Main Features Controls 2 Boilers and associated plant Up to 8 Boilers in one sequence using Boiler Cascade Submodules Self adapting Weather Compensation System Housekeeping function option Boiler plant operates on demand from the building, not fixed time programme Automatic sequencing of Modulating Boilers efficient control of condensing boilers

Summary Features

General

The Boiler Controller is an Energy Provider Module in the SeaChange system; that means that it provides heat energy to Distributor Modules (perhaps controlling secondary circuits) or Consumer Modules (which are responsible for using the energy). It will only function when it receives Demand signals from these other modules; in this way, the plant will only run when it is needed, rather than on a timed basis as is common in conventional control schemes.

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.

Heating and DHW demand signals

The Boiler Controller will take the Consumer or Distributor Module with the highest demand as the basis for its Primary Control Temperature.
If no Domestic Hot Water or CT demands exists, the Boiler Primary Control Temperature setpoint will be based on the current setpoint of the local VT Circuit which is generated by Zone Controller demand (see Weather Compensation and Trim, later). It will be set to 5 degC above the current VT setpoint to allow the VT valve to remain under control.

If multiple demands are being received from other modules requiring Primary CT water (for instance, another VT circuit controlled by a Secondary Circuit Controller, or a Domestic Hot Water load) the Boiler Primary Control Temperature setpoint will automatically be raised to the correct value to satisfy the Module with the highest demand. Modules that require Primary (CT) water send their Demand signals in the form of a setpoint, which is high enough to account for Primary losses.

In this way, the Primary Circuit is controlled at the lowest possible temperature to satisfy all of the connected loads.

VT Circuit Temperature Control

The VT circuit will control to the Heating setpoint while any Zone Controller is demanding heat; when all Zones are satisfied, the setpoint will reduce to the FRST Frost Protection setpoint parameter and the pumps will turn off (unless the MIND Minimum Demand parameter is set to zero - see Pump Control and Demand later in this document). Thus the local VT Circuit controlled by the Boiler Controller will be run only when necessary, and then to the lowest possible temperature to satisfy all of the zones.

Description of Features

Occupation Control

The Boiler Controller does not have any time settings of its own, as it is entirely Demand Driven from heating demand signals generated by other controllers. The parameter MIND can be used to set a minimum level of demand that will bring the boilers on. At least one Zone Controller is required in the system to set Occupation Times for the building.

Boiler plant is enabled by Heat Demand interconnect from Zone Controller.

Flow & Return Temperature Control

The Boiler Controller is capable of several different methods of controlling Flow and Return Temperatures. All of them are based on the principle of controlling to the lowest possible water temperature in order to minimise circulation losses. The Controller decides which method to use depending on which sensors are connected to it. Best control is achieved using the Flow Temperature if only one sensor is used.

The parameter SACT may be used to force the Boiler Controller to use flow, return or an average of both temperatures. The default setting SACT = 1 will control using the flow sensor only.

Parameter MAXF is used to set the Maximum Primary Temperature control setpoint selected by SACT. MINR is used to set the Minimum Return Temperature control setpoint, which is important for protecting some boilers against back-end corrosion. In order to maintain the Minimum Return Temperature during morning start-up, the VT Valve will limit its opening to mix the cold return water from the VT circuit with the hotter primary water; this effect can be limited, or disabled altogether, using the VLIM parameter, see Boiler Back-End Protection section.

Boiler Primary Setpoint Calculation

The Boiler Controller will dynamically calculate its Primary Control Setpoint FLSP according to the demands received from all of the loads which the primary circuit is feeding.

Consider a typical system with 2 VT circuits, and a CT circuit feeding an AHU.

Boiler Controller controls 2 boilers and VT Zone 1.
Secondary Circuit Controller with temperature control and Changeover Submodule control VT Zone 2.
Secondary Circuit Controller with Pump Changeover controls CT circuit for AHU.

When Zone 1 is demanding heat (and all other devices are satisfied) the Boiler’s own Heating Setpoint VTSP calculation will determine the VT Setpoint for Zone 1’s circuit (see Weather Compensation and Trim section). Assuming there is no CT demand and that MINR is satisfied, the Primary Setpoint FLSP will be adapted from initially 5 Deg C above this Heating Setpoint VTSP in order to maintain valve position VTPN at 75%. The aim is to keep the VT valve within its control range. If the VTPN becomes 100%, then the boiler setpoint FLSP will eventually rise to MAXF.

If Zone 2 now demands heating, the Secondary Circuit Controller controlling Zone 2’s valve will calculate a Heating Setpoint for this circuit (see Secondary Circuit Controller Data Sheet M3) and will add on an amount (determined by the Secondary Circuit’s LOSS parameter) to produce a Constant Temperature Demand to the Boiler Controller, which will adjust its Primary Setpoint accordingly.

Finally, if the AHU is demanding heat, the Secondary Circuit Controller feeding it will send a CT Demand, and the Boiler Primary Setpoint will be elevated to the temperature needed by the AHU (probably 82 Deg C).

Thus the Boiler Controller minimises the Primary Control Temperature at all times (thereby reducing the primary heat losses to a minimum). This also means that all loads on a Boiler system need to be represented by a SeaChange module, see our ‘Design Guide’ publication for fuller details.

Control of 6 Boilers by using Boiler Controller for boilers 1,2 and Cascade Submodules for boilers 3, 4, 5, 6. BLRS is set to 6.

Weather Compensation and Trim

The Boiler Controller runs the Boiler Plant on the basis of demand signals that it receives from other SeaChange Controllers. For the heating circuit, the demand is received from one or more Zone Controllers, which provide Optimum Stop/Start control of the occupied space.

The Boiler Controller controls water temperature for the VT circuit according to a Weather Compensated setpoint; this is further modified by demand signals from the Zone Controllers to produce the Heating setpoint. Any Zone or Slave Zone Controllers which are registered to the Boiler Controller for the purposes of Heating Demand (i.e. their HTSC parameter is set to point to the Boiler Controller) and whose parameter HTCT is set to 0 will be used in the calculation.

Weather Compensation with Zone Trim and Adaption

Zone Controllers produce demand signals varying between -100% (full cooling) and +100% (full heating). The Boiler Controller adapts the Weather Compensation to “learn” the building’s characteristic by keeping the highest-demanding Zone device at a +50% demand level during occupancy.

If the demand level is above or below 50%, the Weather Compensated setpoint is modified by two effects in the Fuzzy Logic Control loop; the trim effect will rapidly raise or lower the setpoint to take care of short-term changes in load.

The adaptive effect will additionally raise or lower the setpoint if the “error” from the 50% level is sustained over a long period, which represents the control system “learning” the thermal characteristic of the building.

The effects of these adaptations can be limited; the maximum excursion from the Weather Compensated setpoint caused by these effects can be set on two Configuration Parameters: TRNG sets the maximum trim effect, and CRNG sets the maximum influence of the adaptive effect.

These setpoint calculations remain active when the Controller is in an Occupied state (see Occupation Control, earlier in this document). At all other times, it will control to its non-occupied setpoint, FRST.

It is possible to disable Zone Trim and Adaption completely by setting CRNG and TRNG to 0. See Weather Compensation without Zone Trim and Adaption section.

Other Features

MXVT is a limit to VT flow temperature, (useful for limiting the flow temperature in underfloor heating applications), and also defines the Weather Compensated setpoint at 0 Deg C Outside temperature.

FLAV defines the unadapted Weather Compensated setpoint at 10 Deg C outside temperature.

SMRT defines a summer cutoff temperature; when the outside temperature exceeds this value, the VT heating circuit will be inhibited (the primary circuit will be allowed to run for CT demands only).

MNVF Minimum VT Flow

Some Boiler installations do not have a Primary Boiler Flow circuit, the Boiler Flow is fed directly to the radiator or Heating (VT) circuit. In these cases if the VT valve closes while the Boilers are running the water flow through the Boiler can be shut off thus causing a rapid build up of temperature which can lead to Boiler shut down on the over temperature safety interlocks. This parameter allows a minimum valve opening to be maintained when ever the Boilers are running, regardless of heating demand. This prevents the Boiler tripping the HIgh temperature cut off. If the parameter is left at its default value of zero then the feature is disabled.

Boost Mode

When any of the participating Zones are more than 1.0 DegC below their setpoint, they will drive the Heating setpoint into a Boost condition; it will temporarily leave the Compensation Curve with its adaption, and be set to the maximum permissible temperature, MXVT. Only when all Zones are within 1.0 Deg C of their respective setpoints will the Heating setpoint return to the adapted Compensation curve. This is done in order to perform the fastest possible Optimum Start, and also to provide a predictable heat input to the Zone in order that the Zone Controller’s Optimum Start self-adaption will work properly.

Disabling Boost Mode may be necessary if none of the participating Zones are reading a representative temperature (for instance, a Hotel heating system where it is impractical to put sensing in all of the rooms, and a simple Weather Compensated scheme will suffice). In this case, ZBST may be adjusted to disable Boost. Be aware that doing this will almost certainly disrupt the Optimum Start abilities of the system. See also Weather Compensation without Zone Trim and Adaption.

Direct Compensation

If no VT sensor is fitted, the Controller will assume no VT Valve is present, and the heating setpoint will then apply to the Control Temperature in the Primary circuit instead of the VT Circuit. This is called Direct Compensation of the boilers.

Weather Compensation without Zone Trim and Adaption

In certain applications (for instance, a Hotel heating system where it is impractical to put sensing in all of the rooms) the Zone Controller(s) may not be located in positions which give adequate sensing of the whole controlled space. If the Boiler Controller was left with its default parameter settings, this would result in the boiler adapting its VT setpoint according to an inappropriate Zone Demand (see Zone Trim and Adaption), the Boiler Controller may stay in Boost Mode for longer than is necessary, and also the VT pump would stop when the Zone(s) were satisfied (see Pump Control and Demand).

In these circumstances, the Boiler Controller should be set to simplify the Weather Compensation by ignoring Zone Demands:

If these settings are made, the Zone Controller(s) still control the Optimum Start of the space, as well as Fabric Protection. Be aware, however, that during mid-season (i.e. when heating may not be required, but Outside Temperature has not risen above the SMRT setting) the VT pump will continue to run all day. To stop this happening, Occupancy Times in the Zone Controllers must be set to no occupation.

Boiler Sequencing and Duty Rotation

Multiple Boilers will be automatically rotated in their sequence on the basis of “longest running boiler goes off first”. This shares the plant duty between the boiler stages, and also gives good controllability under part load conditions. The sequence is reset if the boilers have all been off for more than 9 hours.

The HIL High/Low sequencing mode treats each pair of outputs as a single boiler, the first output being for Low Fire and the second being for High Fire. Up to four High/Low fire boilers can be sequenced by using cascade modules one for each extra boiler.

A Fixed sequence version of the Boiler Controller is available if required (see end of document for order code). This is useful where modular boilers must be brought on in a fixed sequence, such as when single and two stage boilers are mixed; or where a condensing boiler should always be first in the sequence.

The Boiler Controller can directly control 2 individual boilers or boiler stages. Additional stages can be added up to a maximum of 8 stages, by using Cascade Submodules. Use parameter BLRS to set the number of boilers to be controlled.

An All Remote feature allows all the boilers to be sequenced by Cascade Submodules, allowing the Boiler Controller status inputs to be used for general plant alarms, with each submodule monitoring the boilers.

To use the All Remote feature, set AREM = 1 in the Boiler Controller. In this mode, boiler outputs on the Boiler Controller are disabled, and only the outputs on the Cascade Submodules are enabled. The inputs on the Cascade Submodules are used for Boiler Status/Lockout and the Boiler Controller inputs for General Alarm inputs.

Modulating Boilers

From Boiler issue 4d1 a new method of controlling modulating boilers is introduced. This provides more efficient control of modulating condensing boilers with auto rotation. The new sequencer also handles mixed condensing and non condensing boilers more effectively. To use this new facility the Boiler Cascade modules must be issue 4b1 code or later, two types are available Analogue Output for modulating Boilers and Digital Output for fixed firing Boilers. The Analogue versions only control one boiler each, one output is the 0-10v burner demand and the other is a 0 or 10v output to enable the Boiler, an additional external relay will usually be needed to interface this enable to the boiler.

The new Cascade modules have configuration variables which allow each boiler to be designated as modulating and or condensing. The boiler sequence is modified such that boilers are started and stopped according to the following priority, within each class of boiler auto-rotation will be implemented to even out wear.

Condensing Boilers are most efficient at low fire when maximum flue gas condensation is possible, hence all condensing boilers are started first. The strategy is to run the minimum number of boilers needed to match the load multiple Modulating Condensing Boilers are run at the same burner level in parallel. Modulating Boilers will not run satisfactorily below about 20% of maximum output, this level can be set on the Driver parameter MNVO Minimum Variable Output so the controller can match the boilers to the load more accurately.

If only condensing Boilers are running then the Boiler Back-End Protection is disabled to allow maximum use of condensing mode..

Maximum Number in Parallel

A condensing Boiler running at minimum output with a low return water temperature can achieve 95% efficiency, at full output the efficiency will reduce to around 85% so a maximum efficiency strategy could be to run the boilers at minimum until they are all running then ramp them all up together thus maximising the time they spend in the condensing mode. The increased efficiency needs to be weighed against the increased wear and tear on the boilers. This 'maximum number in parallel' strategy can be selected by setting Driver Parameter MXPL to 1.

Modulating Non Condensing Boilers

Non-condensing Boilers operate at maximum efficiency at maximum output, for these Boilers it is preferable to only run one at part load and keep all the rest at maximum output. This can be achieved for up to 4 four modulating Boilers by using the Analog Cascade module, one for each Boiler, set the All remote configuration parameter and use the Hi-Lo sequence type. The Boiler which is in Lo fire mode will modulate, the other Boilers will run at Maximum output.

Pump Control and Demand

To maximise energy efficiency, normally the VT Pump will run only when a heating demand exists; when the Zones are satisfied, the Pump will stop and the boilers will control to the frost setting FRST instead of the weather compensated value. If, however, the Zone Controllers are not optimally located to give a comprehensive indication of demand from all areas, the MIND parameter can be set to zero. This will mean that the boilers and pumps will run, controlling to the heating setpoint (set by Weather Compensation with Zone Trim and Adaption), for the whole of the Occupation period. Alternatively, parameters in the Zone Controllers may be set to achieve a similar result while minimising the overheating effect that may otherwise occur (see Zone Controller Data Sheet for further details).

The Primary Pump is started as the first Boiler is fired and continues to run-on after the Boiler(s) have shut down. The BRON parameter sets the run-on time for the Primary Pump. If desired, the VT pump and Valve may be made to run-on for the same time by setting MODE parameter.

(Note this feature is only available in Boiler Controllers with Housekeeping; the MODE parameter in non-Housekeeping Boiler Controllers is fixed MODE=0).

Actuator Controllers registered to Zone Controllers will normally shut their valves during a boiler run on period, as boilers are not receiving Heat Demand in this condition. When MODE = 2 these Zone valves are rescaled or overridden. During normal operation the valve with highest demand is rescaled to 100% open , and others are opened proportionally (e.g. if highest demand is 60% and next highest is 30% then actuators will be driven respectively 100% and 50%.). During the run on period, these valves are all overridden to 100% unless they are cooling.

Twin Pump Sets

If either of the primary or secondary circuits have twin pumps sets, then they can be controlled by using Pump Changeover Submodules.

Note maximum limit of Submodules applies

The Boiler Controller can be interlocked with Pump Changeover Submodules such that failure of BOTH pumps causes the Boiler Controller to shut down its outputs. The Boiler Controller must be set to ALRM>0 and the PCO Submodule must be set to TYPE=1 or 2, ALRM=2, ACLR=1. Upon a dual pump failure the PCO Submodule goes into alarm and signals the Boiler Controller and its submodules to shut down. As the Boiler Controller shuts down it generates a PMPF Pump Failure Alarm. Meanwhile the originating PCO Submodule is also shut down and its alarms are cleared. The PMPF condition however remains latched in the Boiler Controller and neither it nor its submodules can be operated until the condition is cleared. Once the fault has been rectified the PMPF alarm can be cleared and the Boiler Controller and all its submodules can be returned to normal operation by pressing the override button on the Boiler Controller or setting ALRM=0.

DHW Priority

The DHWP parameter may be set to give priority to DHW where the plant is sized for Heating or DHW, but not both, or where a fast DHW recovery is required; if this is used, the VT circuit will be disabled until all DHW services are up to temperature. Note that if DHWP is set but CT demands come from other controllers (e.g. AHUs) then the VT valve shuts whenever a CT demand exists.

Maintenance mode

In Maintenance mode, the Boiler Controller simulates a 50% demand signal from Zone Controllers, so the heating will control to the Weather Compensated setpoint. This is useful for commissioning during the summer months, when no heating demand exists.

The Controller is put into Maintenance Mode by holding down the Override button until the status light flashes rapidly; the Controller will stay in this mode until the button is pressed again.

Submodules

The Boiler controller can have up to 4 Cascade or Actuator Submodules and 3 Pump Changeover Submodules registered to it (type / 001 for primary pumps or flue dilution fans, or type / 002 for VT pumps). The submodule limits are reduced to 2 Cascade or Actuator Submodules and 1 Pump Changeover submodule for the / NH / non-housekeeping versions of the Boiler controller.

Frost Protection

Frost Protection is arranged as a 3-Stage sequence, which operates from a Frost Protection setpoint relating to Outside Air Temperature.

Stage 1 is invoked if the Outside Temperature falls below the Frost Protection setpoint FRST. The Primary and VT Pumps will run for the first 10 minutes in every hour, with the VT circuit closed to the Boilers.

Stage 2 is invoked as the temperature in any of the water circuits falls to 5 DegC. The Primary and VT Pumps now run continuously. Stage 2 will only be seen if FRST is set below 5 Deg C.

Stage 3 is invoked if the temperature in any of the water circuits reaches the Frost Protection setpoint FRST. The Pumps will run, Boilers will now fire and the VT circuit will open until all water temperatures reach 30 DegC.

Disabling Frost Protection

Stages 1 and 2 Frost protection may be disabled; this may be useful in a Domestic installation, where the noise of pumps running during the night is intrusive, and pipework is all contained in occupied parts of the building, and is hence unlikely to freeze. The procedure is deliberately made complex, in order to avoid inadvertent use:

Access the FRST parameter using a Zone Controller (see our ‘Design Guide’ publication for details), and reduce it to its lowest allowable setting of 2°C. Now put the Boiler Controller into Maintenance Mode (see former section) and temporarily “short” the Outside Sensor connection using a wire shorting link. Refresh the FRST variable (by pressing Select on the Zone Controller); it will now display as 0°C, this value can now be “written” (i.e. pressing the Override button on the Zone Controller) to the Boiler Controller.

Take the Boiler Controller out of Maintenance Mode and remove the shorting link, confirm the FRST setting is 0°C, the variable is now fixed at 0°C and cannot be adjusted by normal methods. When frost protection is disabled, boilers will be brought on if the water temperature falls below 5 Deg C.

To re-enable frost protection, select the FRST parameter and put the Boiler Controller into Maintenance Mode. Press the Override button on the Zone Controller (to “write” the parameter to the Boiler Controller); the FRST parameter will default back to 3°C. Take the Boiler Controller out of Maintenance Mode, the 'FRST' variable can now be set as normal to any permissible value.

Fabric Protection

Fabric Protection is an independent process operating in Zone and Slave Zone Controllers, to protect the building fabric against damage due to condensation. If the temperature in the space falls below the Non-Occupied setpoint (usually set to 10 DegC) the Zone Controller will send a demand signal to the Boiler Controller, which will start the plant in the usual manner (see Zone Controller Data Sheet Z1).

Boiler Back-End Protection

It is important that water returning to the boilers is kept above a minimum temperature (unless the boiler is a Condensing Boiler). This is in order to prevent the boiler flue gases from condensing; if this happens, the resulting condensate mixes with the products of combustion, forming a corrosive liquid which will attack the boiler.
The parameter MINR may be set to control the Minimum Return Temperature. In steady state conditions, if the Return Temperature falls close to MINR, the Flow setpoint will be raised (thus overriding the setpoint generated by demand signals from other modules).

During start-up, the Return Temperature may be low, and elevating the Flow setpoint may not be sufficient to bring the Return Temperature to an acceptable value. If the hydraulics of the system will allow, the VT Valve may be overridden to the closed position (to the Secondary Circuit) thus allowing the primary water to return directly to the boilers, and hence meet the requirements of MINR. As the required Return Temperature is met, the VT Valve will be allowed to open gradually until steady state conditions are reached. The VT valve will be held at the VLIM setting when the return is 10 Deg C below MINR.

The amount by which the VT Valve is allowed to close can be limited by parameter VLIM. If VLIM is set to 100, the Back End Protection Override of the VT Valve is disabled. A setting of 50 will allow the valve to close to 50%, and a setting of 0 will allow the valve to close completely.

Summer/Winter Override

Configuration variable DMOR (Demand Override) allows 'input a' to be used to disable the demand on the boiler. When DMOP is set to 1 and status of 'input a is in the alarm condition, as defined by ALST (see below) all demands to the boiler will be disabled. Frost protection routines for the Boiler and its pipework will still operate however fabric protection as provided by the Zone Controllers will not operate. This feature is designed for use in schools where a TERM/HOLIDAY switch is required by the HVAC specification. It is strongly recommended that the Master Holiday feature in the Zone Controllers is utilised to achieve holiday settings since this allows local overrides when teachers need to do work during the holidays and protects the fabric of the building against low temperatures and condensationn damage.

This feature is only active when the Alarm Mode setting is NONE (0) or General Alarm (3), because the other modes use 'input a' for lockout or disable functions

Alarms

The Boiler Controller may be set to generate Alarms, which may be sent to a SeaChange Doorway Supervisor (either locally connected to the system, or via an autodialling modem). Alarms may be enabled by setting the ALRM parameter.

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

Danger of Freezing

This Alarm is generated when any of the connected water temperature sensors (Flow, Return or VT sensor) shows a reading below 5 Deg C; implying the Frost Protection strategy has failed.

Outside Sensor Failed

This Alarm is generated when either the locally wired thermistor sensor fails (to open or short circuit), or if a Networked Outside Sensor is used, the alarm will be sent if this device fails.

Frost Protection in Progress

This Alarm is generated when Frost Protection stages 2 or 3 are in action, running the pumps continuously.

Local Indication of Alarms

Alarms are indicated by red flashing of the Temperature Indicator (Thermometer) LED. STOP alarms are differentiated from other alarms by flashing the thermometer LED amber and red alternately.

External Alarm Inputs

The 2 external inputs ‘a’ and ‘b’ may be used for monitoring purposes only, alarm generation, or alarm generation with plant shutdown. Parameter ALRM is used to set the desired action, and ALST is used to set the sense of the inputs (i.e. whether a closing or opening contact generates an alarm).

System Housekeeping Functions

In a conventional Wet Heating environment, the Boiler Controller performs several important housekeeping functions for the rest of the system.

Firstly, it contains the real-time clock, which broadcasts time-of-day and day-of-week information to any modules that may need it. The clock may be set from any Zone Controller, and the time information is backed up by a Capacitor, which means that the correct time is retained for a minimum of 8 hours in the event of power failure (providing that power has been applied for at least 1 hour).

Secondly, it broadcasts Outside Temperature to any other modules that may need it; it acquires the temperature either from a sensor directly connected to its input terminals 15 and 16, or from a Networked Outside Temperature Sensor. In the absence of both sensors, it will transmit a default value of 0.1 DegC lower than the Frost Setpoint (FRST).

Thirdly, it performs an important role in the unique SeaChange Registration process; it is responsible for the automatic allocation of system addresses during registration. It also keeps track of all Registered Controllers, so that if one of them fails, a replacement will be automatically allocated with the address of the failed module. This automatic feature may prove troublesome when commissioning large systems, so it can be disabled using parameter RPLN. When Commissioning is complete, the automatic mode can be reinstated. For further details, see our ‘Design Guide’ publication.

Secondary Boilers - No Housekeeping

In systems having 2 or more independent sets of boilers, (e.g. Campus installations with multiple Boiler Houses) Boiler Controller versions / NH / with No Housekeeping must be used. These controllers are supplied with the System Housekeeping functions disabled, to avoid conflicts with the Boiler Controller versions / SH / with System Housekeeping. Thus, in a system with 3 independent boiler plants, we would use 1 Boiler Controller version / SH / with System Housekeeping, and 2 Boiler Controllers / NH / with No Housekeeping. Note that the Boiler Controller version / NH / with No Housekeeping can have a maximum of 2 Boiler Cascade or Actuator Submodules and 1 Pump Changeover Submodule registered to it, see Submodules section.

Multi-Domain Systems

Large systems may need to have their networks structured into more than one Domain. Boiler Controllers in a Multi-Domain system will require setting of the DOMN parameter, see our ‘Design Guide’ publication for details.

Commissioning

Setup Mode : Timing Characteristics of the VT Valve

It is possible to set the stroke time for the VT valve 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; VT valve close output will energise to close valve.

2. When valve is closed press Select
   Temperature indicator will flash green and VT valve open output 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 seconds is set using pushbuttons then the setup process is aborted. Temp indicator flashes amber rapidly for 5 seconds indicating an invalid period. This allows checking of wiring without affecting Stroke Time setup. Stroke Times less than 30 seconds can be entered manually via Zone Controller or InSite tool using parameter PERD.

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.

1. Hold down Override until Status lamp flashes
   Controller changes to Override Mode and simulates 50% Zone Demand, allowing boilers to control to Weather Compensated Setpoint.
   Useful for commissioning in summer months.

2. 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.

Hand Control

A new control mode has been added which allows Doorway to select manual HAND, this is activated by setting switch 5 HAND. The forces the controller to manual mode and the output of the VT loop is defined by the value on the config variable MANL. On this controller only 0 to 100% has significance because the Boiler controller only has heating. The Boiler sequencer will run the number of boilers needed to maintain the Flow temperature.

The process of selecting HAND and setting the manual level can be associated on the same point by using the following Doorway syntax.

[B1]W5(S)/hand/auto/12/10/C83(V) assumes the controller is Boiler 1

Clicking on the point allows selection of hand or auto and also the means to set C83 which is the manual level required.

InSite automates this process with it's 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

Boiler Controllers versions / SH / with System Housekeeping provide the System Housekeeping service for the whole SeaChange system. See our ‘Design Guide’ publication for a full explanation of this feature. The Boiler Controller keeps a Database containing the module addresses that it has allocated. Boiler Controllers with System Housekeeping are factory-set to address H1 (B1 also works with Doorway pages), and do not need to be registered to obtain an address. If the Register button is pressed, nothing will happen.

The maximum number of main modules that can be registered to a Boiler Controller with System Housekeeping are:

Address Class

Boiler Controller versions / NH / with No Housekeeping must be registered in the normal way to the SeaChange module that has System Housekeeping. The Boiler Controller with No Housekeeping will be allocated an ‘H’ class address by the System Housekeeper, see our ‘Design Guide’ publication.

Check that you have an appropriate System Housekeeping module, see our ‘Design Guide’ publication.

Interconnects

The Boiler controller must receive signals from a Zone Controller, or another Energy Consumer (e.g. Fan Coil Controller) or Distributor module (e.g. Secondary Circuit Controller). It may also send signals to other modules (e.g. a Pump Changeover submodule to control twin pump sets).

These Interconnects are put in place by Registration; again, see our ‘Design Guide’ publication.

Options and Product Codes

Boiler Controller Module

BLR / DIN / STD / [housekeeping] / [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.co.uk
www.seachange.co.uk
www.smartkontrols.co.uk