SCU224
Mounting
Connection
Application examples
Operation
49011100
*49011100*
SCU224
Troubleshooting
en-US/CA
Thank you for buying this product.
Read this manual carefully to get the best perfomance from this unit.
Please keep this manual carefully.
5443203 v1.0 02/2010
Manual
SCU224
Contents
General...................................................................... 2
Overview.................................................................... 3
1. Installation............................................................ 4
1.1Mounting.................................................................................4
1.2Electrical connection............................................................4
1.3Data communication/ Bus..................................................5
1.4Terminal allocation in the different system layouts.....6
System layout 1......................................................................6
System layout 2......................................................................8
System-specific functions................................................. 10
System layout 3....................................................................12
System-specific functions..................................................14
System layout 4....................................................................16
System layout 5....................................................................18
System layout 6................................................................... 20
System layout 7................................................................... 22
System layout 8....................................................................24
System-specific functions................................................. 26
System layout 9................................................................... 28
System layout 10................................................................ 30
2. Operation and function.................................... 32
2.1Push buttons....................................................................... 32
2.2System monitoring display............................................... 32
2.3Flashing codes......................................................................33
3. Commissioning.................................................. 34
4. Channel overview.............................................. 37
4.1Display channels..................................................................37
4.2Adjustment channels......................................................... 39
5. Troubleshooting................................................ 47
5.1Various:................................................................................. 48
6. Accessories......................................................... 50
Impressum............................................................... 52
General
Please pay attention to the following safety advice in order
to avoid danger and damage to people and property.
Subject to technical change. Errors excepted.
Description of symbols
WARNING!
Warnings are indicated with a
warning triangle!
They contain information on how
to avoid the danger described.
Signal words describe the danger that may occur, when it
is not avoided.
Warning means that injury, possibly life-threatening injury,
can occur.
Attention means that damage to the appliance can occur.
Note
Notes are indicated with an information
symbol.
ÎÎ Arrows indicate instruction steps that should be
carried out.
|2
Instructions:
Attention should be paid to
•• valid national and local standards and regulations
•• respective valid standards and directives
Equipment to be installed and used in accordance with
the rules of the National Electrical Code (NEC) or with
Canadian Electrical Code (CEC), Part I.
These instructions are exclusively addressed to authorized
skilled personnel.
•• Only qualified electricians should carry out installation
and maintenance work.
•• Initial installation should be carried out by qualified personnel
Information about the product
Proper usage
The solar controller is designed for use in solar thermal
and heating systems in compliance with the technical data
specified in these instructions.
Improper use excludes all liability claims.
Note
Strong electromagnetic fields can impair the
function of the controller.
ÎÎ Make sure the controller as well as the
system are not exposed to strong electromagnetic fields.
© Viessmann 5443203
Safety advice:
Please read the following information carefully before
installing and operating the controller. In this way damage
to the solar system caused by wrong installation will be
avoided. Please make sure that the mounting is adapted to
the characteristics of the building, that the local regulations
are respected and is conform with the technical rules.
SCU224
Overview
• System-monitoring-display
• Up to 4 Pt1000 temperature sensors
• 2 semiconductor relays for pump speed control
• 10 basic system layouts to choose from
• Energy metering
• VBus®
• Function control
• Thermostat function (time controlled)
• Control of the system by ServiceCenter software possible
!
• User-friendly operation
• Housing with outstanding design
• Extra-low power consumption
1 × accessory bag
1 × spare fuse T4A
2 × screws and wall plugs
4 × strain relief and screws
6.8"
172 mm
1 × SCU224
2.6"
66 mm
6.1"
155 mm
1.1"
28 mm
Included with the SCU224:
1 × manual
© Viessmann 5443203
Additionally enclosed in the full kit:
2 × sensor FKP6
2 × sensor FRP6
Technical data
Housing: plastic, PC-ABS and PMMA
Protection type: IP 20 / EN 60529
Ambient temp.:
32 ... 104 °F
[0 ... 40 °C]
Size:
6.8" × 4.3" × 1.9"
172 × 110 × 46 mm
Mounting: wall mounting, mounting
into patch-panels is possible
Display: System screen for system
visualization, 16-segment display, 7-segment display, 8 symbols for system
status and operating control lamp
0.4" / 11 mm
4.3"
110 mm
Operation: by 3 push buttons at the
front of the housing
Functions: Differential temperature
controller with optional add-on system
functions. Func­ti­on con­trol, operating
hours counter for solar pump, evacuated tube collector function, pump
speed control, thermostat function,
drainback and booster option, and
energy metering.
Inputs:
for 4 Pt1000 temperature sensors
Outputs: 2 semiconductor relays
0.5" / 13 mm
1.9" / 47 mm
Bus: VBus®
Power supply:
100 ... 240 V
~
Standby power consumption:
< 1W
Switching capacities:
R1: 1 (1) A 100 ... 240 V
~
(semiconductor relay)
R2: 1 (1) A 100 ... 240 V
~
(semiconductor relay)
3|
SCU224
1. Installation
1.1Mounting
WARNING! Electric shock!
Opening the housing will expose
live parts!
ÎÎ Switch off power supply and disconnect the device from power supply
before opening the housing!
display
push button
cover
cable conduits with strain
relief
fuse 4A
upper fastening
.
„
lower fastening
1.2Electrical connection
fuse
The unit must only be installed
•• in a dry interior location
•• in a non-hazardous location
•• away from electromagnetic fields
The controller must additionally be supplied from a doublepole switch with contact gap of at least 0.12".
Route sensor cables and power supply cables separately.
ÎÎ Unscrew the cross-head screw from the cover and
remove it along with the cover from the housing
ÎÎ Mark the upper fastening point on the wall and drill
ÎÎ Fasten the enclosed wall plug and screw leaving the
head protruding
ÎÎ Hang the housing from the upper fastening point and
mark the lower fastening point through the hole in the
terminal box (centers 5.1")
ÎÎ Drill and insert the lower wall plug
ÎÎ Fasten the housing to the wall with lower fastening
screw and tighten
ÎÎ Complete wiring connections in accordance with terminal allocations, see chap. 1.2 “Electrical connection”
ÎÎ Place the cover back onto the housing
ÎÎ Fasten the cover by means of the cross-head screw
ATTENTION! ESD damage!
Electrostatic discharge can lead to damage to electronic components!
ÎÎ Take care to discharge properly
before touching the inside of the
device. To do so, touch a grounded
surface such as a radiator or tap!
Note:
VBus®
sensor terminal
ground terminal
load terminals
The minimum pump speed must be set to 100 %
when auxiliary relays or valves are connected.
© Viessmann 5443203
power supply terminals
|4
SCU224
R1 1 (1) A (100 ... 240) V~
R2 1 (1) A (100 ... 240) V~
12 13 14
N R2 N R1 N L
15 16 17 18 19 20
Grounding and load terminals
Temp. Sensor
Pt1000
S1
1
2
3
S2
4
S3
5
6
S4
7
8
Sensor terminals S1 ... S4
1.3Data communication/ Bus
© Viessmann 5443203
VBus®
connection terminals
Connecting the device to the power supply must always be
the last step of the installation!
The power supply to the controller must be carried out via
an external power switch (last step!). The supply voltage
must be 100 ... 240 V~ (50 ... 60 Hz). Flexible cables must
be attached to the housing with the enclosed strain relief
and the corresponding screws.
The controller is equipped with two semiconductor relays, to which loads such as pumps, valves etc. can be
connected:
•• Relay 1
18 = conductor R1
17 = neutral conductor N
13 = ground conductor
•• Relay 2
16 = conductor R2
15 = neutral conductor N
14 = ground conductor
The power supply is to be carried out at the terminals:
19 = neutral conductor N
20 = conductor L
12 = ground terminal
The temperature sensors (S1 up to S4) are to be
connected to the following terminals with either polarity:
1 / 2 = Sensor 1 (e.g. Sensor collector 1)
3 / 4 = Sensor 2 (e.g. Sensor tank 1)
5 / 6 = Sensor 3 (e.g. Sensor tank top)
7 / 8 = Sensor 4 (e.g. Sensor return)
All Pt1000 temperature sensors are equipped with a
platinum measuring element in their tip. The electrical
resistance of the measuring element changes in relation
to the temperature (see table in chap. 5).
The difference between FKP and FRP type sensors only
lies in the cable insulation material. The insulation material
of FKP type sensor cables resists a higher temperature, so
that FKP type sensors should be used as collector sensors.
FRP type sensors are best used as reference sensors in
tanks or pipes.
The controller is equipped with a VBus® for data transfer
with and energy supply to external modules. The connection is carried out at the terminals marked “VBus” (either
polarity). One or more VBus® modules can be connected
via this data bus, such as
•• GA3 large display, SD3 smart display
•• DL2 datalogger
•• VBus® /USB or VBus® /LAN interface adapter
•• VBus® /PWM interface adapter
•• AM1 alarm module
•• WMZ calorimeter module
By means of a DL2 datalogger or an interface adapter,
the controller can be connected to a PC or a computer
network. With the ServiceCenter Software (RSC) the
controller measurements can be read out, processed and
visualized. The software allows easy function control of the
system. For the remote parametrisation of the controller, a
special software tool will be available for download, soon.
5|
SCU224
1.4Terminal allocation in the different system layouts
System layout 1
The controller calculates the temperature difference between collector sensor S1 and tank sensor S2. If the difference is larger than or identical to the adjusted switch-on
temperature difference (DT O), the solar pump will be
operated by relay 1, and the tank will be loaded until the
switch-off temperature difference (DT F) or the maximum
tank temperature (S MX) is reached.
Sensors S3 and S4 can optionally be connected for measurement purposes.
If energy metering (OHQM) is activated, sensor S4 has to
be connected as return sensor.
If the drainback option (ODB) is activated, relay 2 can be
used to operate a booster pump by activating the booster
function (OBST).
Note:
Viessmann Vitosol collectors cannot be used in
drainback systems.
Arr 1
S1
R1
S3
S4 / TR
Display Channels
Channel
Description
x*
INIT
ODB initialization active
x*
FLL
ODB filling time active
x*
STAB
ODB stabilization in progress
COL
x
Temperature collector
TST
x
Temperature tank
S3
x
Temperature sensor 3
S4
x
Temperature sensor 4
TR
x*
Temperature return sensor
n%
x
Pump speed R1
hP
x
Operating hours R1
hP1
x*
Operating hours R1 (if OBST is activated)
hP2
x*
Operating hours R2 (if OBST is activated)
kWh
x*
Heat quantity kWh
MWh
x*
Heat quantity MWh
TIME
x
Time
|6
Terminal
S1
S2
S3
S4
S4
R1
R1
R1
R2
-
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© Viessmann 5443203
S2
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT O
x
Switch-on temperature difference
DT F
x
Switch-off temperature difference
DT S
x
Nominal temperature difference
RIS
x
Rise control R1
nMN
x
Minimum pump speed
S MX
x
Maximum tank temperature
Emergency temperature collector
EM
x
Emergency temperature collector if ODB is activated:
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
OHQM
x
Option energy metering
FMAX
x*
Maximum flow
MEDT
x*
Antifreeze type
MED%
x*
Antifreeze concentration (only if MEDT = propylene or ethylene)
ODB
x
Drainback option
tDTO
x*
ODB switch-on condition - time period
tFLL
x*
ODB filling time
tSTB
x*
ODB stabilization time
OBST
s*
Option booster function
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
1
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
270 °F [130 °C]
200 °F [95 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
OFF
07:00
19:00
30 s
30 min
OFF
6.0 l
1
45 %
OFF
60 s
5.0 min
2.0 min
OFF
Auto
Auto
En
°C
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Legend:
© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
s*
System-specific channel, only available if the corresponding option is activated
7|
SCU224
System layout 2
The controller calculates the temperature difference between collector sensor S1 and tank sensor S2. If the difference is larger than or identical to the adjusted switch-on
temperature difference (DT O), the solar pump will be
operated by relay 1, and the tank will be loaded until the
switch-off temperature difference (DT F) or the maximum
tank temperature (S MX) is reached.
Heat exchange from tank 1 to tank 2 will be operated by
relay 2, if the temperature difference between sensors S3
and S4 is larger than or identical to the adjusted switch-on
temperature difference (DT3O), until the adjusted minimum
(MN3O) and maximum (MX3O) temperature thresholds of
the respective tanks are reached.
Arr 2
S1
Tank 2
Tank 1
R1
S3
S4
S2
Display Channels
Channel
Description
x*
INIT
ODB initialization active
x*
FLL
ODB filling time active
x*
STAB
ODB stabilization in progress
COL
x
Temperature collector
TST1
x
Temperature tank 1 bottom
TSTT
x
Temperature tank 1 at the top
TST2
x
Temperature tank 2 bottom
n1 %
x
Pump speed R1
n2 %
x
Pump speed R2
h P1
x
Operating hours R1
h P2
x
Operating hours R2
TIME
x
Time
|8
Terminal
S1
S2
S3
S4
R1
R2
R1
R2
-
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© Viessmann 5443203
R2
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT O
x
Switch-on temperature difference
DT F
x
Switch-off temperature difference
DT S
x
Nominal temperature difference
RIS
x
Rise control R1
n1MN
x
Minimum pump speed R1
S MX
x
Maximum tank temperature
n2MN
s
Minimum pump speed R2
Emergency temperature collector
EM
x
Emergency temperature collector if ODB is activated:
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
DT3O
s
Switch-on temperature difference 3
DT3F
s
Switch-off temperature difference 3
DT3S
s
Nominal temperature difference 3
RIS3
s
Rise control R2
MX3O
s
Switch-on treshold for maximum temperature
MX3F
s
Switch-off treshold for maximum temperature
MN3O
s
Switch-on treshold for minimum temperature
MN3F
s
Switch-off treshold for minimum temperature
ODB
x
Drainback option
tDTO
x*
ODB switch-on condition - time period
tFLL
x*
ODB filling time
tSTB
x*
ODB stabilization time
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
2
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
30 %
270 °F [130 °C]
200 °F [95 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
OFF
07:00
19:00
30 s
30 min
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
140.0 °F [60.0 °C]
136.0 °F [58.0 °C]
40.0 °F [5.0 °C]
50.0 °F [10.0 °C]
OFF
60 s
5.0 min
2.0 min
Auto
Auto
En
°C
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Legend:
© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
s
Channel is specifically available in this system layout
9|
SCU224
System-specific functions
The following adjustments are used for the specific function
in system layout 2.
∆T control for the heat exchange between 2 tanks
DT3O:
Switch-on temperature diff.
Adjustment range:2.0 ... 40.0°Ra
[1.0 ... 20.0 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 12.0°Ra
[6.0 K]
DT3F:
Switch-off temperature ­diff.
Adjustment range:1.0 ... 39.0°Ra
[0.5 ... 19.5 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 8.0°Ra
[4.0 K]
Pump speed control
DT3S:
Nominal temperature difference
Adjustment range:3.0 ... 60.0 °Ra
[1.5 ... 30.0 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 20.0 °Ra
[10.0 K]
RIS3:
Rise
Adjustment range:
2 ... 40 °Ra
[1 ... 20 K]
in steps of 2 °Ra [1 K]
Factory setting: 4 °Ra [2 K]
Reference sensors for this function are S3 and S4.
In system layout 2 the controller is equipped with an additional differential control for heat exchange between two
tanks. The basic differential function is adjusted using the
switch-on (DT3O) and switch-off (DT3F) temperature
differences.
When the temperature difference exceeds the switch-on
temperature difference, relay 2 switches on. If the temperature difference then falls below the adjusted switch-off
temperature difference, relay 2 switches off.
Note:
The switch-on temperature difference must be
at least 1 °Ra [0.5 K] higher than the switch-off
tempe­rature ­difference.
Note:
For pump speed control of the heat exchange
pump, the operation mode of relay 2 (MAN2)
must be set to Auto.
When the switch-on temperature difference is reached, the
pump is activated at full speed for 10 seconds.Then, the speed
is reduced to the minimum pump speed value (n2MN).
If the temperature difference reaches the adjusted nominal
temperature difference (DT3S), the pump speed increases by
one step (10 %). If the difference increases by the adjustable rise
value, the pump speed increases by 10 % respectively until the
maximum pump speed of 100 % is reached.The response of
the controller can be adapted via the parameter RIS3.
Note:
The nominal temperature difference must be
at least 1 °Ra [0.5 K] higher than the switch-on
tempe­rature ­difference.
Minimum pump speed
A relative minimum pump speed can be allocated to the
output R2 via the adjustment channel n2MN.
Note:
When loads which are not speed-controlled (e.g.
valves) are used, the value must be set to 100 % in
order to deactivate pump speed control.
© Viessmann 5443203
n2MN:
Pump speed control
Adjustment range:
30 ... 100
in steps of 5 %
Factory setting: 30
| 10
SCU224
Maximum temperature limitation
MX3O / MX3F:
Maximum temperature limitation
Adjustment range:
30.0 ... 200.0 °F
[0.0 ... 95.0 °C]
in steps of 1 °Ra [0.5 K]
Factory setting:
MX3O: 140.0 °F [60.0 °C]
MX3F: 136.0 °F [58.0 °C]
Minimum temperature limitation
MN3O / MN3F:
Minimum temperature limitation
Adjustment range:
30.0 ...190.0 °F
[0.0 ... 90.0 °C]
in steps of 1 °Ra [0.5 K]
Factory setting (Arr = 2 only):
MN3O: 40.0 °F [5.0 °C]
MN3F: 50.0 °F [10.0 °C]
Minimum and maximum temperature limits can be set for
the heat exchange function.
The maximum temperature limitation uses sensor 4 as
reference sensor.
The maximum temperature limitation function provides
a maximum tem­perature setting, usually to reduce scald
risk in a storage tank. If MX3O is exceeded, relay 2 is
switched off until the temperature at sensor 4 falls below
MX3F.
The minimum temperature limitation uses sensor 3 as
reference sensor.
The minimum temperature limitation function provides
a minimum tem­perature setting for the heat source in
system layout 2. If the temperature at sensor 3 falls below
MN3O, relay 2 is switched off until the temperature at
sensor 3 exceeds MN3F.
© Viessmann 5443203
Both switch-on and switch-off temperature differences
DT3O and DT3F are valid for the maximum and minimum
temperature limitation.
11 |
SCU224
System layout 3
The controller calculates the temperature difference between collector sensor S1 and tank sensor S2. If the difference is larger than or identical to the adjusted switch-on
temperature difference (DT O), the solar pump will be
operated by relay 1, and the tank will be loaded until the
switch-off temperature difference (DT F) or the maximum
tank temperature (S MX) is reached.
Sensor S3 is used for a thermostatic function, which ope-
Arr 3
rates relay 2 for backup heating or heat dump purposes,
when the adjusted thermostat switch-on temperature
(AH O) is reached. This function can optionally be combined with up to three adjustable time frames.
Sensor S3 can also be optionally used as a reference sensor
for the thermal disinfection function OTD.
Sensor S4 can optionally be connected for measurement
purposes. If energy metering (OHQM) is activated, sensor
S4 has to be connected as return sensor.
S1
R1
S3
R2
Display Channels
Channel
Description
x*
INIT
ODB initialization active
x*
FLL
ODB filling time active
x*
STAB
ODB stabilization in progress
COL
x
Temperature collector
TSTB
x
Temperature tank 1 bottom
TSTT
x
Temperature tank 1 at the top
s*
TDIS
Thermal disinfection temperature
S4
x
Temperature sensor 4
TR
x*
Temperature return sensor
n1 %
x
Pump speed R1
h P1
x
Operating hours R1
h P2
x
Operating hours R2
x*
kWh
Heat quantity kWh
x*
MWh
Heat quantity MWh
s*
CDIS
Countdown of monitoring period
s*
SDIS
Starting time display
s*
DDIS
Heating period display
TIME
x
Time
| 12
S2
Terminal
S1
S2
S3
S3
S4
S4
R1
R1
R2
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© Viessmann 5443203
S4 / TR
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT O
x
Switch-on temperature difference
DT F
x
Switch-off temperature difference
DT S
x
Nominal temperature difference
RIS
x
Rise control R1
n1MN
x
Minimum pump speed R1
S MX
x
Maximum tank temperature
Emergency temperature collector
EM
x
Emergency temperature collector if ODB is activated:
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
OHQM
x
Option energy metering
FMAX
x*
Maximum flow
MEDT
x*
Antifreeze type
MED%
x*
Antifreeze concentration
AH O
s
Switch-on temp. for thermostat 1
AH F
s
Switch-off temp. for thermostat 1
t1 O
s
Switch-on time 1 thermostat
t1 F
s
Switch-off time 1 thermostat
t2 O
s
Switch-on time 2 thermostat
t2 F
s
Switch-off time 2 thermostat
t3 O
s
Switch-on time 3 thermostat
t3 F
s
Switch-off time 3 thermostat
ODB
x
Drainback option
tDTO
x*
ODB switch-on condition - time period
tFLL
x*
ODB filling time
tSTB
x*
ODB stabilization time
OTD
s
Option thermal disinfection
PDIS
s*
Monitoring period
DDIS
s*
Heating period
TDIS
s*
Disinfection temperature
SDIS
s*
Starting time
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
3
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
270 °F [130 °C]
200 °F [95 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
OFF
07:00
19:00
30 s
30 min
OFF
6.0 l
1
45 %
110 °F [40 °C]
120 °F [45 °C]
00:00
00:00
00:00
00:00
00:00
00:00
OFF
60 s
5.0 min
2.0 min
OFF
01:00
01:00
140 °F [60 °C]
00:00
Auto
Auto
En
°C
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© Viessmann 5443203
Legend:
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
s
Channel is specifically available in this system layout
s*
System-specific channel, only available if the corresponding option is activated
13 |
SCU224
System-specific functions
The following functions are exclusively available in system
layout 3.The corresponding channels will not be available in
any other system layout.
Thermostat function
Backup heating
The thermostat function works independently from the
solar operation and can be used for using surplus energy
or for backup heating.
• AH O< AH F
thermostat function for backup heating
• AH O> AH F
thermostat function for using surplus energy
Use of surplus energy
The symbol
will be shown on the display if the second
relay output is activated.
Reference sensor for the thermostat function is S3!
AH O:
Thermostat switch-on ­tem­p.
Adjustment range:
30.0 ... 200.0 °F
[0.0 ... 95.0 °C]
in steps of 1.0 °Ra [0.5 K]
Factory setting:
110.0°F [40.0 °C]
AH F:
Thermostat switch-off tem­p.
Adjustment range:
30.0 ... 200.0 °F
[0.0 ... 95.0 °C]
in steps of 1.0 °Ra [0.5 K]
Factory setting:
120.0 °F [45.0 °C]
t1 O, t2 O, t3 O:
Thermostat switch-on time
Adjustment range:
00:00 ... 23:45
Factory setting: 00:00
© Viessmann 5443203
t1 F, t2 F, t3 F:
Thermostat switch-off time
Adjustment range:
00:00 ... 23:45
Factory setting: 00:00
In order to block the thermostat function for a certain
period, there are three time frames t1 ... t3. If the function
should be active between 6:00 and 9:00, set t1 O to 6:00
and t1 F to 9:00.
If all time frames are set to 00:00 o’clock, the thermostat
function is continuously activated (factory setting).
| 14
SCU224
Option:Thermal disinfection of the upper DHW
zone (OTD)
OTD:
Thermal disinfection function
Adjustment range: ON / OFF
Factory setting: OFF
PDIS:
Monitoring period
Adjustment range:
0 ... 30:0 ... 24 h (dd:hh)
Factory setting: 01:00
DDIS
Heating period
Adjustment range:
00:00 ... 23:59 (hh:mm)
Factory setting: 01:00
TDIS
Disinfection temperature
Adjustment range:
30 ... 200 °F
[0 ... 95 °C]
in steps of 2 °F [2 °C]
Factory setting:
140 °F [60 °C]
This function is used for protecting the upper tank zone
against Legionella by activating the backup heating.
Reference sensor for the thermal disinfection is S3!
ÎÎ To activate the function, select “On” in the OTD
channel.
For thermal disinfection, the temperature in the upper
DHW tank zone has to be monitored. This protection is
ensured when, during the monitoring period (PDIS), the
disinfection temperature (TDIS) is continuously exceeded
for the entire heating period (DDIS). S3 is used as the
reference sensor and displayed as TSTT.
If OTD is activated, PDIS will start as soon as the temperature at S3 falls below TDIS. The display channel CDIS
appears, counting backwards the remaining time of PDIS.
If, during the monitoring period, the temperature at S3
exceeds TDIS continuously for the duration of DDIS,
thermal disinfection is considered complete and a new
monitoring period begins.
If CDIS counts down to 00:00, relay 2 will be operated in
order to use the backup heating for thermal disinfection.
CDIS will then be replaced with a display channel DDIS
showing the adjusted heating period. DDIS will start counting down the heating period as soon as TDIS is exceeded
at S3. As long as DDIS is active, the temperature at S3 will
be displayed as TDIS instead of TSTT.
If, during DDIS, the temperature at S3 exceeds TDIS by
more than 10 °Ra [5 K], relay 2 is switched off until the
temperature falls below TDIS + 4 °Ra [2 K].
If, during DDIS, the temperature at S3 falls below TDIS,
the heating period will restart. DDIS can only be completed when TDIS is exceeded without interruption.
Due to the flexible control logic, the exact time of thermal
disinfection is not predictable. In order to set a fixed time
for the disinfection to be run, the starting delay SDIS must
be employed:
Thermal disinfection with starting delay
© Viessmann 5443203
SDIS
Starting time
Adjustment range:
00:00 ... 24:00 (o‘clock)
Factory setting: 00:00
When a starting time for thermal disinfection with starting
delay is adjusted in SDIS, the thermal disinfection will be
delayed until that time, even after the CDIS has counted
down to 00:00. If CDIS ends, for example, at 12:00 o‘clock,
and SDIS has been set to 18:30, relay 2 will be operated
with a delay of 6.5 hours at 18:30 instead of 12:00.
During the waiting time, SDIS is displayed with the adjusted
starting time (flashing).
If, during the waiting time, the temperature at S3 exceeds
TDIS for the adjusted heating period DDIS, thermal
disinfection is considered complete and a new monitoring
period begins.
If the starting time is adjusted to 00:00 (factory setting), the
delay function is inactive.
Upon delivery, OTD is deactivated. The adjustment values
PDIS, TDIS, DDIS and SDIS are displayed after the
option has been activated. After the thermal disinfection
function has been completed, the values will be “hidden”
and the monitoring period will be displayed.
15 |
SCU224
System layout 4
The controller calculates the temperature differences
between collector sensor S1 and tank sensors S2 and S3. If
the differences are larger than or identical to the adjusted
switch-on temperature differences (DT1O / DT2O), the
solar pump will be operated by relay 1, and the respective
tank zone will be loaded until the switch-off temperature
differences (DT1F / DT2F) or the maximum tank tempera-
tures (S1MX / S2MX) are reached.The priority logic causes
priority loading of the upper zone of the tank, if possible.
The 3-way-valve will be operated by relay 2 then.
Sensor S4 can optionally be connected for measurement
purposes.
If energy metering (OHQM) is activated, sensor S4 has to
be connected as return sensor.
Arr 4
S1
R1
R2
S3
Display Channels
Channel
Description
COL
x
Temperature collector
TSTB
x
Temperature tank 1 bottom
TSTT
x
Temperature tank 1 at the top
S4
x
Temperature sensor 4
TR
x*
Temperature return sensor
n%
x
Pump speed relay
hP1
x
Operating hours R1
hP2
x
Operating hours R2
x*
kWh
Heat quantity kWh
x*
MWh
Heat quantity MWh
TIME
x
Time
| 16
S2
Terminal
S1
S2
S3
S4
S4
R1
R1
R2
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© Viessmann 5443203
S4 / TR
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
nMN
x
Minimum pump speed
DT1O
x
Switch-on temperature difference 1
DT1F
x
Switch-off temperature difference 1
DT1S
x
Nominal temperature difference 1
RIS1
x
Rise control R1
S1 MX
x
Maximum temperature tank 1
DT2O
x
Switch-on temperature difference 2
DT2F
x
Switch-off temperature difference 2
DT2S
x
Nominal temperature difference 2
RIS2
x
Rise control R2
S2MX
x
Maximum temperature tank 2
EM
x
Emergency temperature collector
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
PRIO
x
Priority
tLB
x
Break time
tRUN
x
Circulation runtime
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
OHQM
x
Option energy metering
FMAX
x*
Maximum flow
MEDT
x*
Antifreeze type
MED%
x*
Antifreeze concentration (only if MEDT = propylene or ethylene)
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
4
30 %
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
140 °F [60 °C]
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
140 °F [60 °C]
270 °F [130 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
2
2 min
15 min
OFF
07:00
19:00
30 s
30 min
OFF
6.0 l
1
45 %
Auto
Auto
En
°C
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Legend:
© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
17 |
SCU224
System layout 5
The controller calculates the temperature differences
between collector sensor S1 and tank sensors S2 and S3. If
the differences are larger than or identical to the adjusted
switch-on temperature differences (DT1O / DT2O), the solar pump will be operated by relay 1, and the respective tank
will be loaded until the switch-off temperature differences
(DT1F / DT2F) or the maximum tank temperatures (S1MX /
S2MX) are reached.The priority logic causes priority loading
of tank 1, if possible. For loading tank 2 the 3-way-valve will
be operated by relay 2.
Sensor S4 can optionally be connected for measurement
purposes.
If energy metering (OHQM) is activated, sensor S4 has to
be connected as return sensor.
Arr 5
S1
R2
Tank 1
Tank 2
R1
S4 / TR
Display Channels
Channel
Description
COL
x
Temperature collector
TST1
x
Temperature tank 1 bottom
TST2
x
Temperature tank 2 bottom
S4
x
Temperature sensor 4
TR
x*
Temperature return sensor
n%
x
Pump speed relay
hP1
x
Operating hours R1
hP2
x
Operating hours R2
x*
kWh
Heat quantity kWh
x*
MWh
Heat quantity MWh
x
TIME
Time
| 18
S3
Terminal
S1
S2
S3
S4
S4
R1
R1
R2
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© Viessmann 5443203
S2
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
nMN
x
Minimum pump speed
DT1O
x
Switch-on temperature difference 1
DT1F
x
Switch-off temperature difference 1
DT1S
x
Nominal temperature difference 1
RIS1
x
Rise control R1
S1 MX
x
Maximum temperature tank 1
DT2O
x
Switch-on temperature difference 2
DT2F
x
Switch-off temperature difference 2
DT2S
x
Nominal temperature difference 2
RIS2
x
Rise control R2
S2MX
x
Maximum temperature tank 2
EM
x
Emergency temperature collector
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
PRIO
x
Priority
tLB
x
Break time
tRUN
x
Circulation runtime
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
OHQM
x
Option energy metering
FMAX
x*
Maximum flow
MEDT
x*
Antifreeze type
MED%
x*
Antifreeze concentration (only if MEDT = propylene or ethylene)
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
5
30 %
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
140 °F [60 °C]
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
140 °F [60 °C]
270 °F [130 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
1
2 min
15 min
OFF
07:00
19:00
30 s
30 min
OFF
6.0 l
1
45 %
Auto
Auto
En
°C
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Legend:
© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
19 |
SCU224
System layout 6
The controller calculates the temperature differences
between collector sensor S1 and tank sensors S2 and S3. If
the differences are larger than or identical to the adjusted
switch-on temperature differences (DT1O / DT2O), the
solar pumps will be operated by relay 1 and / or relay 2,
and the respective tank will be loaded until the switch-off
temperature differences (DT1F / DT2F) or the maximum
tank temperatures (S1MX / S2MX) are reached.The priority
logic causes priority loading of the selected tank (PRIO), if
possible. Loading both tanks simultaneously is possible as
well (PRIO = 0).
Sensor S4 can optionally be connected for measurement
purposes.
Arr 6
S1
S4
R2
Tank 1
Tank 2
S2
Display Channels
Channel
Description
COL
x
Temperature collector
TST1
x
Temperature tank 1 bottom
TST2
x
Temperature tank 2 bottom
S4
x
Temperature sensor 4
n1 %
x
Pump speed R1
n2 %
x
Pump speed R2
h P1
x
Operating hours R1
h P2
x
Operating hours R2
TIME
x
Time
| 20
S3
Terminal
S1
S2
S3
S4
R1
R2
R1
R2
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© Viessmann 5443203
R1
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT1O
x
Switch-on temperature difference 1
DT1F
x
Switch-off temperature difference 1
DT1S
x
Nominal temperature difference 1
RIS1
x
Rise control R1
n1MN
x
Minimum pump speed R1
S1 MX
x
Maximum temperature tank 1
DT2O
x
Switch-on temperature difference 2
DT2F
x
Switch-off temperature difference 2
DT2S
x
Nominal temperature difference 2
RIS2
x
Rise control R2
n2MN
x
Minimum pump speed R2
S2MX
x
Maximum temperature tank 2
EM
x
Emergency temperature collector
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
PRIO
x
Priority
tLB
x
Break time
tRUN
x
Circulation runtime
DTSE
x*
Spread temperature difference
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
6
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
270 °F [130 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
1
2 min
15 min
70 °Ra [40 K]
OFF
07:00
19:00
30 s
30 min
Auto
Auto
En
°C
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© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
21 |
SCU224
System layout 7
The controller calculates the temperature differences
between the collector sensors S1 and S3 and the tank
sensor S2. If the differences are larger than or identical to
the adjusted switch-on temperature difference (DT O), the
respective solar pump will be operated by relay 1 and / or
relay 2, and the tank will be loaded until the switch-off
temperature difference (DT F) or the maximum tank temperature (S MX) is reached.
Sensor S4 can optionally be connected for measurement
purposes.
Arr 7
S1
R1
S3
R2
Display Channels
Channel
Description
COL1
x
Temperature collector 1
TST
x
Temperature tank
COL2
x
Temperature collector 2
S4
x
Temperature sensor 4
n1 %
x
Pump speed R1
n2 %
x
Pump speed R2
h P1
x
Operating hours R1
h P2
x
Operating hours R2
TIME
x
Time
| 22
Terminal
S1
S2
S3
S4
R1
R2
R1
R2
-
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© Viessmann 5443203
S2
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT O
x
Switch-on temperature difference
DT F
x
Switch-off temperature difference
DT S
x
Nominal temperature difference
RIS
x
Rise control R1 / R2
n1MN
x
Minimum pump speed R1
S MX
x
Maximum tank temperature
n2MN
x
Minimum pump speed R2
EM1
x
Emergency temperature collector
EM2
x
Emergency temperature collector
OCC1
x
Option collector cooling collector 1
CMX1
x*
Maximum temperature collector 1
OCC2
x
Option collector cooling collector 2
CMX2
x*
Maximum temperature collector 2
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN1
x
Option minimum limitation collector 1
CMN1
x*
Minimum temperature collector 1
OCN2
x
Option minimum limitation collector 2
CMN2
x*
Minium temperature collector 2
OCF1
x
Option antifreeze collector 1
CFR1
x*
Antifreeze temperature collector 1
OCF2
x
Option antifreeze collector 2
CFR2
x*
Antifreeze temperature collector 2
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
7
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
30 %
270 °F [130 °C]
270 °F [130 °C]
OFF
230 °F [110 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
OFF
40.0 °F [4.0 °C]
OFF
07:00
19:00
30 s
30 min
Auto
Auto
En
°C
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© Viessmann 5443203
Legend:
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
23 |
SCU224
System layout 8
The controller calculates the temperature difference between collector sensor S1 and tank sensor S2. If the difference is larger than or identical to the adjusted switch-on
temperature difference (DT O), the solar pump will be
operated by relay 1, and the tank will be loaded until the
switch-off temperature difference (DT F) or the maximum
tank temperature (S MX) is reached.
A solid fuel boiler will be operated by relay 2, if the temperature difference between sensors S4 and S3 is larger than or
identical to the adjusted switch-on temperature difference
(DT3O), until the adjusted minimum (MN3O) and maximum
(MX3O) temperature thresholds of the fuel boiler and the
tank are reached.
Arr 8
S1
S4
R1
S3
R2
Display Channels
Channel
Description
x*
INIT
ODB initialization active
x*
FLL
ODB filling time active
x*
STAB
ODB stabilization in progress
COL
x
Temperature collector
TSTB
x
Temperature tank 1 bottom
TSTT
x
Temperature tank 1 at the top
TSFB
x
Temperature solid fuel boiler
n1 %
x
Pump speed R1
n2 %
x
Pump speed R2
h P1
x
Operating hours R1
h P2
x
Operating hours R2
TIME
x
Time
| 24
Terminal
S1
S2
S3
S4
R1
R2
R1
R2
-
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© Viessmann 5443203
S2
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT O
x
Switch-on temperature difference
DT F
x
Switch-off temperature difference
DT S
x
Nominal temperature difference
RIS
x
Rise control R1
n1MN
x
Minimum pump speed R1
S MX
x
Maximum tank temperature
n2MN
s
Minimum pump speed R2
Emergency temperature collector
EM
x
Emergency temperature collector if ODB is activated:
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
DT3O
s
Switch-on temperature difference 3
DT3F
s
Switch-off temperature difference 3
DT3S
s
Nominal temperature difference 3
RIS3
s
Rise control R2
MX3O
s
Switch-on treshold for maximum temperature
MX3F
s
Switch-off treshold for maximum temperature
MN3O
s
Switch-on treshold for minimum temperature
MN3F
s
Switch-off treshold for minimum temperature
ODB
x
Drainback option
tDTO
x*
ODB switch-on condition - time period
tFLL
x*
ODB filling time
tSTB
x*
ODB stabilization time
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
8
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
30 %
270 °F [130 °C]
200 °F [95 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
OFF
07:00
19:00
30 s
30 min
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
140.0 °F [60.0 °C]
136.0 °F [58.0 °C]
140.0 °F [60.0 °C]
150.0 °F [65.0 °C]
OFF
60 s
5.0 min
2.0 min
Auto
Auto
En
°C
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© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
s
Channel is specifically available in this system layout
25 |
SCU224
System-specific functions
The following adjustments are used for the specific functions
in system layout 8.
∆T control for backup heating by solid fuel boiler
Reference sensors for this function are S4 and S3.
In system layout 8, the controller is equipped with an additional differential control for heat exchange from a solid
fuel boiler (e.g. woodstove). The basic differential function
is adjusted using the switch-on (DT3O) and switch-off
(DT3F) temperature differences.
When the switch-on difference is reached, relay 2 switches on. When the temperature difference falls below
the adjusted switch-off temperature difference, relay 2
switches off.
DT3O:
Switch-on temperature diff.
Adjustment range:2.0 ... 40.0°Ra
[1.0 ... 20.0 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 12.0°Ra
[6.0 K]
DT3F:
Switch-off temperature ­diff.
Adjustment range:1.0 ... 39.0°Ra
[0.5 ... 19.5 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 8.0°Ra
[4.0 K]
Pump speed control
DT3S:
Nominal temperature difference
Adjustment range:3.0 ... 60.0 °Ra
[1.5 ... 30.0 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 20.0 °Ra
[10.0 K]
RIS3:
Rise
Adjustment range:
2 ... 40 °Ra
[1 ... 20 K]
in steps of 2 °Ra [1 K]
Factory setting: 4 °Ra [2 K]
Minimum pump speed
Note:
For pump speed control of the solid fuel boiler
pump, the operation mode of relay 2 (MAN2)
must be set to Auto.
When the switch-on temperature difference is reached, the
pump is activated at full speed for 10 seconds.Then, the speed
is reduced to the minimum pump speed value (n2MN).
If the temperature difference reaches the adjusted nominal
temperature difference (DT3S), the pump speed increases by
one step (10 %). If the difference increases by the adjustable rise
value, the pump speed increases by 10 % respectively until the
maximum pump speed of 100 % is reached.The response of
the controller can be adapted via the parameter RIS3.
Note:
The nominal temperature difference must be
at least 1 °Ra [0.5 K] higher than the switch-on
tempe­rature ­difference.
A relative minimum pump speed can be allocated to the
output R2 via the adjustment channel n2MN.
Note:
When loads which are not speed-controlled (e.g.
valves) are used, the value must be set to 100 % in
order to deactivate pump speed control.
© Viessmann 5443203
n2MN:
Pump speed control
Adjustment range:
30 ... 100
in steps of 5 %
Factory setting: 30
Note:
The switch-on temperature difference must be
at least 1 °Ra [0.5 K] higher than the switch-off
tempe­rature ­difference.
| 26
SCU224
Maximum temperature limitation
MX3O / MX3F:
Maximum temperature limitation
Adjustment range:
30.0 ... 200.0 °F
[0.0 ... 95.0 °C]
in steps of 1 °Ra [0.5 K]
Factory setting:
MX3O: 140.0 °F [60.0 °C]
MX3F: 136.0 °F [58.0 °C]
Minimum temperature limitation
MN3O / MN3F:
Minimum temperature limitation
Adjustment range:
30.0 ...190.0 °F
[0.0 ... 90.0 °C]
in steps of 1 °Ra [0.5 K]
Factory setting (Arr = 8 only):
MN3O: 140.0 °F [60.0 °C]
MN3F: 150.0 °F [65.0 °C]
Minimum and maximum temperature limits can be set for
the solid fuel boiler.
The maximum temperature limitation function provides a
maximum tem­perature setting, usually to reduce scald risk
in a storage tank. If MX3O is exceeded, relay 2 is switched
off until the sensor falls below MX3F. TIn Arr 8, this function uses sensor 3 as reference sensor.
The minimum temperature limitation uses sensor 4 as
reference sensor.
The minimum temperature limitation function provides a
minimum tem­perature setting for the solid fuel boiler in
system layout 8. If the temperature at sensor 4 falls below
MN3O, relay 2 is switched off until the temperature exceeds MN3F again.
© Viessmann 5443203
Both switch-on and switch-off temperature differences
DT3O and DT3F are valid for the maximum and minimum
temperature limitation.
27 |
SCU224
System layout 9
The controller calculates the temperature difference between collector sensor S1 and tank sensor S2. If the difference is larger than or identical to the adjusted switch-on
temperature difference (DT O), the solar pump will be
operated by relay 1, and the tank will be loaded until the
switch-off temperature difference (DT F) or the maximum
tank temperature (S MX) is reached.
A heating circuit return preheating will be operated by
relay 2, if the temperature difference between sensors S3
and S4 is larger than or identical to the adjusted switch-on
temperature difference (DT3O). For this purpose, relay 2
will operate the 3-way-valve.
Arr 9
S1
R1
S4
S3
Display Channels
Channel
Description
x*
INIT
ODB initialization active
x*
FLL
ODB filling time active
x*
STAB
ODB stabilization in progress
COL
x
Temperature collector
TSTB
x
Temperature tank 1 bottom
TSTT
x
Temperature tank 1 at the top
TRET
x
Temperature heating circuit
n%
x
Pump speed relay
hP1
x
Operating hours R1
hP2
x
Operating hours R2
TIME
x
Time
| 28
R2
Terminal
S1
S2
S3
S4
R1
R1
R2
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© Viessmann 5443203
S2
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT O
x
Switch-on temperature difference
DT F
x
Switch-off temperature difference
DT S
x
Nominal temperature difference
RIS
x
Rise control R1
nMN
x
Minimum pump speed
S MX
x
Maximum tank temperature
Emergency temperature collector
EM
x
Emergency temperature collector if ODB is activated:
OCC
x
Option collector cooling
CMX
x*
Maximum collector temperature
OSYC
x
Option system cooling
DTCO
x*
Cooling switch-on temperature difference
DTCF
x*
Cooling switch-off temperature difference
OSTC
x
Option tank cooling
OHOL
x*
Option holiday cooling
THOL
x*
Holiday cooling temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
DT3O
s
Switch-on temperature difference 3
DT3F
s
Switch-off temperature difference 3
ODB
x
Drainback option
tDTO
x*
ODB switch-on condition - time period
tFLL
x*
ODB filling time
tSTB
x*
ODB stabilization time
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
9
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
270 °F [130 °C]
200 °F [95 °C]
OFF
230 °F [110 °C]
OFF
40.0 °Ra [20.0 K]
30.0 °Ra [15.0 K]
OFF
OFF
110 °F [40 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
OFF
07:00
19:00
30 s
30 min
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
OFF
60 s
5.0 min
2.0 min
Auto
Auto
En
°C
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Legend:
© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
s
Channel is specifically available in this system layout
29 |
SCU224
System layout 10
The controller calculates the temperature difference between collector sensor S1 and tank sensor S2. If the difference is larger than or identical to the adjusted switch-on
temperature difference (DT O), the solar pump will be
operated by relay 1, and the tank will be loaded until the
switch-off temperature difference (DT F) or the maximum
tank temperature (S MX) is reached.
If the maximum collector temperature (CMX) is reached, the
solar pump will be operated by relay 1 and the 3-way-valve
will be operated by relay 2 in order to direct the surplus
energy to a heat dump. For security purpose this will be
carried out only if the tank temperature is below the nonadjustable emergency shutdown of 200 °F.
Sensors S3 and S4 can optionally be connected for measurement purposes.
If energy metering (OHQM) is activated, sensor S4 has to
be connected as return sensor.
VBus
Arr 10
9 10
S1
R2
R1
S3
S4 / TR
Display Channels
Channel
Description
COL
x
Temperature collector
TST
x
Temperature tank
S3
x
Temperature sensor 3
S4
x
Temperature sensor 4
x*
TR
Temperature return sensor
n%
x
Pump speed relay
h P1
x
Operating hours R1
h P2
x
Operating hours R2
kWh
x*
Heat quantity kWh
MWh
x*
Heat quantity MWh
TIME
x
Time
| 30
Terminal
S1
S2
S3
S4
S4
R1
R1
R2
-
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© Viessmann 5443203
S2
SCU224
Adjustment Channels
Channel
Description
Arr
x
System
DT O
x
Switch-on temperature difference
DT F
x
Switch-off temperature difference
DT S
x
Nominal temperature difference
RIS
x
Rise control R1
nMN
x
Minimum pump speed
S MX
x
Maximum tank temperature
EM
x
Emergency temperature collector
CMX
s
Maximum collector temperature
OCN
x
Option minimum limitation
CMN
x*
Minimum collector temperature
OCF
x
Option antifreeze
CFR
x*
Antifreeze temperature
O TC
x
Option tube collector
TCST
x*
OTC starting time
TCEN
x*
OTC ending time
TCRU
x*
OTC runtime
TCIN
x*
OTC standstill interval
OHQM
x
Option energy metering
FMAX
x*
Maximum flow
MEDT
x*
Antifreeze type
MED%
x*
Antifreeze concentration (only if MEDT = propylene or ethylene)
MAN1
x
Manual operation R1
MAN2
x
Manual operation R2
LANG
x
Language
UNIT
x
Temperature unit
RESE
x
Reset - back to factory defaults
W0050100
Version number
Factory setting
10
12.0 °Ra [6.0 K]
8.0 °Ra [4.0 K]
20.0 °Ra [10.0 K]
4 °Ra [2 K]
30 %
140 °F [60 °C]
270 °F [130 °C]
230 °F [110 °C]
OFF
50 °F [10 °C]
OFF
40.0 °F [4.0 °C]
OFF
07:00
19:00
30 s
30 min
OFF
6.0 l
1
45 %
Auto
Auto
En
°C
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Legend:
© Viessmann 5443203
Symbol
Specification
x
Channel is available
x*
Channel is available if the corresponding option is activated.
s
Channel is specifically available in this system layout
31 |
SCU224
2. Operation and function
2.1Push buttons
operating control lamp
forward
backward
2
3
1
SET
(selection / adjustment mode)
2.2System monitoring display
!
system monitoring display
channel display
The controller is operated via three push buttons below the
display. Button 1 is used for scrolling forward through the
indication menu or to increase the adjustment values. Button 2 is used for scrolling backward and reducing values.
During normal operation, only the display channels are
shown.
ÎÎ Scroll through the display channels by pressing buttons
1 and 2
Accessing the adjustment channels:
ÎÎ Scroll down in the display menu and press the forward
button (1) for approx. two seconds after you have
reached the last display item.
When an adjustment value is shown on the display, SET
is indicated to the right of the channel name.
ÎÎ Press the “Set” button (3) in order to access the adjustment mode
SET starts flashing.
ÎÎ Adjust the value using buttons 1 and 2
ÎÎ Briefly press button 3, SET permanently appears,the
adjusted value will be saved.
The system monitoring display consists of three blocks:
channel display, tool bar and system screen (active
system layout).
The channel display consists of two lines.The upper line is an
alpha-numeric 16-segment display (text display) for displaying
channel names and menu items. In the lower 7-segment
display, the channel values and the adjustment parameters
are displayed.
Temperatures are either indicated in °F or °C, whereas temperature differences are indicated in K or °Ra respectively.
The additional symbols of the tool bar indicate the current
system status.
Status
standard flashing
relay 1 active
relay 2 active
maximum tank temperature exceeded
tool bar
+
tank emergency shutdown active
collector emergency shutdown active
collector cooling active
system cooling active
tank cooling active
+
holiday cooling function activated
holiday cooling function active
+
collector minimum limitation active
antifreeze function active
manual operation relay 1 ON
manual operation relay 2 ON
manual operation relay 1 / 2 OFF
sensor defective
| 32
/
+
+
© Viessmann 5443203
antifreeze function activated
SCU224
System screen
The system screen (active system layout) shows the system
selected on the controller. It consists of several system
component symbols, which are – depending on the current
status of the system – either flashing, permanently shown
or hidden.
system screen
sensors
collector 2
tank sensor
at the top
heating circuit
collector 1
valve
valve
pumps
sensor
additional symbol for
operation of the burner
tank heat exchanger
tank
tank 2 or backup heating (with
an additional symbol)
Temperature sensor
Collectors
with collector sensor
Heating circuit
Tanks 1 and 2
with heat exchanger
Pump
3-way valve
The flow direction or the
actual switching position is
shown
Backup heating
with burner symbol
© Viessmann 5443203
2.3Flashing codes
System screen flashing codes
• Pumps are flashing during initialization phase
• Sensor symbols are flashing if the corresponding sensor
display channel is selected.
• Sensors are flashing in the case of a sensor fault.
• Burner symbol is flashing if the backup heating is active
LED flashing codes
green:
red/green flashing
red flashing:
everything OK
initialization phase
manual operation
sensor fault
(sensor symbol is flashing quickly)
33 |
SCU224
3. Commissioning
2
3
1
(SET)
The three pushbuttons of the BS Plus controller
ÎÎ Establish the power supply
During a short initialization phase, the operating control
lamp flashes red and green.
When the controller is commissioned for the first time
or after a reset, it will run a commissioning menu. The
commissioning menu leads the user through the most
important adjustment channels needed for operating the
system.
Operating the commissioning menu:
ÎÎ Enter the channel by pressing button 3
The
symbol flashes.
ÎÎ Adjust the value by pressing buttons 1 and 2
ÎÎ Save the adjustment by pressing button 3 again
The
symbol stops flashing.
ÎÎ Press button 1 or 2 to switch to the next or previous
channel
The commissioning menu consists of the following 6
channels:
1. Language
ÎÎ Adjust the desired menu language in this channel
• dE : German
• En : English
UNIT:
Temperature unit selection
Selection: °F, °C
Factory setting: °C
2. Unit
ÎÎ Adjust the unit in which temperatures and temperature
differences shall be displayed
TIME:
Real time adjustment
3. Time
ÎÎ Adjust the current time for the real time clock
The hours and minutes have to be adjusted separately, first
the hours, then the minutes.
© Viessmann 5443203
LANG:
Language selection
Selection: dE, En
Factory setting: En
| 34
SCU224
Arr:
System layout selection
Adjustment range:1 ... 10
Factory setting: 1
4. System layout
ÎÎ Adjust the desired system layout of your solar thermal
system
For a detailed description of the different system layouts
selectable, see chapter 1.4.
Overview of system layouts:
Arr 1
Arr 2
Arr 1 : standard solar system layout
Arr 2 : solar system layout with heat exchange
Arr 3
Arr 4
Arr 3 : solar system layout with backup heating
Arr 4 : solar system layout with vertical tank charging
Arr 5
Arr 6
Arr 5 : 2-tank solar system layout with valve logic
Arr 6 : 2-tank solar system layout with pump logic
Arr 7
Arr 8
Arr 7 : solar system layout with 2 collectors and 1 tank
Arr 8 : solar system layout with backup heating by solid fuel
boiler
Arr 9
Arr 10
Arr 9 : solar system layout with heating circuit return
preheating
Arr 10: standard solar system layout with heat dump
If the system layout selection is changed later on, any
previous adjustments which have been made in the other
channels will be lost. Therefore, changing the system layout
is always followed by a security enquiry.
Only confirm the security enquiry if you are sure that
you wish to change the system layout selection!
ÎÎ To confirm the security enquiry, press button 3
© Viessmann 5443203
Security enquiry:
35 |
SCU224
S MX / S1MX / S2MX:
Maximum tank temp.
Adjustment range:
40 ... 200 °F
[4 ... 95 °C]
Arr 10:
40 ... 190 °F
[4 ... 90 °C]
in steps of 2 °Ra [1 K]
Factory setting:140 °F [60 °C]
5. Maximum tank temperature
ÎÎ Adjust the desired maximum tank temperature
nMN, n1MN, n2MN:
Pump speed control
Adjustment range:
30 ... 100
in steps of 5 %
Factory setting: 30
6. Minimum pump speed
ÎÎ Adjust a minimum speed for the pump
Confirmation enquiry
Completing the commissioning menu
After the last channel of the commissioning menu has been
adjusted and confirmed, the controller asks for confirmation of the adjustments.
ÎÎ To confirm the adjustments made in the commissioning
menu, press button 3
Note:
The controller is also equipped with a nonadjustable emergency shutdown function, which
will shut the system down if the tank reaches
200 °F [95 °C].
Note:
If loads which are not speed-controlled (e.g.
valves) are used, the value must be set to 100 % for
the respective relay.
© Viessmann 5443203
Now the controller is ready for operation with typical
settings to suit the selected system layout.
The settings made in the commissioning menu can be
changed later on in the corresponding adjustment channels.
Additional functions and options can of course be individually adjusted as well (see chap. 4.2).
| 36
SCU224
4. Channel overview
4.1Display channels
Indication of drainback time periods
Initialization
Note:
The displayed values and adjustment channels
depend on which system layout, which options
and functions have been selected. Only values
and adjustment channels available for the individual settings selected will appear in the menu.
Indicates the time adjusted in tDTO, running backwards.
INIT:
ODB initialization active
Filling time
Indicates the time adjusted in tFLL, running backwards.
FLL:
ODB filling time active
Stabilization
Indicates the time adjusted in tSTB, running backwards.
STAB:
Stabilization
Indication of collector temperatures
COL, COL1, COL2:
Collector temperature
Display range: -40 ... +500 °F
[-40 ... +260 °C]
• COL : collector temperature (1-collector system)
• COL1: collector temperature 1
• COL2: collector temperature 2
Indication of tank temperatures
Indicates the current tank temperature.
TST,TSTB,TSTT,
TST1,TST2,TDIS:
Tank temperatures
Display range: -40 ... +500 °F
[-40 ... +260 °C]
•• TST :
tank temperature (1-tank system)
•• TSTB :
tank temperature bottom
•• TSTT:
tank temperature top
(Arr = 3 and 4 only)
•• TST1 :
temperature tank 1 (2-tank-systems)
•• TST2 :
temperature tank 2 (2-tank-systems)
•• TDIS :
thermal disinfection temperature
(Arr = 3 only; replaces TSTT if, during thermal disinfection, the heating period DDIS is active)
Indication of sensors 3 and 4
Indicates the current temperature of the corresponding
additional sensor (without control function).
• S3 : temperature sensor 3
• S4 : temperature sensor 4
S3, S4:
Sensor temperatures
Display range: -40 ... +500 °F
[-40 ... +260 °C]
Indication of other temperatures
© Viessmann 5443203
Indicates the current collector temperature.
TSFB,TRET,TR:
Other mea­sured tempe­ratures
Display range: -40 ... +500 °F
[-40 ... +260 °C]
Note:
S3 and S4 will only be indicated if the temperature
sensors are connected.
Indicates the current temperature of the corresponding
sensor.
• TSFB : temperature solid fuel boiler
• TRET: temperature heating return preheating
• TR : temperature return
37 |
SCU224
n %, n1 %, n2 %:
Current pump speed
Display range: 30 ... 100 %
kWh/MWh: Heat quantity
in kWh / MWh
Display channel
Indicates the current pump speed of the corresponding
pump.
• n % : current pump speed (1-pump system)
• n1 % : current pump speed pump 1
• n2 % : current pump speed pump 2
Indicates the energy gained in heat quantity – only available
if energy metering (OHQM) is activated.
The flow rate as well as the reference sensors S1 (flow) and
S4 (return) are used for calculating the heat quantity supplied. It is shown in kWh in the channel kWh and in MWh
in the channel MWh.The overall heat quantity results from
the sum of both values.
The accumulated heat quantity can be reset. As soon as one
of the display channels of the heat quantity is selected, the
symbol is permanently shown on the display.
ÎÎ Press button SET (3) for about two seconds in order
to access the RESET mode of the counter.
The display symbol
will flash and the heat quantity
value will be set to 0.
ÎÎ In order to finish this process, press the
button
to confirm.
In order to interrupt the RESET process, no button should
be pressed for about five seconds. The controller automatically returns to the display mode.
CDIS
Countdown of monitoring
period
Display range:
0 ... 30:0 ... 24 (dd:hh)
If the thermal disinfection option (OTD) is activated and
the monitoring period is in progress, the remaining monitoring time will be displayed as CDIS (in days and hours)
and counted backwards.
SDIS
Starting time display
Display range:
00:00 ... 24:00 (hh:mm)
If the thermal disinfection option (OTD) is activated and
a starting delay time has been adjusted, the adjusted delay
time is displayed (flashing) in this channel.
DDIS
Heating period display
Display range:
00:00 ... 24:00 (hh:mm)
If the thermal disinfection option (OTD) is activated and
the heating period is in progress, the remaining time of the
heating period is displayed (in hours and minutes) in this
channel, counting backwards.
Time
Indicates the actual time.
button for two seconds in order to adjust
Press the
the hours. Press it again in order to adjust the minutes. Set
the time by pressing buttons 1 and 2. Press the
button
in order to save the adjustment.
Operating hours counter
The operating hours counter accumulates the solar operating hours of the respective relay (h P / h P1 / h P2). Full
hours are displayed.
The accumulated operating hours can be set back to zero.
As soon as one operating hours channel is selected, the
is displayed.
symbol
ÎÎ In order to access the RESET-mode of the counter,
press the SET button (3) for approx. two seconds.
The display symbol
will flash and the operating hours
will be set to 0.
ÎÎ Confirm the reset with the
button in order to
finish the reset.
In order to interrupt the RESET-process, do not press a
button for about five seconds. The display returns to the
display mode.
h P / h P1 / h P2:
Operating hours counter
Display channel
| 38
© Viessmann 5443203
Indication of current pump speed
SCU224
4.2Adjustment channels
System layout selection
Arr:
System layout selection.
Adjustment range:1 ... 10
Factory setting: 1
Security enquiry:
In this channel, a pre-defined system layout can be selected.
Each system layout has a set of pre-programmed settings
that can be individually changed.
If the system layout selection is changed later on, all adjustments made in the other channels will be lost. Therefore,
changing the system layout is always followed by a security
enquiry.
Only confirm the security enquiry if you are sure that
you wish to change the system layout selection!
ÎÎ To confirm the security enquiry, press button 3
∆T-regulation
DT O / DT1O / DT2O /
DT3O:
Switch-on temperature diff.
Adjustment range:2.0 ... 40.0°Ra
[1.0 ... 20.0 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 12.0°Ra
[6.0 K]
Note:
The switch-on temperature difference must be
at least 1 °Ra [0.5 K] higher than the switch-off
tempe­rature ­difference.
DT F / DT1F / DT2F / DT3F:
Switch-off temperature d
­ iff.
Adjustment range:1.0 ... 39.0°Ra
[0.5 ... 19.5 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 8.0°Ra
[4.0 K]
Note:
When the drainback option ODB is activated,
the temperature differences DT O, DT F and
DT S are set to a fixed adjustment:
DT O =
20 °Ra [10 K]
DT F
=
8 °Ra [4 K]
DT S
=
30 °Ra [15 K]
Previous adjustments made in these channels will
be overridden and may have to be entered again if
ODB is deactivated later on.
Pump speed control
Note:
For pump speed control, the operation mode
of the corresponding relay must be set to Auto
(adjustment channel MAN1 / MAN2)
DT S / DT1S / DT2S / DT3S:
Nominal temperature difference
Adjustment range:3.0 ... 60.0 °Ra
[1.5 ... 30.0 K]
in steps of 1 °Ra [0.5 K]
Factory setting: 20.0 °Ra
[10.0 K]
RIS / RIS1 / RIS2 / RIS3:
Rise
Adjustment range:
2 ... 40 °Ra
[1 ... 20 K]
in steps of 2 °Ra [1 K]
Factory setting: 4 °Ra [2 K]
Minimum pump speed
© Viessmann 5443203
The controller works as a standard differential controller. If
the switch-on difference is reached, the pump is activated.
When the temperature difference falls below the adjusted
switch-off temperature difference, the respective relay
switches off.
nMN, n1MN, n2MN:
Pump speed control
Adjustment range:
30 ... 100
in steps of 5 %
Factory setting: 30
When the switch-on temperature difference is reached,
the pump is activated at full speed for 10 seconds.Then, the
speed is reduced to the minimum pump speed value (factory
setting = 30 %).
If the temperature difference reaches the adjusted nominal
temperature difference, the pump speed increases by one
step (10 %). If the difference increases by the adjustable rise
value, the pump speed increases by 10 % respectively until the
maximum pump speed of 100 % is reached.The response of
the controller can be adapted via the parameter “Rise”.
Note:
The nominal temperature difference must be
at least 1 °Ra [0.5 K] higher than the switch-on
tempe­rature ­difference.
A relative minimum pump speed can be allocated to the
outputs R1 and R2 via the adjustment channels nMN,
n1MN and n2MN.
Note:
When loads which are not speed-controlled (e.g.
valves) are used, the value must be set to 100 % in
order to deactivate pump speed control.
39 |
SCU224
Maximum tank temperature
S MX / S1MX / S2MX:
Maximum tank temp.
Adjustment range:
40 ... 200 °F
[4 ... 95 °C]
Arr 10:
40 ... 190 °F
[4 ... 90 °C]
in steps of 2 °Ra [1 K]
Factory setting:140 °F [60 °C]
Collector temperature limitation
Emergency shutdown of the collector
EM / EM1 / EM2:
Collector temperature limitation
Adjustment range:
170 ... 390 °F
[80 ... 200 °C]
in steps of 2 °Ra [1 K]
Factory setting:
270 °F [130 °C]
Once the adjusted maximum temperature is exceeded,
the solar pump is switched off and further loading of the
tank is prevented to reduce scald risk or system damage. A
fixed hysteresis of 4 °Ra [2 K] is set for the maximum tank
temperature.
When the temperature at the corresponding sensor exceeds
the adjusted maximum tank temperature, the symbol is
shown on the display.
Note:
If the collector cooling or the system cooling
function is activated, the adjusted tank temperature may be overridden. In order to prevent
system damage, the controller is also equipped
with a non-adjustable emergency shutdown if the
tank reaches 200 °F [95 °C].
If the adjusted collector emergency shutdown temperature
(EM / EM1 / EM2) is exceeded, the controller switches off
the solar pump (R1 / R2) in order to protect the system
against overheating (collector emergency shutdown).
A hysteresis of 20 °Ra [10 K] is set for the collector
temperature limitation.While the collector is in emergency
(flashing) is shown on the display.
shutdown,
Note:
If the drainback option ODB is activated,
the adjustment range of EM is changed to
170 ... 250 °F [80 ... 120°C].The factory setting
in that case is 200 °F [95 °C].
Danger of injury and system damage through pressure surges!
If water is used as a heat transfer
medium in a pressure-less system,
the water will start boiling at 212 °F
[100 °C].
ÎÎ If a pressure-less drainback
system is used with water as a
heat transfer medium, do not
adjust the collector temperature limitation EM to more
than 200 °F [95 °C]!
© Viessmann 5443203
WARNING!
| 40
SCU224
Cooling functions
In the following the three cooling functions – collector
cooling, system cooling and tank cooling – are described
in detail. The following notes are valid for all three cooling
functions:
Note:
The cooling functions will not become active as
long as solar loading is possible.
Note:
In 2-tank-systems, the cooling functions will only
affect tank 1, respectively the bottom area of the
tank (such as in Arr = 4).
Collector cooling function
OCC / OCC1 / OCC2:
Option collector cooling
Adjustment range: OFF / ON
Factory setting: OFF
CMX / CMX1 / CMX2:
Maximum collector temp.
Adjustment range:
150 ... 320 °F
[70 ... 160 °C]
in steps of 1 °Ra [1 K]
Factory setting:
230 °F [110 °C]
When the collector cooling function is activated, the controller
aims to keep the collector at an operational temperature.
When the adjusted maximum tank temperature is reached,
solar loading stops. If the collector temperature increases
to the adjusted maximum collector temperature, the solar
pump is activated until the collector temperature falls at least
10 °Ra [5 K] below the maximum collector temperature.The
tank temperature may increase (subordinate active maximum
tank temperature), but only up to 200°F [95 °C] (emergency
shutdown of the tank).
If the collector cooling function is active, and
(flashing)
is shown on the display.
Note:
This function will only be available if the system
cooling function (OSYC) is deactivated.
Note:
In system layout 10, the parameter CMX is
available without the OCC function. In system
layout 10, CMX is used to set the activation temperature for the heat dump function. No other
switch-on condition is needed in that case.
System cooling function
© Viessmann 5443203
OSYC:
Option system cooling
Adjustment range: OFF / ON
Factory setting: OFF
DTCO:
Switch-on temperature diff.
Adjustment range:
2.0 ... 60.0 °Ra
[1.0 ... 30.0 K]
in steps of 1 °Ra [0.5 K]
Factory setting:
40.0°Ra [20.0 K]
DTCF:
Switch-off temperature d
­ iff.
Adjustment range:
1.0 ... 59.0 °Ra
[0.5 ... 29.5 K]
in steps of 1 °Ra [0.5 K]
Factory setting:
30.0 °Ra [15.0 K]
When the system cooling function is activated, the controller aims to keep the solar system operational for a longer
time.The function overrides the maximum tank temperature
to provide thermal relief of the collector field and the heat
transfer fluid on hot days.
If the tank temperature is higher than the maximum tank
temperature (S MX / S1MX) and the switch-on temperature difference DTCO is reached, the solar system remains
activated. Solar loading is continued until either the tank
temperature reaches 200 °F [95 °C] (emergency shutdown
of the tank), the temperature difference falls below the adjusted value DTCF or the collector emergency shutdown
temperature EM is reached.
(flashing)
If the system cooling function is active, and
is shown on the display.
Note:
This function will only be available if the collector
cooling function (OCC) is deactivated.
41 |
SCU224
OSTC:
Tank cooling option
Adjustment range: OFF / ON
Factory setting: OFF
OHOL:
Holiday cooling option
Adjustment range: OFF / ON
Factory setting: OFF
THOL:
Holiday cooling temperature
Adjustment range:
70 ... 175 °F
[20 ... 80 °C]
in steps of 1 °F [1 °C]
Factory setting:
110 °F [40 °C]
Collector minimum limitation option
OCN / OCN1 / OCN2:
Collector minimum limitation
Adjustment range: OFF / ON
Factory setting: OFF
CMN / CMN1 / CMN2:
Collector minimum temp.
Adjustment range:
50 ...190 °F
[10 ... 90 °C]
in steps of 1 °Ra [0.5 K]
Factory setting:
50 °F [10 °C]
Antifreeze option
OCF / OCF1 / OCF2:
Antifreeze function
Adjustment range: OFF / ON
Factory setting: OFF
CFR / CFR1 / CFR2:
Antifreeze temperature
Adjustment range:
-40.0 ... +50.0 °F
[-40.0 ... +10.0 °C]
in steps of 1 °Ra [0.5 K]
Factory setting:
40.0 °F [4.0 °C]
| 42
When the tank cooling function is activated, the controller
aims to cool down the tank during the night in order to
prepare it for solar loading on the following day.
If the adjusted maximum tank temperature (S MX / S1MX)
is exceeded and the collector temperature falls below the
tank temperature, the system will be reactivated in order
to cool down the tank. Cooling will continue until the tank
temperature has fallen below the adjusted maximum tank
temperature (S MX / S1MX) again. A fixed hysteresis of
4 °Ra [2 K] is set for this function.
Reference threshold temperature differences for the tank
cooling function are DT O and DT F.
If no DHW consumption is expected for a longer period
of time, the additional holiday cooling option OHOL can
be activated in order to extend the tank cooling function.
The adjustable temperature THOL then replaces the
maximum tank temperature (S MX / S1MX) as a switch-off
temperature for the tank cooling function.
When the holiday cooling function is activated,
and
(flashing) are shown on the display.
While the holiday cooling function is active, ,
and
(flashing) are shown on the display.
If the collector minimum limitation option is activated,
the pump (R1 / R2) is only switched on if the adjustable
collector minimum temperature is exceeded.The minimum
temperature prevents the pump from being switched on too
often at low collector temperatures. A fixed hysteresis of
10 °Ra [5 °K] is set for this function
If the collector minimum limitation is active,
(flashing) is
shown on the display.
Note:
If OSTC or OCF is active, the collector minimum
function will be overridden. In that case, the
collector temperature may fall below CMN.
The antifreeze function activates the loading circuit between
the collector and the tank when the temperature falls below
the adjusted antifreeze temperature. This will protect the
fluid against freezing or coagulating. If the adjusted antifreeze
temperature is exceeded by 2 °Ra [1 K], the loading circuit
will be deactivated.
When the antifreeze function is activated,
is shown on
the display. If the antifreeze function is active,
and
(flashing) are shown on the display.
Note:
Since this function uses the limited heat quantity
of the tank, the antifreeze function should be
used in regions with few days of temperatures
around the freezing point.
The antifreeze function will be suppressed if the
tank temperature falls below 40 °F [5 °C] in
order to protect the tank from frost damage.
© Viessmann 5443203
Tank cooling function
SCU224
The SCU224 priority logic
Note:
Priority logic can be used in multi-tank system
layouts only (Arr = 4, 5, 6).
PRIO:
Loading priority
Adjustment range:
SE 1, SE 2, Su 1, Su 2, 0, 1, 2
Factory setting:
Arr 4: 2
Arr 5, 6:1
Note:
If the priority is set to Su 1 or Su 2, solar
loading of the subordinate tank will be aborted
at once if the temperature in the priority tank
(tank 1 for Su 1, tank 2 for Su 2) falls below the
adjusted maximum temperature. If, in that case,
the temperature difference between the priority
tank and the collector is not sufficiently high,
solar loading will be stopped completely.
Spreaded loading temperature difference
(only available if PRIO is set to SE 1 or SE 2)
DTSE:
Spread temperature difference
Adjustment range:
40 ... 160 °Ra
[20 ... 90 K]
in steps of 1 °Ra [1 K]
Factory setting: 70 °Ra [40 K]
Tank sequence control
(only available if priority is set to SE 1, SE 2, 1 or 2)
tLB:
Loading break time
Adjustment range: 1 ... 30 min
Factory setting: 2 min
© Viessmann 5443203
tRUN:
Loading runtime
Adjustment range: 1 ... 30 min
Factory setting: 15 min
If a multi-tank system layout has been chosen, the priority
logic determines how the heat is divided between the
tanks. Different types of priority logic are adjustable:
•• spreaded loading (SE 1 and SE 2)
•• successive loading (Su 1 and Su 2)
•• parallel loading (0)
•• tank sequence control (1 and 2)
If priority SE 1 or SE 2 (only available in Arr 6) is
adjusted, the subordinate tank will be loaded in parallel if
the temperature difference between the collector and the
priority tank (tank 1 for SE 1, tank 2 for SE 2) exceeds the
adjusted value DTSE and the subordinate tank has not
reached its maximum temperature.
Parallel loading will stop as soon as the temperature
difference between the collector and the priority tank falls
4 °Ra [2 K] below DTSE or the subordinate tank reaches
its maximum temperature.
If priority Su 1 or Su 2 is adjusted, the tanks are loaded
successively. The subordinate tank will only be loaded if the
priority tank (tank 1 for Su 1, tank 2 for Su 2) has reached
its adjusted maximum temperature (S1MX or S2MX).
If priority 0 is adjusted and the switch-on conditions are
fulfilled for both tanks, the tanks are loaded in parallel
(Arr 6), resp. in an oscillating loading (Arr 4, 5) beginning
with the tank with the lowest temperature. In an oscillating
loading, solar loading will switch from one tank to the other
in steps of 10 °Ra [5 K] temperature difference between
the tanks.
If priority 1 / 2 is adjusted, tank sequence control will
be activated (see below) with the corresponding tank as
priority tank.
Tank sequence control will be activated when PRIO is set
to SE 1, SE 2, 1 or 2.
If the priority tank cannot be loaded, the subordinate tank
is checked. If useful heat can be added, it will be loaded
for the “loading runtime time” (tRUN - factory setting
15 min.) After this, the loading process stops and the
controller monitors the increase in collector temperature during the loading break time tLB. If it increases by
4° Ra [2 K], the break time timer starts again to allow the
collector to gain more heat. If the collector temperature
does not increase sufficiently, the subordinate tank will be
loaded again for the tRUN time as before.
As soon as the switch-on condition of the priority tank is
fulfilled, it will be loaded. If the switch-on condition of the
priority tank is not fulfilled, loading of the second tank will be
continued. If the priority tank reaches its maximum temperature, sequence controlled loading will not be carried out.
If tank sequence control is active and the system switches
to load the priority tank, the parameter tLB also acts as a
stabilization timer, during which the switch-off condition DT F
is ignored while the system operation stabilizes.
43 |
SCU224
Evacuated tube collector function
TCST:
Tube collector function
starting time
Adjustment range:
00:00 ... 23:45
in steps of 00:15
Factory setting: 07:00
TCEN:
Tube collector function
ending time
Adjustment range:
00:00 ... 23:45
in steps of 00:15
Factory setting: 19:00
TCRU:
Tube collector function
runtime
Adjustment range: 5 ... 500 s
in steps of 5 s
Factory setting: 30 s
TCIN:
Tube collector function
standstill interval
Adjustment range: 1 ... 60 min
in steps of 1 min
Factory setting: 30 min
Energy metering
OHQM: Energy metering
Adjustment range: OFF / ON
Factory setting: OFF
FMAX: Flow rate in l/min
Adjustment range: 0.5 ... 100.0
in steps of 0.5
Factory setting: 6.0
MEDT: Heat transfer fluid
Adjustment range: 0 ... 3
Factory setting: 1
MED%: Antifreeze ratio
in Vol-% (MED% is hidden
when MEDT 0 or 3 is used.)
Adjustment range: 20 ... 70
in steps of 1 %
Factory setting: 45
| 44
This function helps overcome the disadvantages caused by
the non-ideal sensor position with some tube collectors.
This function is not required with the Vitosol 300-T, but is
required for the Vitosol 200-T.
This function operates within an adjusted time frame (beginning at TCST and ending at TCEN). It activates the
collector circuit pump for an adjustable runtime (TCRU)
between adjustable standstill intervals (TCIN) in order to
compensate for the delayed temperature measurement.
If the runtime TCRU is set to more than ten seconds, the
pump will be run at 100 % for the first ten seconds of the
runtime. For the remaining runtime, the pump will be run
at the adjusted minimum speed nMN.
If the collector sensor is defective or the collector is blocked,
this function is suppressed or switched off.
In system layout 7 (Arr = 7) both collectors are operated
independently from each other by means of this function. If
the tank is being loaded by one collector, the other one is
nevertheless operated after the adjusted standstill time.
Note:
If the drainback option ODB is activated, TCRU
will not be available. In that case, the runtime
is determined by the parameters tFLL and
tSTB.
If OHQM is activated, the heat quantity gained can be calculated and displayed. Energy metering is possible on Arr. 1, 3,
4, 5 and 10 if a flowmeter is used.To enable energy metering,
proceed as follows:
ÎÎ Read the flow rate (l/min) from the flowmeter at maximum pump speed and adjust it in the FMAX channel
ÎÎ Adjust the heat transfer fluid and the concentration of
the antifreeze in the channels MEDT and MED%.
Note:
When using Tyfocor HTL set MEDT to 1 and
MED% to 50.
Heat transfer fluid:
0 : Water
1 : Propylene glycol
2 : Ethylene glycol
3 : Tyfocor® LS / G-LS
Note:
If the system layout 10 has been selected and
OHQM is activated, energy metering will be
interrupted when the 3-way-valve switches to
the heat dump.
© Viessmann 5443203
O TC:
Evacuated tube collector
function
Adjustment range: OFF / ON
Factory setting: OFF
SCU224
Drainback option
Note:
Viessmann Vitosol collectors cannot be used in
drainback systems.
Note:
A drainback system layout requires additional
components such as a holding tank.The drainback
option should only be activated if all components
required are properly installed.
Note:
The drainback option is only available in system
layouts with one tank and one collector (Arr 1,
2, 3, 8 and 9).
ODB:
Drainback option
Adjustment range: OFF / ON
Factory setting: OFF
Note:
When the drainback option ODB is activated, the
cooling functions OCC, OSYC and OSTC as well
as the antifreeze function OCF are not available.
If OCC, OSYC, OSTC or OCF have already
been activated before, they will be deactivated
again as soon as ODB is activated.They will remain
deactivated, even if ODB is deactivated later on.
A drainback system permits the heat transfer fluid to drain
back into the holding tank when solar energy is not collected. The drainback option will initiate the filling of the
system when solar loading begins.
If the drainback option ODB is activated, the pump will
operate at 100 % speed for the adjusted filling time tFLL
in order to fill the system with fluid from the holding tank.
After tFLL, pump speed will go down to the adjusted
minimum pump speed nMn. The switch-off conditions will
then be ignored for the stabilization time tSTB in order to
avoid the system from shutting down prematurely.
If the function is activated, the menu items described in the
following (tDTO, tFLL and tSTB) have to be adjusted:
Note:
When the drainback option ODB is activated,
the temperature differences DT O, DT F and
DT S are set to a fixed adjustment. Additionally,
the adjustment range and the factory setting of
the collector emergency shutdown temperature
EM changes (see the corresponding channel
descriptions for further information).
Previous adjustments made in these channels will
be overridden and have to be entered again if
ODB is deactivated later on.
Time period - switch-on conditions
tDTO:
Time period switch-on conditions
Adjustment range: 1 ... 100 s
in steps of 1 s
Factory setting: 60 s
Filling time
tFLL:
Filling time
Adjustment range:
1.0 ... 30.0 min
in steps of 0.5 min
Factory setting: 5.0 min
© Viessmann 5443203
Stabilization
tSTB:
Stabilization
Adjustment range:
1.0 ... 15.0 min
in steps of 0.5 min
Factory setting: 2.0 min
Booster function option
OBST:
Booster function
Adjustment range: ON / OFF
Factory setting: OFF
The parameter tDTO is used for adjusting the time period
during which the switch-on condition DT O must be permanentely fulfilled.
The filling time can be adjusted using the parameter tFLL.
During this period, the pump runs at 100 % speed.
The parameter tSTB is used for adjusting the time period
during which the switch-off condition DT F will be ignored
after the filling time has ended.
This function is used for switching on a second pump when
filling the solar system. When solar loading starts, R2 is energized in parallel to R1. After the filling time (tFLL) has ended,
R2 is switched off.
Note:
The booster function is available in system layout 1
(Arr = 1) only.
The booster function will only be available if the
drainback option has been activated.
45 |
SCU224
Operating mode
MAN1 / MAN2:
Operating mode
Adjustment range:
OFF, Auto, ON
Factory setting: Auto
For control and service work, the operating mode of the
controller can be manually adjusted. For this purpose, select
the adjustment value MAN1, MAN2 in which the following
adjustments can be made:
• MAN1 / MAN2
Operating mode
OFF
Auto
:
:
relay off
(flashing) +
relay in automatic operation
ON
:
relay on
(flashing) +
Note:
Always adjust the operating mode back to
“Auto” when the control and service work is
completed. Normal operation is not possible in
manual mode.
Language
LANG:
Language selection
Selection: dE, En
Factory setting: En
The menu language can be adjusted in this channel.
• dE : German
• En : English
Unit
UNIT:
Temperature unit selection
Selection: °F, °C
Factory setting: °C
In this adjustment channel, the display unit for temperatures
and temperature differences can be chosen.The unit can be
switched between °C / K and °F / °Ra during operation.
Temperatures and temperature differences in °F and °Ra
are displayed without units. If the indication is set to °C, the
units are displayed with the values.
Reset
RESE
Reset function
By using the reset function, all adjustments will be set back
to the factory settings.
ÎÎ To initiate a reset, press button 3
Any previous adjustments will be lost. Therefore, initiating the reset function is always followed by a security
enquiry.
Only confirm the security enquiry if you are sure
that you wish to reset all adjustments to the factory
settings!
Security enquiry:
ÎÎ To confirm the security enquiry, press button 3
© Viessmann 5443203
Note:
Whenever a reset has been completed, the
controller runs the commissioning menu again
(see chap. 3).
| 46
SCU224
5. Troubleshooting
fuse
In the case of an error, a message is shown on the display
of the controller:
Warning symbols
Operating control lamp
VBus terminals
®
sensor terminals
ground
terminals
load terminals
power supply
terminals
Operating control lamp flashes red. On the display the
symbols
and
appear.
Sensor defect. An error code instead of
a temperature is displayed in the sensor
display channel.
888.8
Short circuit.
Check cable.
Disconnected Pt1000 temperature sensors can be checked with an ohmmeter. In
the following table, the resistance values
with the corresponding temperatures are
shown.
© Viessmann 5443203
Check the power supply. Is it disconnected?
no
- 88.8
Cable broken.
Check cable.
Operating control lamp off.
°C
°F
Ω
°C
°F
Ω
-10
-5
0
5
10
15
20
25
30
35
40
45
50
14
23
32
41
50
59
68
77
86
95
104
113
122
961
980
1000
1019
1039
1058
1078
1097
1117
1136
1155
1175
1194
55
60
65
70
75
80
85
90
95
100
105
110
115
131
140
149
158
167
176
185
194
203
212
221
230
239
1213
1232
1252
1271
1290
1309
1328
1347
1366
1385
1404
1423
1442
The fuse of the controller
could be blown. It can be
replaced after the front
cover has been removed
(spare fuse is enclosed in
the accessory bag).
yes
Check the supply line and
reconnect it.
Resistance values of the Pt1000-sensors
47 |
SCU224
5.1Various:
Pump is overheated, but no heat transfer from the
­collector to the tank, flow and return have the same temperature; perhaps also air / gas bubbles in the lines.
Pump starts for a short moment, switches off, switches
on again, etc.
Air in the system?
Temperature difference
at the controller too
small?
no
yes
Is the collector circuit
blocked at the dirt trap?
Air in the system; in­crease
the system pressure to at
least static primary pres­
sure plus 7. 25 psi (0.5 bar);
if necessary continue to
increase pressure; switch
the pump off and on for a
short time.
no
no
Wrong position of collector sensors?
no
yes
yes
Change ∆Ton and ∆Toff
correspondingly. Problem
solved?
yes
Clean the dirt trap
Plausibility control of
the option tube collector special function
yes
o.k.
Mount the collector sensor at solar flow (warmest
collector output); use sensor well of the respective
collector.
Pump starts up very late
The temperature difference between tank and collector
increases enormously during operation; the collector circuit cannot dissipate the heat.
Switch-on temperature
difference ∆Ton to large?
Collector circuit pump
defective?
no
yes
Change ∆Ton and ∆Toff
correspondingly.
yes
Check / replace it
Heat exchanger calcified?
Non-ideal position of the collector sensor (e.g. flatscrew
sensor instead of sensor in
sensor wells)?
yes
no
no
yes
Decalcify it
Activate tube collector
function if necessary.
Heat exchanger blocked?
o.k.
no
yes
Clean it
yes
| 48
Replace with correctly
sized one.
© Viessmann 5443203
Heat exchanger too
small?
SCU224
a
Tanks cool down at night
b
Control the non-return
valve in warm water circulation - o.k.
Collector circuit pump
runs during the night?
no
yes
Collector temperature is
at night higher than the
outdoor temperature
no
yes
Sufficient tank insulation?
yes
no
Check controller:
Manual operation active?
Tube collector function
active? Tank cooling
or antifreeze function
active?
Check the check valve in
the flow and the return
pipe with regard to the
functional efficiency.
Increase insulation.
no
Replace insulation or increase it.
Are the tank connections
insulated?
yes
no
Warm water outflow
upwards?
no
yes
Insulate the connections.
Change connection and
let the water flow hori­
zontally or through a siphon (downwards); less
tank losses now ?
no
yes
o.k.
Does the warm water
circulation run for a very
long time?
no
yes
Circulation pump and
blocking valve should be
switched off for one night;
less tank losses?
© Viessmann 5443203
yes
no
Use the circulation pump
with timer and switch-off
thermostat (energy efficient circulation).
Check whether the pumps
of the backup heating circuit run at night; check
whether the non-return
valve is defective; problem
solved ?
The thermosiphoning in
the circulation line is too
strong; insert a stronger
valve in the non-return valve or an electrical 2-port
valve behind the circulation pump; the 2-port valve
is open when the pump is
activated, otherwise it is
closed; connect pump and
2-port valve electrically in
parallel; activate the circulation again
b
Is the control lamp (LED)
illuminated?
yes
Clean or replace it
no
The adjusted temperature
difference for starting the
pump is to high; choose a
value which makes more
sense.
Is the pump stuck?
yes
yes
Turn the pump shaft using
a screwdriver; now passable?
no
Are the controller fuses
o.k. ?
no
Replace fuses.
o.k.
yes
Is the pump current
enabled by the controller?
no
There is no current; check
fuses / replace them and
check power supply.
no
Does the pump start up
in manual operation?
yes
no
a
no
The solar circuit pump does not work, although the collector is considerably warmer than the tank.
Insulation close enough
to the tank?
yes
yes
Further pumps which are
connected to the solar
tank must also be checked.
Pump is defective - replace it
yes
Controller might be defective - replace it or contact
the distributor.
49 |
SCU224
6. Accessories
Smart Display SD3
The Smart Display is designed for simple connection to controllers with VBus®. It is used
for visualizing data issued by the controller: collector temperature, storage temperature
and energy yield of the solar thermal system. The use of high-efficient LEDs and filter glass
assures a high optical brilliance and good readability even in poor visibility conditions and
from a larger distance. An additional power supply is not required.
DL2 Datalogger
This additional module enables the acquisition and storage of large amounts of data (such
as measuring and balance values of the solar system) over a long period of time. The DL2
can be configured and read-out with a standard internet browser via its integrated web
interface. For transmission of the data stored in the internal memory of the DL2 to a PC,
an SD card can be used.
The DL2 is appropriate for all controllers with VBus®. It can be connected directly to a
PC or router for remote access and thus enables comfortable system monitoring for yield
monitoring or for diagnostics of faults.
VBus® / USB interface adapter
© Viessmann 5443203
The new VBus® / USB interface adapter is the interface between the controller and a
personal computer. With its standard mini-USB port it enables a fast transmission of
system data via the VBus® for processing, visualizing and archiving. A full version of the
ServiceCenter software is included.
| 50
© Viessmann 5443203
SCU224
Notes
51 |
Viessmann Manufacturing Company (U.S.) Inc.
45 Access Rd.
Warwick, RI 02886
Telephone: (401) 732-0667
Fax: (401) 732-0590
Internet: www.viessmann-us.com
E-Mail: info@viessmann-us.com
Viessmann Manufacturing Company Inc.
750 McMurray Rd.
Waterloo, Ontario N2V 2G5
Telephone: (519) 885-6300
Fax: (519) 885-0887
Internet: www.viessmann.ca
E-Mail: mail@viessmann.ca
Important notice:
The texts and drawings in this manual are correct to the
best of our knowledge. As faults can never be excluded,
please note: Your own calculations and plans, under con­sider­
ation of the current standards should only be basis for your
projects.We do not offer a guarantee for the completeness of
the drawings and texts of this manual - they only represent
some examples. They can only be used at your own risk.
No liability is assumed for incorrect, incomplete or false
information and / or any resulting damages.
Reprinting / copying
This mounting- and operation manual including all parts is
copyrighted. Another use outside the copyright requires the
approval of Viessmann Manufacturing Company Inc.. This especially applies for copies, translations, microfilms and the
storage into electronic systems. Editor:Viessmann Manufacturing Company Inc.
Please note:
The design and the specifications can be changed without prior notice.
The illustrations may differ from the original product.
| 52
© Viessmann 5443203
SCU224