Software issue Fan Coil Controller 3c
applies except where noted to
FCUD3cn hardware ACT-DIN-RLY 0006/0001 iss G
ACT-DIN-TOP
FCT-DIN-RLY 0020/0001
FCUA3cn hardware ACT-DIN-AOP 0016/0001
All ACT-DIN hardware must be large memory, universal scaling
FCUB3cn hardware BLR-DIN-RLY 0004/0002
FCUF3cn hardware FCF-DIN-RLY 0023/0001
This is the first of an evolving range of Fan Coil
Controllers, the eventual aim is to have one set of generic Fan Coil code which will run
on any of the hardware platforms. This issue uses four separate files. The driver
configuration options allow a wide range of output possibilities. Automatic Fan Speed
control is provided for multi speed fan applications.
The configuration variable structures have been upgraded to also store the units of the
parameters. This now means that temperature parameters can be displayed in C or F on Zone
Controllers ZON3c1 onwards. These changes are required for the USA market.
The FCU controllers are registered to a Boiler Controller, this must be at least BLRxx3a7
(latest issue hardware 'C') or Floor Controller FLR3a1. In most respects the FCU
controller behaves in a similar manner to a Slave Zone Controller, it is registered as a
Zone. One major difference is that it does not have it's own Occupation times and so does
not do it's own Optimum Start. A Zone Controller is required to provide these facilities
for any number of FCUs.
In order to talk to FCU controllers with Doorway the SLT needs to be upgraded to issue 3a5
or later. It is possible to use the [#] addressing method (last service pin pressed) if
the SLT available is not 3a.
Zone controllers used with FCU's must be ZON3b1 or later running on latest large
memory hardware, earlier versions will not recognise FCU controllers for registration.
The FCU controller supports sensor fail SENF alarm, this is
raised if the Return Air sensor fails and the FCU is in a mode which requires the Return
Air temperature. The Input Mode can also be set up to generate an alarm for either a short
or open circuit on terminals 'temp a', see later.
Alarm mode and Alarm State config variables have been added to the config variable list.
Alarm mode 0 alarms ignored
1 alarms reported no other action
2 control output set to zero on alarm
3 STOP alarm recognised control set to zero
Alarm State determines which input state 0 or 1 is considered to be the alarm condition.
The registration procedure for all modes is the same as for
registering Slave Zones to a Master Zone. Put the Master Zone Controller into config then
register each FCU in turn. The zone will report SLVE 2 (for FCU 2, 3 for FCU 3 etc.) The
Master Zone will be set automatically to SPMD 3 when a Fan Coil is slaved to it, to
allow the Fan Coils to receive the Setpoint and Occupation information.
The FCUs are put into the same group as the Master Zone, any number of FCUs can be linked
to a single Master.
The Return air sensor must be fitted and the SPTY must be set
to 0 or 1.
Note the Occupation and Setpoint data is only updated every minute so be patient when
commissioning, operationally this is OK because the change will normally come from the
Optimum start routines which are checked every minute. If the setpoint is changed on the
Master Zone (with the knob) the new setpoint is sent straightaway.
Occupancy control SPTY 0
The AHU can be left to control from it's own setpoint but Occupancy is controlled from
a single Zone controller by registering the FCU to the Zone. The FCU will control to a
constant Return air setpoint regardless of the heating or cooling demands from the Zone.
If a supply air sensor is fitted then the off-coil temperature will be controlled within
the limits defined by MAXH, MINH, MAXC, MINC.
Setpoint supervision SPTY 1
This is the default mode of operation. The FCU(s) will control the return air (during
optimum start and occupation) to the setpoint defined by the Zone Controller.
The FCU Return Air setpoints can be individually adjusted using the SPTR setpoint trim
config variable to adjust for local conditions.
If a supply air sensor is fitted then the off-coil temperature will be controlled within
the limits defined by MAXH, MINH, MAXC, MINC.
The Return air sensor is not fitted. The mode must be set to
(SPTY) 2.
Supply Temperature scheduled to Heat and Cool demands from Zone SPTY 2
If a Supply Air sensor is fitted the Fan Coil will schedule the temperature of the
supply air (off coil) according to the Heat and Cool demands from the Zone Controller.
Remember that the Zone Controller will only provide cooling demands if it's setpoint
deadband SPDB is not set to zero.
The setpoint for the Supply Air control is calculated from the MAXH, MINH config limits
for heating demands and from the MAXC, MINC limits for cooling demands.
If there is no sensor fitted the Heat or Cool demand from the Zone will be used to
directly control the output stages, this mode is also used to 'slave a FCU' to another
FCU.
The supply sensor can be replaced by a switch which when made
will force the FCU to Occupied. On FCF or BLR boards the external connection is made to
'input a', thus retaining the use of the supply sensor.
This is achieved by adding an extra config variable input mode INMD. The following values
are supported.
0 normal operation input measures Off Coil temperature
1 Occupied is External AND normal occupation (window contact)
2 Occupied is External OR normal occupation
(outside normal hours)
3 Occupation controlled by external signal only
4 Input used as an external alarm, alarm state defined by ALST
If the switch is wired in series with a 10K resistor and a 10K potentiometer Occupied/ Non
occupied plus a 5 degree trim (operational only whilst occupied) is possible. The trim is
slightly non linear (the applied resistance is affected by the parallel resistance on the
board which helps linearise the thermistor when fitted, mechanical centre position of the
pot gives -0.7C) The zero point can be adjusted to give the correct (0 trim) by backing
off any error using the software trim SPTR. Suggest pot is marked Hotter/Colder or +/- !
A resistance between 0 and 20K ohm will be considered to be Occupied, non Occupied is
guaranteed for resistance values above 100K. The voltage generated by the pot will be
converted to a setpoint Trim only for control modes SPTY 0 or 1
The controller will automatically control fan speed, if the
multi-speed fan driver is used. If either the heating or cooling demand is greater than
90% for a period longer than FPRD (seconds/10 to match other periods) then the fan speed
will be incremented up to the next speed. If both the heating and cooling demand is less
than 10% then the Fan Speed is reduced after the same delay time. While occupied the
controller will maintain a minimum of Fan Speed 1.
Provision is made for the fan speed to be controlled from a network variable
(nviFanSpeed), from a (hotel style) zone controller for example, if this network variable
is non zero then this will override the automatic fan speed control.
This allows one 'master FCU' to provide the Return Air control
for a large space and to send its HeatOp and CoolOp outputs to one or more 'Slave FCU's'
The Master must be operating in mode SPTY 0 or 1, i.e. must be measuring and controlling
Return temperature.
The 'Slave' must be operating in mode SPTY 2. The registration process involves putting
the master into config mode and then pressing the registration button on all the 'Slave
FCU's'.
The Slaves are put into the same group as the Master FCU, any number of Slaves can be
linked to a single Master.
If a Slave FCU is subsequently linked to a Zone Controller the link to the Master AHU will
automatically be broken.
Any FCU can act as a source of setpoint (and occupancy)
information for a group of FCUs which are all controlling to their local Return Air
sensor.
This would be useful when one FCU has a local Trim Pot (or
Occupancy switch) and the same setpoint is required on other FCUs feeding the same area of
the building.
Put the 'master' into config and 'slave' the other FCUs. The Slave FCUs will receive the
mid point setpoint (C1 SPFC plus any external Trim) of the Master, local additional
trim can be applied to each FCU using SPTR. To maintain balance amongst the
FCUs the setpoint deadband SPDB should be the same in all units within the group.
In this way a Zone Controller can provide Setpoint and/or Occupancy information to a
'master FCU' within each separate space, these FCUs can have local User Adjustments (for
the cheapskates who won't buy Zone Controllers) or Occupancy overrides, these modified
conditions are then sent to all FCUs within the area.
There are no limits on the number of FCUs which can be slaved to a 'master FCU'. A Slave
FCU can also be a 'master' to a further group of FCUs, although this only makes sense if
these FCUs are operating in mode SPTY 2;either Off Coil only control or in Driver only
mode (no sensors fitted).
A new hardware driver has been written which allows almost any
relay output combination to be setup with configuration parameters. Instead of setting a
single TYPE parameter to define the driver setup six parameters have been made available
so that new combinations of output are possible. These have been placed in a new 'fixed
block' starting at config 150.
HTYP sets heating type 0 no heating relays
1 raise/lower valve (uses two relays)
` 2 sequence and time proportioning
3 sequence and fast TP (PERD set in seconds)
4 analogue level
5 4R FCT driver
HSTG sets number of relays 0 to 3 (6 for Boiler board derivatives)
(Note if the driver type is 4R FCT if stages is set to 1 then the output will time
proportion on the raise output, for R/L operation set stages to 2)
HPRD sets stroke time, fast TP period or min on/off time depending on driver type
seconds/10
CTYP sets cooling type 0 no cooling relays
1 raise/lower valve (uses two relays)
` 2 sequence and time proportioning
3 sequence and fast TP (PERD set in seconds)
4 analogue level
5 4R FCT driver
CSTG sets number of relays 0 to 3(6 for Boiler derivatives)
(Note if the driver type is 4R FCT if stages is set to 1 then the output will time
proportion on the raise output, for R/L operation set stages to 2)
CPRD sets stroke time, fast TP period or min on/off time depending on driver type
seconds/10
FTYP sets fan type 0 no fan relays
1 not used on this type
` 2 sequence and time proportioning
3 not used on this type
4 analogue level
5 not used on this type
6 single fan on last relay
7 multi_stage fan
FSTG sets number of relays 0 to 3
The sequence/ time proportioning driver type automatically puts on enough relays to match
the demand with the last relay in the sequence being time proportioned in line with the
unsatisfied demand.
For example assume two stages and 75% demand level
The first relay will be on, accounting for 50% of the demand, the second relay will time
proportion at a rate of 25% of unsatisfied demand as a percentage of the stage value (50%
per stage) which is 100*25/50 or 50%. A single stage will work like a standard time
proportioning output.
Example combinations with ACT-DIN-RLY (or ACT-DIN-TOP)
description |
HTYP |
HSTG |
CTYP |
CSTG |
FTYP |
FSTG |
dual time proportioning plus fan |
2 |
1 |
2 |
1 |
6 |
1 |
raise/lower heating plus fan |
1 |
2 |
0 |
0 |
6 |
1 |
raise/lower cooling plus fan |
0 |
0 |
1 |
2 |
6 |
1 |
TP heat and raise/lower cooling |
2 |
1 |
2 |
2 |
0 |
0 |
three stage reheat |
2 |
3 |
0 |
0 |
0 |
0 |
Fast TP for electric heating Slow TP for DX cooling plus fan |
3 |
1 |
2 |
1 |
6 |
1 |
Fast TP heating, two channels in sequence plus fan |
3 |
2 |
0 |
0 |
6 |
1 |
The relays are allocated in the order Heat, Cool, Fan if the definition calls for more
relays than are available then later relays will be ignored. Note Driver type 1, raise
lower uses two relays even if the stages value is set to 1.
The default periods are raise/lower xTYP 1 xPRD 18 (180 seconds)
sequence xTYP 2 xPRD 6 (60 seconds)
seq fast TP xTYP 3 xPRD 10 (10 seconds)
Driver type 6 Single Fan
This uses the last available relay to drive the fan. This allows the position of the
fan wiring to be the same regardless of which relays are used for the heat and cool
drivers. This output can also be used to control a pump.
Driver type 7 Multi-Speed Fan
This will split the 0-100% demand for Fan Speed into 1,2 or 3 speeds depending upon
how many Fan Stages (FSTG) are specified. This is different from a sequenced driver
because only one relay is energised for each selected speed. When the speed is reduced all
the relays go off for at least 10 seconds to allow the motor to slow down.
Most of the above driver options are also possible when using
the Analogue output board.
Driver type 1 raise lower
One analogue channel is allocated to the driver and the output voltage is set to drive
a Sontay IO-RM2 Raise/Lower relay module. The full raise lower driver is used within the
SeaChange controller allowing the same set-up routines as provides on a ACT-DIN-RLY board.
The number of stages needs to be set to 1.
Driver type 2 sequence driver
One analogue channel is allocated to the driver, the number of stages in the sequence
is set with HSTG or CSTG a maximum of eight stages for each driver is supported. The
analogue voltage is will change in steps to match the demand from the sequence driver.
Minimum on time, minimum off time are set in the normal manner. The last stage will time
proportion in line with the remaining unsatisfied demand. If only one stage is set then
the output will time proportion. The Analogue output can be used to drive sequence of
relays (Sontay), a single relay module or a d.c. input solid state relay.
Note the Fan type FTYP can be set to 2 (FSTG 1) so that a heating only or cooling only
application plus fan can be accommodated using the ACT-DIN-AOP board.
Driver type 3 Fast TP
This acts as for type 2 above but the time proportioning period is set with xPRD. The
analogue output can be used to drive a solid state relay which accepts a dc input.
Driver type 4 Analogue level
This outputs a continuous analogue level proportional to the driver demand when the
number of stages is set to 1.If the number of stages is set to 2, then the two analogue
outputs are used in sequence, analogue channel 1 handles 0-50% of the demand and channel 2
handles 50-100%.
These have been changed to a new more flexible approach. A
single parameter for each driver type is provided which sets up the on delay or run on
time for the fan or pump.
HDLY
Typically negative values will be used for wet batteries to provide start up protection
against frost and positive (run on-) values would be used with electric heating batteries.
The same features are available for cooling using CDLY.
The selection of OCC or OSS is now made by setting OCCO to 1 on controllers where the
control is only required when the building is in occupation. The default is for control
during OSS and OCC.
This is defined with a config parameter FRPT and it defines
the controllers action when it receives a 'frost alarm' from the boiler controller.
There are three plots setup as normal on the first three
'sensors'.
Plot 1 Supply air temperature
Plot 2 Return Air temperature
Plot 3 Heat/cool output -100 to +100 (negative for cooling)
The plot routine has been enhanced and the plotting period is now selectable. The period
parameter matches Doorway (and TREND) and is as follows
1 Every 15 minutes
2 Once per day at 0100
3 Every minute
4 Every hour on the hour
It is recommended that period type 1 is generally not used except while commissioning
since frequent plot re-scaling (every 90 minutes) will eventually wear out the EEPROM
memory.
The plots are now automatically re-scaled within the controller to achieve the best
resolution for the data recorded. This happens at the end of every 96 readings when new
maximum and minimum settings are calculated and also if a new value is outside the current
range settings.
These new features will be introduced on all issue 3 products as the new code is fully
released.
Will support registration of up to 8 Acuators, Acuator
Drivers, Pump ChangeOvers just like a regular Zone. This is not supported in version 3ax
0006 issue D boards due to lake of memory.
Fan Coil Controllers are addressed with [Zn] where n is the
Fan Coil Zone number 1-200. [Fn] is also supported.
Sub modules are addressed as follows
Actuators [Z1Am] m=1 to 8
Item codes follow the normal conventions