Main Features For use primarily with Underfloor Heating Manifolds Provides individual control of up to 3 individual zone valves/pumps Each zone channel can be associated to its own independent Zone Controller

Description of Features

The Multi Channel Controller is a derivative of the Secondary Circuit Controllers.

Initially only available in Heating version (with Cooling versions to follow) for control of Underfloor heating solenoids. Two or three outputs can be driven independantly from Zone demands. Demand collation still available and demands can be passed on to other secondary controllers. Weather compensation and local temperature control is not available.

Functional description

This controller provides control of solenoids or pumps on an underfloor heating manifold. Each output is wired to a separate solenoid thus three circuits can be controlled by one controller. The room temperature control is provided by a Zone Controller for each room and the three Zone Controllers are registered to the Secondary Controller.

Linking Zones to Output channels

Knobs K3, K4 and K5 are used to set the zone number appropriate for each output channel, so if Knob 3 ZONA is set to 5 then the heating demand from Zone 5 is used to control the driver on channel A. The default driver setting is for Time proportioning driver with a minimum on time of 10 seconds.

Note the outputs will not become active unless the Controller is Occupied, this is determined by the highest Demand being greater than minimum demand MIND. External overides and OCDS could also be used to determine Occupancy as in a standard Secondary Circuit Controller.

If Knob 5 ZONC is set to zero then the third channel can be used for a Fan or Pump as in the standard product.

The sense of the Outputs can be reversed by setting configuration variable IVOP, this is useful if the solenoid valves being used are reverse acting. Note this feature ONLY operates if the driver type is set to 2 (Sequence and time proportioning)

CT setpoint

The configuration parameter SPTY setpoint type is retained to allow the CT setpoint to be calculated in the same way as for standard secondary controllers, the highest demand will be converted to a setpoint which will be passed on to the Boiler controller. Note the weather compensation setting is not available.

The secondary circuit can be controlled (by setting SPTY) as:-

The controller receives zone trim demands from zone controllers which are utilising it's heat output and these demands are used to modify the setpoint for the secondary circuit. The controller passes on it's demand to the Boiler Controller in the form of a CT setpoint. (This action may be modified by the setting of HTCT). This setpoint is 10 degrees above the setpoint for the secondary circuit but this offset may be varied with the LOSS config variable.

When there is insufficient demand from the zone controllers the controller operates with a frost or non occupied setpoint (10C). See later section Occupation State.

Demand Signaling

An extra configuration parameter has been introduced which selects whether the demand signaling is via % demand or Constant temperature setpoints. This is in line with similar changes made in Zone and DHW controllers. Since the CT temperature range already has setup parameters the parameter in the Secondary controller is only 0 or 1. HTCT (CTCT in cooling version) set to 1 will force the controller to send the demand as a CT setpoint.

The Secondary Controllers will now decode received Constant Temperature demands by converting them into a percentage demand and then prioritising this demand along with any other demands which are being received. This has been included so that the Controller still operates even if the sending controller has incorrectly been setup to send a Constant Temperature setpoint. This practice should be avoided wherever possible because the rescaling takes extra processing time and will limit the demand fan in which the controller can handle. HTCT setting in any controller should only be set if the target Controller is a Boiler and the Heat is being taken off the Primary of the Boiler.

Occupation State

The occupied or non-occupied state of the controller is determined by the settings of minimum demand MIND.

MIND minimum demand

The highest trim signal from the zones is compared with this value and if greater the Controller is put into occupied mode. Once occupied the trim signal from the zone must drop below half the MIND setting to select non-occupied

Frost Protection

When the controller is non-occupied then the Frost protection controls become active.

Frost Alarm from the Boiler

If this alarm is received and the FRPT parameter is set then the controller will open all active outputs to allow the water to circulate arround the underfloor circuits.

Frost Setpoint breached

The controller has a default frost setpoint of 10degC, if a temperature sensor(s) is fitted and it reads a lower temperature than the Frost setpoint and CMDE is non zero then the control outputs will become active and a demand signal will be sent to the Boiler. A maximum of two sensor are available so two of the circuits can be explicitely protected, if both are connected set SACT to lowest. In practice a single circuit can probably be taken as representative of all the circuits as far as frost protection is concerned.

Occupation Destination

The controller can send it's Occupancy state to any other module which supports receiving OCDS, at present that is AHU, DHW, and other HSC or CSC controllers. This enables the demand fan-in, with filtering if appropriate to be done on a secondary controller which then sets say a Fresh Air AHU to run. To avoid the inevitable confusion regarding whether a demand link or an OCDS link is being made this feature is restricted to manual setting of OCDS in the sending controller, the table sets out the rules for OCDS numbering. Secondary Controllers will OR the Occupancy signal which arrives via OCDS with the normal Occupancy calculation. If the OCDS signal is the only occupancy signal then the controller creates a 'simulated demand' of 100%

External Source for Occupation State

The controller retains the standard features but only overrides to OFF have any operational significance. For example a window contact or pump alarm could be used to force non-occupancy which would shut all the valves.

The Secondary controller now supports input mode which allows an external input to be used to provide an occupancy signal or an Alarm. The VFC is wired into 'temp a' (centre pair of terminals) and the configuration parameter INMD is set to between 1 and 5, see configuration table.

Input Mode set to 5 enables a Pump Fail Alarm

When input mode INMD 1 (AND function) is used the external input can be used to 'enable' normal control, when the input is shorted the controller responds to the heat demands received from other controllers, when the input is open circuit the controller shuts down. This could be linked to a flow fail signal or other similar interlock.

If the external source is to be the only occupation signal then ensure that no other devices are pointing to the Secondary Controller's Heat or Cool source.

Pump Alarm

If a single pump is being controlled by the Controller then the state of this pump can be monitored with a readback signal, by wiring a Flow switch or contactor auxilliary contact to 'input a'. Set input mode INMD to 5 to select the Pump Alarm. An alarm will be generated if the readback is not true within 30 seconds of the pump being started. The sense of the readback signal can be changed with Alarm State ALST, if ALST is 0 then a short circuit should be applied when the pump is running. Remember that Alarm Mode ALRM set to zero disables all alarms.

If switch Interlock Pump ILKP is set then if a pump fail is detected the control outputs will be shut down and will remain in this state until the next change of occupancy or until the override button is pressed. The error led will flash red to indicate that a shut down has occured.

Status Monitoring

The two inputs on the controller can be utilised for Status monitoring if they are not being used for Temperature Control or Occupancy control (see above). The State of the input can be read on Configuration parameter C180 for input a and C181 for input b. If using input b for monitoring make sure that the control loops are disabled by setting Control Mode CMDE to zero.

Registration

The Controller must be registered with a Boiler Controller, the first controller so registered is designated Heat Source 2 , (the boiler itself being heat source 1).

Zone Controllers (or AHUs and FCUs) are registered to the Secondary Circuit Controller(VT) by putting the Secondary Controller into Config mode and pressing the registration button on all zones which use heat (or cool for CSC versions) from this circuit. The VT controller will change the HTSC variable in the zone controllers to match it's heat source number. Note leave at least 10 seconds between the registration of each zone.

If the heat source number for the circuit is known and the zone controller has already been registered with the boiler, the same effect can be achieved by simply changing the HTSC config variable on the Zone controller to the appropriate heat source number.

Registration of the cooling CSC version is the same except the CLSC parameter is updated, the first controller registered is designated number 2.

Configuration changes this issue

Many changes have been made to the configuration parameters to allow for the multi Channel controller compared with the standard Secondary CIrcuit Controller. New knobs allow for allocating Zone Numbers to the channels, new sensors show the demands on each channel, and the weather compensation parameters have been removed.

IVOP InVert OutPut inverts the operation of the output triacs on all channels using driver type 2. This allows for reverse acting valves to be accomodated.

Alarm Mode ALRM has an extra state which alows the controller to be shut down only on STOP alarms.

Frost Protect FRPT has an additional state to allow for pump only frost operation.

Options and Product Codes

Multi Channel Controller

MCC / DIN / 3T / [driver option]

Driver options

ENER-G Controls

ENER-G House
Daniel Adamson Road
Salford
Manchester
M5 2DT

phone 0161 7457450
fax 0161 7457457

www.energ.com
www.seachange.co.uk
www.smartkontrols.co.uk