RLY/DIN/10V/6A SeaChange relay module

SC Controls Ltd

PO Box313
Wadhurst
East Sussex
TN5 6JL

phone 08707 606040
fax 08707 606041
e-mail seachange@sccontrols.co.uk
http:// www.seachange.co.uk