Hoval TopGas 30, TopGas 35, TopGas 45, TopGas 50, TopGas 60 Technical Information Installation Instructions

EN

Subject to modifi cations

Hoval products must be installed and commis­sioned only by appropriately qualifi ed experts.
These instructions are intended exclusively for
the specialist. Electrical installations may only
be carried out by a qualifi ed electrician.

Technical information
Installation instructions

4 205 254 / 03 - 05/10

Gas condensing boiler
TopGas® (30,35,45,50,60)
for natural and liquid gas

Wall-mounted gas boilers TopGas® (30,35,45,
50,60) according to DIN 4702, DIN EN 483 and
DIN EN 677 are suitable and approved as heat
producers for hot water heating systems with
a permissible flow temperature of up to 85°C).
They are designed for a flexibly reduced opera­tion in heating systems according.

Rated output levels at 40/30°C and
natural gas

5/6-TopGas

®

(30) 6,8 - 30,1 kW
5/6-TopGas® (35) 6,8 - 35,0 kW
5/6-TopGas® (45) 11,1 - 45,0 kW
5/6-TopGas® (50) 12,8 - 52,9 kW
5/6-TopGas® (60) 12,8 - 60,7 kW

2

4 205 254 / 03

Table of contents

1. Important Information ..........................................................................................................4

1.1 Symbols ...................................................................................................................................................4

1.2 Guarantee ................................................................................................................................................4

1.3 Other instructions ................................................................................................................................... 4

1.4 Safety instructions .................................................................................................................................. 4

1.5 Regulations, official approvals .............................................................................................................. 5

1.6 Transport and storage ............................................................................................................................ 5

2. Technical details .................................................................................................................. 6

2.1 Technical Data ......................................................................................................................................... 6

2.2 Dimensions .............................................................................................................................................. 7

2.3 Boiler flow resistance ............................................................................................................................. 8

2.4 Short description of the automatic firing unit BIC 335 ........................................................................ 8

2.5 Control of the boiler ................................................................................................................................ 9

2.6 Adjustable parameters .........................................................................................................................11

3. Installation .......................................................................................................................... 13

3.1 Description of the Hoval TopGas® .......................................................................................................13

3.1.1 Diaphragm expansion tank......................................................................................................................13

3.1.2 Boiler casing ............................................................................................................................................13

3.1.3 Gas fittings ..............................................................................................................................................13

3.1.4 Automatic gas firing unit and heating controller ......................................................................................13

3.1.5 Heating circulation pump .........................................................................................................................13

3.1.6 Hot water supply .....................................................................................................................................13

3.1.7 Scope of supply .......................................................................................................................................13

3.1.8 TopGas® component designation ............................................................................................................14

3.2 Boiler installation room ........................................................................................................................ 15

3.3 Installing the boiler ...............................................................................................................................15

3.4 Hydraulic connection ............................................................................................................................15

3.4.1 Protection planning guidelines for the hydraulic connection ...................................................................15

3.4.2 Boil-dry safeguard ................................................................................................................................... 15

3.4.3 Gravity brake ........................................................................................................................................... 15

3.4.4 Minimum flow rate ................................................................................................................................... 15

3.4.5 To be provided by customer ....................................................................................................................16

3.4.6 Hydraulic interconnection ........................................................................................................................ 16

3.5 Flue gas connection, chimney and condensate pipeline .................................................................. 17

3.5.1 Waste gas pipelines in compliance with building construction law .......................................................... 17

3.5.2 Project planning guidelines for exhaust gas systems .............................................................................. 17

3.5.3 Installation examples for room-air-dependent operation ......................................................................... 18

3.5.4 Exhaust gas system for room-air-independent operation........................................................................19

3.5.5 Attic heating center .................................................................................................................................19

3.5.6 Wall penetration ......................................................................................................................................19

3.5.7 Connection of pipelines ........................................................................................................................... 20

3.5.8 Condensate draining and neutralisation .................................................................................................. 20

3.5.9 Gas connection .......................................................................................................................................20

3.6 Electrical connection ............................................................................................................................ 20

3.6.1 Electrical connection regulations............................................................................................................. 20

3.6.2 Electrical connection (grid) 230 V, 50 Hz................................................................................................. 21

3.6.3 Boiler control / electrical connection diagram .......................................................................................... 21

3.6.4 Connection of the heating controller .......................................................................................................21

3.6.4.1 TopTronic® RS-OT ......................................................................................................................................................21

3.6.4.2 TopTronic® T/N ...........................................................................................................................................................21

3

4 205 254 / 03 Table of contents

4. Commissioning .................................................................................................................. 21

4.1 Setting the control ................................................................................................................................21

4.2 Water quality .......................................................................................................................................... 21

4.2.1 Heating water .......................................................................................................................................... 21

4.3 Filling and replacement water .............................................................................................................. 22

4.3.1 Filling up the system ...............................................................................................................................23

4.3.2 Gas adjustment ....................................................................................................................................... 23

4.3.3 Bleeding the gas pipeline ........................................................................................................................ 23

4.3.4 Commissioning ........................................................................................................................................ 23

4.3.5 Gas inlet pressure ................................................................................................................................... 23

4.3.6 Gas fitting ................................................................................................................................................ 23

4.3.7 Setting the gas flow rate CO2 (O2) and measurement of NOx/CO content in the flue gas (flue gas

measurement) ......................................................................................................................................... 23

4.3.8 Changing to a different kind of gas .........................................................................................................24

4.4 Handing over to the user ...................................................................................................................... 25

4.4.1 Instruction the user ................................................................................................................................. 25

4.4.2 Checking the water level ......................................................................................................................... 25

4.4.3 Maintenance ............................................................................................................................................ 25

5. Decommissioning .............................................................................................................. 25

6. Maintenance ....................................................................................................................... 26

6.1 Water-side leak check ........................................................................................................................... 26

6.2 Refilling .................................................................................................................................................. 26

6.3 Maintenance includes: .......................................................................................................................... 26

6.4 Cleaning the heat exchanger ...............................................................................................................26

6.5 Function check ...................................................................................................................................... 26

7. Troubleshooting ................................................................................................................. 28

8. Parameter List Automatic Burner BIC 335 ....................................................................... 31

4

4 205 254 / 03Important information

Important Information1.

Symbols1.1

Safety information
(Instructions for the safety and protec-

tion of persons)

Warning information
(Instructions for the protection of the

heating system)

Bold type = Important information

Guarantee1.2

Important Note
Proper functioning is only guaranteed if the
operating instructions are observed and the
boiler is regularly maintained according to the
DVGW (German association of gas and water
management / ÖVGW (Austrian association
of gas and water management), respectively
SVGW (Switzerland association of gas and
water management) directives by an approved
specialist. Troubleshooting and damage repair
caused by contaminated operating media (gas,
water, combustion air), unsuitable chemical ad­ditives to the heating water, incorrect handling,
faulty installation, inadmissible modifications
and damage due to the exercising of force are
not covered by our warranty; the same applies
to corrosion through halogen compounds, e.g.
from spray cans, paints, adhesives, solvents
and cleaning agents.
Hoval gas boilers are only to be installed by ap­proved specialists. No modifications are to be
made to the boilers.

Other instructions1.3

Depending on the model, any further instructions are
enclosed with the individually packed components.

- Adjustment

- Accessories

Further information sources

- Hoval catalogue

- Standards, regulations

Safety instructions1.4

When working on the TopGas® the following points
need to be noted:

If you smell flue gas or gas:

no open fire or sparks, ­do not smoke, ­deflector off the heating system, ­close the gas cock, ­open doors and windows -

The system may only be placed in operation when •
all relevant standards and safety regulations have
been complied with. However, for a trial operation,
at least the following conditions must be satisfied:

- Safety valve installed (closed system)

- Control operative (connected to power supply)

- System filled with water

- Expansion tank connected

- Boiler is connected to the regulation type flue gas
pipeline

- Burner is preset

With maintenance and repair•

- Allow the gas boiler to cool.

- Deflector off the gas boiler and disconnect from
the electrical supply.

- Shut off the gas cock.

- Close the shut-off cocks of the appliance (cold
water, heating flow and return).

- Inappropriate actions on water-carrying parts of
the gas boiler can result in an outflow of hot water
and cause severe burns.

- Replace all removed covers and cladding on
completion of the repair / maintenance work.

- Do not exceed the maximum operating pressure
and temperature of the gas boiler (see identifica­tion plate).

- Open the appliance cocks (cold water, heating
flow and return).

- Open the gas cock.

5

4 205 254 / 03 Important information

and further standards and regulations issued by
CEN, CEN ELEC, DIN, VDE, DVGW, TRD and by
the legislator.

Also to be complied with are the regulations of the
local building authorities, insurance companies and
chimney sweeping operations. When using gas as
a fuel, the regulations of the responsible gas supply
company are also to be complied with and any neces­sary official approval obtained.

The regulations concerning condensate pipe­lines and treatment are subject to the regula­tions of the local water authorities and can
differ from the provisions of the technical
drainage directive ATVM251. Please obtain in­formation on the relevant local regulations.

Transport and storage1.6

Please remove the packing materials and examine
the consignment for correctness, completeness and
possible transport damage.
The appliance is only to be transported and stored
only in its original packing. Interim storage of Hoval
gas boilers is only to take place in weather protected
rooms and only in the original packing. The ambient
conditions for storage must be within the following
limits:

- Air temperature: -10°C - +50°C

- Air humidity: 50 - 85% relative humidity

- no condensation

Regulations, official approvals1.5

The following regulations are to be complied with for
installation and operation, in addition to the recognised
rules of the art:

Germany

DIN EN 12831 Heating systems in buildings - •
Methods for calculating the design heat load
DIN EN 13384 Flue gas systems - Heat and flow •
calculation methods
DIN EN 12828 Heating systems in buildings - Plan-•
ning of hot water heating systems.
VDI 2035 Prevention of damage through corrosion •
and scale formation in hot water heating systems.
Firing regulation for the Federal regions•
DVGW-TRGI 86-96•
Technical regulations of gas supply enterprises•
VDE 0100 for electrical installations and the TAB •
(technical connection conditions of the responsi­ble energy supplier)
ATV data sheet M251•
Accident prevention regulations•

- VBG 1 General regulations

- VBG 4 Electric systems and equipment

Austria

OENORM 12831 Heating systems in buildings - •
Methods for calculating the design heat load
OENORM 13384 Flue gas systems - Heat and •
flow calculation methods
OENORM 12828 Heating systems in buildings - •
Planning of hot water heating systems.
OENORM H5152 Calorific value burner systems.•
OENORM H5195-1 Prevention of damage through •
corrosion
M 7443, (Part 2,3,7) Gas appliances with atmos-•
pheric burners
M 7446, Heat output appliances for gaseous fuels•
M 7457, Heat output appliances with mechanically •
supported premix bat-wing burners
M 7444, Special gas boilers with burners without •
fan
M 7459, Gas appliances with gas-air compound •
controller
ÖVGW TR- Gas•
Technical provisions of the gas suppliers•

Switzerland

SN EN 12831 Heating systems in buildings - Meth-•
ods for calculating the design heat load
SN EN 13384 Flue gas systems - Heat and flow •
calculation methods
SN EN 12828 Heating systems in buildings - Plan-•
ning of hot water heating systems.
Requirements of the VKF Cantonal Fire Insurance •
Association
Fire service regulations•
SVGW directives, gas guiding standard G1•
SNV271020 Aeration and ventilation of the boiler •
installation room
SWKI 88-4 Water treatment for heating, steam and •
air conditioning systems
SWKI 80-2 Technical safety regulations for heating •
systems
KRW Corrosion through halogen compounds•
Procal/FKR Plug-in electrical connections on heat-•
ing boiler and burner
Technical tank regulations TTV 1990•
EKAS - Guideline for liquid gas part 2•

6

4 205 254 / 03

Technical details

Technical details2.

Technical Data2.1

Typ (30) (35) (45) (50) (60)

• Rated heating capacity 80/60°C with natural ga

1

kW 6,0-27,4 6,0-31,8 10,0-41,0 11,7-48,3 11,7-55,3

• Rated heating capacity 40/30°C with natural gas

1

kW 6,8-30,1 6,8-35,0 11,1-45,0 12,8-52,9 12,8-60,7

• Rated heating capacity 80/60°C with propane gas

3

kW 6,2-27,4 6,2-31,9 10,8-41,0 13,1-47,8 13,1-54,9

• Rated heating capacity 40/30°C with propane gas

3

kW 7,0-30,2 7,0-35,2 11,9-45,0 14,1-52,5 14,1-60,3

• Rated thermal loading with natural gas

1

kW 6,4-28,3 6,4-33,0 10,6-42,5 12,2-49,9 12,2-57,3

• Rated thermal loading with propane gas

3

kW 6,6-28,5 6,6-33,2 11,4-42,5 13,6-49,6 13,6-56,9

• Operating pressure, heating max./min. bar 3,0 / 1,0 3,0 / 1,0 3,0 / 1,0 3,0 / 1,0 3,0 / 1,0

• Operating temperature max. °C 85 85 85 85 85

• Boiler water contents l 4,5 4,5 4,5 6,0 6,0

• Minimum water circulation quantity l/h 300 300 350 470 470

• Boiler weight (without water content, incl. body) kg 83 83 83 89 89

• Standard level of utilization 40/30°C % 109,8 109,7 109,3 109,7 109,5

75/60°C % 106,3 106,1 105,8 105,8 105,6

• Standby heat losses at 70°C Watt 92 92 95 115 115

• Standard emission factors Nitrous oxide mg/kWh 30,2 30,2 30,2 35,0 35,0

Carbon dioxide mg/kWh 9,0 9,0 11,2 13,0 13,0

• CO

2

content in flue gas max./min. capacity % 9,0 / 8,8 9,0 / 8,8 9,0 / 8,8 9,0-8,8 9,0 / 8,8

• Dimensions See dimension sheet

• Connections Flow / Return Zoll Rp 1 1/4" Rp 1 1/4" Rp 1 1/4" Rp 1 1/4" Rp 1 1/4"

Gas Zoll R 3/4" R 3/4" R 3/4" R 3/4" R 3/4"
Air / flue gas Ø

mm C80/125 C80/125 C80/125 C80/125 C80/125

• Gas flow pressure min./ max.
Natural gas E/LL mbar 18-50 18-50 18-50 18-50 18-50
Liquid gas mbar 42-57 42-57 42-57 42-57 42-57

• Gas connection values at 0°C / 1013 mbar:
Natural gas E - (Wo = 15,0 kWh/m

3

) Hu = 9,97 m3/h 2,83 3,3 4,3 1,2-5,8 5,8

Natural gas LL- (Wo = 12,4 kWh/m

3

) Hu = 8,57 m3/h 2,84 3,9 5,0 1,4-6,7 6,7

Propane gas

3

(Hu = 25,9 kWh/m3) kg/h 1,09 1,27 1,64 0,5-2,2 2,21

• Operating voltage V/Hz 230/50 230/50 230/50 230/50 230/50

• Control voltage V/Hz 24/50 24/50 24/50 24/50 24/50

• Min./max. wattage Watt 29 / 60 29 / 62 29 / 66 30 / 88 30 / 102

• Standby Watt 13 13 13 13 13

• Type of protection IP 40 40 40 40 40

• Noise level max. (room-air dependent) dB(A) 58 58 60 60 60

• Acoustic pressure level (dependent on assemly)

2

dB(A) 40 - 50 40 - 50 40 - 50 40 - 50 40 - 50

• Condensate quantity (natural gas) at 40 / 30°C l/h 3,1 3,6 4,4 4,4 5,3

• Condansate pH-value ca. 5,5 ca. 5,5 ca. 5,5 ca. 5,5 ca. 5,5

• Flue gas system: requirements, values

Temperature class T120 T120 T120 T120 T120
Type of connection B23, B33, C13x, C33x, C43x, C53x, C63(x), C83x
Flue gas mass flow kg/h 49,5 57,7 74,3 81,4 100
Flue gas temperature T

80/60°C °C 67 69 75 75 79

Flue gas temperature T

40/30°C °C 45 47 52 46 49
Volume flow combustion air Nm3/h 35,4 41,3 53,1 59,4 71,6
Delivery pressure for supply air / flue gas pipeline Pa 90 95 115 120 140

1

The boiler series is tested for EE/H setting. Operation is possible without resetting over the Wobbe coefficient range from 12.0 to 15,0 kWh/m3 with
a factory setting to a Wobbe coefficient of 15,7 kWh/m

3

2

Compare with protection notes .

3

TopGas® is also suitable für propone / butane (liquid gas)-mixtures

7

4 205 254 / 03 Technical details

Dimensions2.2

Distance from the side 50 mm•
Distance from the ceiling dependent on the utilised flue gas pipeline system•
In the front 500 mm•

1 Gas connection R ¾"
2 Heating flow Rp 1¼"
3 Heating return Rp 1¼"
4 Condensate drain ∅ 32
5 LAS flue gas supply air

connection DN 80/125

View from below

Top View Borehole drawing

6 Automatic deaeration
7 Boiler control cover
8 Safety valve
9 KFE ball valve

8

4 205 254 / 03Technical details

Boiler flow resistance2.3

Short description of the automatic fir-2.4
ing unit BIC 335

The automatic firing unit operates both without con­troller (TTT/N) and also without room station (RS­OT). The automatic firing unit comprises the follow­ing functions

- PWM- fan (230V~)

- Modulating operation

- Inputs for Flow sensor
Return sensor
Flue gas sensor
Gas pressure deflector
Air pressure deflector:
(not used)
Water pressure deflector
Safety temperature limiter:
(external flue gas thermo­ stat)
HW-buffer sensor
Outdoor sensor
Locking entry:
(Burner blocking)

- Status exit „Failure“ (invertible by parameter set­ting)

- Three-way-valve control for heating/hot water
or loading pump control (230V~exits); Exit for a
three-way-valve / HW loading pump is invertible
by a parameter.

- Collective electrode for ignition and flame guide
(Ionisation)

- Main gas valve (ev. LPG- valve) / heating room
ventilation accessable

Water-side resistance [mbar]

Flow rate [m

3

/h]

0

50

100

150

200

250

300

350

400

450

500

0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5

Boiler incl.
connection kit

Boiler only

Fuses

On the automatic firing unit theres is a mains fuse.
The breakdown of this fuse (2AT) is noticeable by an
empty display even the main deflector is on.

Ionisation flow

The value of the ionisation flow is noted on the infor­mation level and appears as step 8. The access to
the information level is explained in chapter 2.5.

Interface to display ­OpenTherm- interface (RS-OT, TTT/N) ­RS 232- interface to PC ­Start attempts: 4 ­Safety period: 5 sek ­Ignition period: 5 sek ­Pre-ventilation period: 20 sek ­After-run time main pump / heating pump ­(230V ~): 10 min
After-run time three-way valve / HW-loading pump: ­2 min
Restart locking after a heat demand: 2 min ­Restart locking after a temperature blocking: ­2 min

9

4 205 254 / 03 Technical details

Control of the boiler2.5

Control elements on the boiler control panel / Basic control N4.1

Usually, no settings of the basic control have to be made by the user. All settings have been made
by the installer or by the manufacturer.

Display: temperature

Changing of
the values

Display: Mode

RESET

Fault-clearance (display is
blinking, if there is a failure)

Saving of
the settings

Options, to change settings
(Parmeter) (p.ex. Calorifier
temperature)

ON/OFF Manometer

Function options
(stepwise display option)

Function

Mode indication

Parameter

Indication

Value indication

Meaning, Description

Standby-Mode

Normal position,

Start position

current flow temperature

no indication

0

= Standby, no heat demand, waiting time main gasvalve

1

= Rinsing

2

= Ignition

3

= Burner „on“ in heating operation

4

= Burner „on“ in hot water operation

5

= Air pressure deflector defectiv (no air pressure deflector in use)

6

= Burner „off“ in heating operation
(flow-Temp > flow-temp set point + blockage Offset ZH)

7

= Pump after-run time in heating operation

8

= Pump after-run time in hot water operation

9

= Burner „off“ on hot water operation
(flow-Temp > flow-temp. set point + Par.1 (2AB))

Fr

= Frost protection is activated

Su

= Summer short operation is activated

10

4 205 254 / 03Technical details

Setting of the service codes

For entering the code, press the keys „Mode“ and „Step“ simultaneously. The blinking numeral can be
changed with the „+“ and „-“ –keys. To deflector between the numerals press the „Step“- key. To confirm and
safe the total code press the „Store“- key. After 20 minutes it will be changed into the indication level.

Parameter level (constant point)

The parameter level will be signalised by a constant point behind the second sign.
If none of both keys „+“/“-„ are pressed, “P“ + the parameter number will be shown alternating and then also
the corresponding parameter value. By pressing „+“ or „-“ the parameter value can be changed. To save the
changing press the „Store“- key, which will be confirmed by blinking twice (Wait for blinking before pressing
any further keys!). If the „Store“- key won‘t be pressed, the settings are not saved.

Function

Mode indication

Parameter

Indication

Value indication

Meaning, Description

Informations-Mode

It is possible to read monetary

values from here

Point is blinking

0

e.g. 45°

Current flow temperature (Heating water temperature)

1

e.g. 40°

Current return temperature

2

e.g. 60°

Current temperature in water heater

3

e.g. 3°

Current outdoor temperature

4

e.g. 55°

Current flue gas temperature

5

e.g. 50°

Flow set value in the heating system

6

e.g. 70°

Flow set value in hot water operation

7

e.g. 23 RPM

Fan speed in hundreds

8

e.g. 4 µ A

Ionisation flow

Parameter-Mode

Settings can be changed in this mode.

Point appears

P. 7

60

= Hot water set value if there is no TopTronic® attached.

Procedure:

P. 18

80

= Max. Flow temperature during heating operation

1. Select parameter Mode
(press Mode key 2 x)
Parameter (P.7) and setting appear

alternate

Par. 18

Flow temperature

Outdoor temerature

2. Select parameter to be changed
(Step key)

3. Change setting using + - keys

4. Save (press Store key 1 x)

Automatic return to standby mode in
20 minutes or with Mode key.

Other parameters only with service code

11

4 205 254 / 03 Technical details

Adjustable parameters2.6

Parameter 7 (2AH) – Set point DHW charging temperature –
Using this parameter the reference value for the DHW temperature can be set where there is no room con­trol unit or other regulatory device installed. If a reference value is transmitted via an OT bus, the latter (value
via OT) will always override this parameter.

Parameter 8 (2AI) – Pump after-run time (DHW) –
During the time which can be set using this parameter the pump continues to run after a phase of hot water
demand. The after-run time occurs before a switchover to heating operation as well as before a switchover
to to stand-by mode (to be set at the RS-OT or control unit) or when the firing device is switched OFF. It
also occurs of course when the desired DHW value has been reached and further heating operation is not
required.

Parameter 9 (2AJ) – Legionella protection time –
The boiler is periodically heated to the temperature defined using parameter 2AF for the time period which
can be set using this parameter for protection against legionella infestation. If the parameter value is set to
0 the legionella protection function is deactivated.

Parameter 10 (2AK) – Maximum fan speed in DHW mode –
The parameter defines the maximum rpm value for the fan during DHW operation.

Parameter 18 (2BH)
– Maximum heating temperature (when minimum outside temperature has been reached) –
The value which can be set here determines the flow temperature which is to be achieved when the out­side temperature falls below the value set using parameter 19 (2BI) (minimum outside temperature). (see
diagram 2). If the OT bus sends a reference value to the firing device, this value is limited by the value set
using parameter 18.

Parameter 19 (2BI) - Minimum outside temperature - 19 (2BI) – Minimum outside temperature –
This parameter defines the minimum outside temperature which marks the limit where the flow temperature
target is to be set at the temperature given by parameter 18 (2BH).

Parameter 20 (2BJ)
– Minimum heating temperature (when maximum outside temperature has been reached) –
If the outside temperature sensor registers the value set using parameter 21 (2BK), then the system targets
the minimum heating temperature set using this parameter. If the outside temperature exceeds the param­eter value, the heating demand is cancelled.

Parameter 21 (2BK) – Maximum outside temperature –
If the outside temperature exceeds the values set using this parameter, the heating demand is cancelled. At
the point where the parameter value is reached the system targets the minimum heating temperature which
has been set using parameter 20 (2BJ).

Parameter 22 (2BL) –Restart delay following temperature blocking in heating operation mode –
When the boiler is shut down on account of a temperature limit being exceeded, i.e. a set point plus offset,
the boiler restart is delayed for the period which can be set using this parameter – irrespective of whether
the hysteresis set for the next heating demand has expired or not.

Parameter 23 (2BM) – Restart delay following heating demand during heating operation –
Immediately following the end of a heating demand phase boiler restarts are delayed. That is to say, if the
boiler is shut down on account of a reference value trigger being sent from the OT bus to the firing device, a
restart (triggered by another reference value being reached) is delayed for at least the period of time which
can be set using this parameter.