Powrmatic OUH 20 User guide

www.powmatic.co.uk [phone]
[email protected]
Doc Ref: M105 Issue 5.4 May 2018
Industrial & Commercial Heating Systems
OUH Suspended Oil Unit Heater
User, Installation
& Servicing Manual

page no. 2 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
Installer
Date:________________Signed: _____________________________________Installer
Commissioned
Date:________________Signed:_______________________Commissioning Engineer
Important: This certicate
must be kept with the appliance
Failure to provide a copy of the commissioning sheet invalidates the heater warranty
----------------------------------------------------
Powrmatic Ltd, Hort Bridge, Ilminster, Somerset, TA19 9PS
Tel: [phone] Fax: [phone]
Web: www.powrmatic.co.uk e-mail: [e-mail]
Certificate of Guarantee
Dear Customer
This is to certify that this heater is guaranteed for two years parts and one year labour from the date
of original commissioning. The heater must be commissioned within 4 weeks of installation.
To make a claim
In the rst instance you must contact your appliance supplier, or installer and provide:-
1. The appliance type and serial number.
2. The original commissioning documentation. As much detail as possible on the fault.
3. Your supplier, or installer, will then contact Powrmatic to make a guarantee claim on your behalf.
Conditions of Guarantee
1. The heater must have been installed by a competent recognised installer, and in
accordance with the manufacturer’s instructions, building regulations and local regulations.
2. The heater has been professionally commissioned, within 4 weeks of installation, and a copy of
the commissioning sheet returned to Powrmatic.
3. The heater has been maintained on a yearly basis by a competent servicing company.
4. The heater has been used in accordance with the manufacturer’s instructions.
5. The correct specication fuel has been used.
6. No unauthorised repairs of modications have been made. Powrmatic‘General Conditions of
Sales’have been observed.
7. Except for the obligation of Powrmatic Ltd to perform warranty repairs during the guarantee
period Powrmatic will not be liable in respect of any claim for direct or indirect consequential
losses, including loss of prots or increased cost arising from loss of use of the heater, or any
event arising there from.
Exclusions
Consumables such as gaskets, ignition electrodes, ame rectication electrodes, drive belts, fusible
links, control batteries, oil nozzles and oil line lter elements are all excluded from guarantee.

page no. 3 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
Dear Customer - thank you for choosing Powrmatic.
We appreciate you buying one of our high quality products and know that you have made the best
choice. By choosing Powrmatic, you are investing in UK manufacturing & its workforce. We pride
ourselves by manufacturing products that provide clean, comfortable and safe working environments
worldwide together with the personal & professional service and back-up you deserve. If you have
any questions or concerns regarding this product, please contact our Technical Support Team by
calling 01460 53535.
Title Section Contents Page
User Instructions 4
Pre Installation
1.1 Introduction 5
Duties 6
Dimensions 7
1.2 Technical data 8
1.3 General Requirements 10
Installation
2.1 Fitting the unit 13
2.2 General Identication of Items 15
2.3 Fitting the Flue 16
2.4 Electrical Cable Installation 17
2.5 Wiring Diagram 20
2.6 Commissioning and Testing 21
2.7 Servicing 23
Additional Documents
3.1 Fault Finding 25
3.2 List of Parts 26
3.3 Oil Conversion 28
Appendices
Information required for ecodesign (ErP) Directive 2009/125 30
Users, Installation and Servicing Instructions
CONTENTS

page no. 4 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
D) Description of Operation
Important: The heater must NOT be
controlled by switching ON and OFF the
main electrical supply to it.
1) Standard Units
The burner start up sequence will commence when the
controls e.g. Timeclock, room thermostat etc. call for heat.
The burner air fan will run and after a pre purge period the
burner will light.
Approximately 2/3 minutes after the burner lights the
heater fan will automatically start. When the external
controls are satised the burner will be turned o and
approximately 4/5 minutes later the heater fan will
automatically stop.
2) High/Low & Modulating Units
When the burners are alight, the heat output will be
controlled either to high re or low re or, in the case of
modulating units, to any point between high and low re;
depending on the requirements of the space being heated
and the external controls tted.
3) Summer / Winter Modes
Certain types of external controls will provide for two
modes of operation i.e.
Summer: The heater fan alone will run at the dictate of the
external controls to provide air movement.
Winter: The heater will operate normally.
4) Fan/Limit Stat
The fan and limit controls are mounted on the top of the air
heater.
4.1. Main Air Fan MAN / Auto
When the white button is pushed in the fan will run
continuously i.e not controlled by any external controls e.g.
Timeclock. When the white button is pulled out the fan
will start and stop automatically in conjunction with the
burner.
4.2. Limit Thermostat
This operates if high temperatures within the heater
are detected, the burners are turned o and a red
indicator light on the electrical box on top of the heater
is illuminated. The fault condition must be identied and
rectied and the thermostat manually reset.
When the unit has cooled push the reset switch on the
electrical box on top of the heater to reset the limit
thermostat interlock relay, the red indicator light will go
out and the unit is operational again.
If the heater has not been left operational
proceed as follows.
A) Checks before lighting the Air Heater
The following preliminary checks should be made before
lighting the heater(s)
a) Ensure that the ELECTRICAL supply to the heater is
switched OFF.
b) Check that all warm air delivery outlets are open.
c) Check that the thermostat is set at MAX.
d) Check that the clock control is set to an ON period.
e) Check that any other controls are calling for heat.
B) Lighting the Air Heater
1. Switch on the electrical supply at the isolator
2. If the Limit indicator light comes on press the reset
switch the electrical box on top of the heater.
3. The burner air fan will run and after a pre purge period
of approximately 30 seconds the ignition spark will be
generated and the oil valve opened. The main burner will
then start.
4. If the main burner fails to light the burner will go to
lockout and the lockout indicator / reset button on the
burner control box will be illuminated. To restart the
burner push the lockout reset button.
WARNING: If it is not possible to light the
heater after 2 or 3 attempts shut down the
heater and contact your installer/service
engineer.
C) To Shut Down the Air Heater
1) For Short Periods:
Turn the room thermostat to the OFF, or set to it’s lowest
setting.
2) For Long Periods:
Complete step 1 above.Wait approximately 4-5 minutes for
the main air fan of the heater to stop running and the turn
o the oil supplies and electric supplies to the heater.
User Instructions

page no. 5 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
Note: The limit thermostat(s) can only be reset
once the unit has cooled down.
Unless the cause of the fault condition is readily obvious,
for example a power cut whilst the heater was operating, a
service engineer should be contacted.
E) Maintenance
To maintain ecient, reliable and safe operation of the
heater it must serviced by a qualied person at least
annually and preferably at the end of the heating season.
F) IMPORTANT
Free access must be maintained to and around the heater
for servicing purposes and the air supply to the heater
must not be restricted in any way. Combustible materials
must not be stored adjacent to the heater.
All Powrmatic heaters use gas and electricity to power
them, they may also contain moving parts such as pulleys
and belts. It would be hazardous to tamper with or attempt
to service unless you are a competent person in the eld of
Oil and Electrical work.
If you have any safety questions reference the servicing
and installation of any of our heaters please do not hesitate
to contact our head oce for expert advice. Your safety is
paramount to us.
The Powrmatic OUH Range is a range of oil red forced
draught, closed ue, fanned circulation air heaters having
an output range of 20kW to 60kW .
The heaters are designed for suspension from suitable roof
points, or alternatively mounted on purpose designed
wall brackets, and are intended for heating commercial or
industrial premises.
The OUH-F has an axial type fan assembly tted at the
rear of each heater to circulate the air being heated across
the combined combustion chamber/ heat exchanger. A
centrifugal fan variation is presented in the OUH-C range
for ducted applications. The OUH-D range, in having no fan
tted, allows for ducted use where the air moving unit is
remote from the heater.
All units are red with a forced draught packaged oil
burner complete with all necessary safety controls. Each
1.1 Introduction
air heater must be connected to an individual closed ue
system only.
Fuel Types
All units are supplied as standard for use with 35sec fuel
and can be supplied for use with 28sec fuel as an option.
In accordance with guidelines from our burner supplier,
Riello, the burners tted to Powrmatic oil-red heaters are
suitable for fuels with a bio content of up to 10% only.
For fuels with a bio content of more than 10%, please
consult our Technical Department.
IMPORTANT
Service and Maintenance Engineers shall
ensure that replacement items are tted,
adjusted and set in accordance with the
data and detail set out in these instructions. If in doubt
consult Powrmatic Technical Department.

page no. 6 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
Notes:
Fuel Consumption and input figures based upon nett calorific values as follows:
- Class D light distillate fuel oil Nett CV 36.28 MJ/l
-
• Heaters have efficiency levels which meet with the minimum heater efficiency requirements of UK Part L Building Regulations
• Air handling data is assessed at room ambient conditions
• Throw figures provide the distance to the point where the terminal velocity degrades to 0.25m/s
• Noise levels are applicable to standard OUH models and are measured 5m from appliance in a typical installation situation.
• Motor kW, run and start amps apply to standard electrical supply as stated. For optional data contact sales office.
Model 20 30 45 60
Output
High Fire (max) kW 20 30 45 60
Low Fire (min) kW 16 21 34 45
Input (nett CV)
High Fire (max) kW 21.70 32.15 49.40 65.57
Low Fire (min) kW 16.40 24.20 33.70 45.17
Airflow
Volume m3/s 0.58 0.82 1.2 1.34
Throw OUH F m 8.5 16 25 34
Fan Static OUH C Pa 140 187 100 50
Electrics
Supply
Standard V/ph/Hz 230/1/50
Optional V/ph/Hz 415/3/50
OUH F
Start amp 2.26 1.14 1.70 4.20
Run amp 0.94 0.50 0.50 1.70
OUH C
Motor kW 0.55 0.55 1.1 1.5
Start amp 10.75 10.82 13.85 24.4
Run amp 4.30 4.33 5.54 9.76
Fuel Oil
Connection BSP/Rc ¼
Consumption
High Fire (max) kg/h 1.8 2.7 4.5 5.6
Low Fire (min) kg/h 1.5 2.2 3.1 4.3
Mounting Height OUH F
Min m 2.50 3.00
Max m 3.00 5.00
Overall
Dimensions
Height mm 880 1117 1117 1117
Width mm 555 780 780 780
Depth
OUH F mm 753 1106 1118 1140
OUH C mm 1038 1469 1469 1469
Installation Clearances
Top mm 1000
Side mm 500
Rear mm 400
Flue diameter mm ø 100 125
Combustion Air Spigot mm ø 150
Maximum Combustion Duct Length * m 120 100 81 21
Noise Level - OUH F models dB(A) 46 54 52 53
Nett Weight
OUH F kg 53 126 126 126
OUH C kg 91.5 142 142 142
Duties

page no. 7 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
OUH F 20 - Axial Fan
A
øD
B
CM
K
A
øD
B
CM
L
A L
B
CM
A K
FEF
B
CM
F
E
F
H
J
H
J
50
50
G
G
235 235
GE F
GE F
ØD
ØD
Model A B C D E F G K M
OUH F 20 668 555 610 100 465 101 549 85 196
OUH F 30/45/60 - Axial Fan
A
øD
B
CM
K
A
øD
B
CM
L
A L
B
CM
A K
FEF
B
CM
FEF
H
J
H
J
50
50
G
G
235 235
GEF
GE F
ØD
ØD
Model A B C D E F G K M
OUH F 30 975 780 847 125 490 276 490 171 196
OUH F 45 975 780 847 125 490 276 490 143 202
OUH F 60 975 780 847 125 490 276 490 173 202
OUH C 20 - Centrifugal Fan
A
øD
B
CM
K
A
øD
B
CM
L
AL
B
CM
A K
F
E
F
B
CM
FEF
H
J
H
J
50
50
G
G
235 235
GE F
GE F
ØD
ØD
Model A B C D E F G K M
OUH C 20 668 555 610 100 465 101 549 85 196
Dimensions

page no. 8 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
OUH C 30/45/60 - Centrifugal Fan
A
øD
B
CM
K
A
øD
B
CM
L
AL
B
CM
A K
F
E
F
B
CM
F
E
F
H
J
H
J
50
50
G
G
235 235
GE F
GEF
ØD
ØD
Model A B C D E F G K M
OUH C 30 975 780 847 125 490 276 490 131 196
OUH C 45 975 780 847 125 490 276 490 143 202
OUH C 60 975 780 847 125 490 276 490 165 202
MODEL Burner
Type
Nozzle Pump
Pressure
Head
Setting
Combustion
Air
Nominal
CO NOx Nett Flue Temp
Danfoss bar p.s.i. no. no. (mm) %ppm °C
OUH20 RG1 RKD 0.50Gal 60° S High Fire 12.41 180 0.3 1.0 12.56 84.3 193
Low re 8.27 120 0.3 0.2 12.46 74.6 135
OUH30 RG1 RKD 0.75Gal 60° S High Fire 12.07 175 1.3 2.2 12.55 63.2 171
Low re 8.96 130 1.3 0.5 12.58 65.4 150
OUH45 RG2D 1.10Gal 60° S High Fire 15.17 220 3.0 1.0 12.45 72.7 249
Low re 8.27 120 3.0 0.25 12.52 65.3 196
OUH60 RG2D 1.25Gal 45° S High Fire 15.17 220 4.0 412.73 59.8 300
Low re 8.27 120 4.0 0.7 12.16 52.8 232
Riello Burner Settings - 35sec Oil - Diesel - Net CV (H = 42.69MJ/kg)
Notes: CO values and Nett ue gas temperatures are given for guidance and measured values will depend on site conditions.
1.2 Technical Data

page no. 9 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
/F Models /CCF Models
MODEL
Start Amps
(A) Run Amps (A) Fuse Rating (A) Motor kW Start Amps (A) Run Amps (A) Fuse Rating (A)
OUH20 2.26 0.94 20.55 10.75 4.3 10
OUH30 1.14 0.5 20.55 10.82 4.33 10
OUH45 1.7 0.5 21.1 13.85 5.54 13
OUH60 4.2 1.7 31.5 24.4 9.76 13
Electrical Loadings - 1Pha
MODEL Air Volume External
Static
Pressure Throw Maximum
Duct
Resistance
Fan
Motor Noise Level Weight
m³/s m³/h Pa mPa kW dB(A) kg
OUH20 F0.70 2520 n/a 8.5 n/a 0.26 46 53.0
CCF 1.0 3600 275 n/a 140 0.42 TBA 91.5
OUH30 F0.82 2952 n/a 16 n/a 0.13 54 126
CCF 0.82 2952 305 n/a 187 1.1 TBA 142
OUH45 F1.19 4284 n/a 25 n/a 0.27 52 126
CCF 1.19 4284 275 n/a 100 1.1 TBA 142
OUH60 F1.94 6984 n/a 34 n/a 0.27 53 126
CCF 1.88 6768 384 n/a 50 1.1 TBA 142
Heater Specications
MODEL Burner
Type
Nozzle Pump
Pressure
Head
Setting
Combustion
Air
Nominal
CO NOx Nett Flue Temp
Danfoss bar p.s.i. no. no. (mm) %ppm °C
OUH20 RG1 RKD 0.55Gal 45° S High Fire 10.0 144 0.3 1.0 12.56 84.3 193
Low re 7.0 100 0.3 0.2 12.46 74.6 135
OUH30 RG1 RKD 0.85Gal 45° S High Fire 10.0 144 1.3 2.2 12.55 63.2 171
Low re 7.0 100 1.3 0.5 12.58 65.4 150
OUH45 RG2D 1.25Gal 45° S High Fire 10.0 144 3.0 1.0 12.45 72.7 249
Low re 7.0 100 3.0 0.25 12.52 65.3 196
OUH60 RG2D 1.50Gal 45° S High Fire 10.0 144 4.0 412.73 59.8 300
Low re 7.0 100 4.0 0.7 12.16 52.8 232
Notes: CO values and Nett ue gas temperatures are given for guidance and measured values will depend on site conditions.
Riello Burner Settings - 28sec Oil - Kerosene - Net CV (H = 47.00MJ/kg)

page no. 10 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
1.3.1. Related Documents
All OUH heaters comply with the following European
Directives:
Energy Related Product Directive: 2009/125/EC*
Electromagnetic Compatibility Directive: 2004/108/EC
Low Voltage Directive: 2006/95/EC
Machinery Directive: 2006/42/EC
Air heater(s) must be installed in accordance with BS5410
Part 2, BS799 Part3 & part 5 and BS5440 plus any relevant
requirements of local and national building codes. * where
appropriate
1.3.2 Location
The location chosen for the air heater must permit the
provision of a satisfactory ue system and an adequate air
supply. The location must also facilitate ease of servicing
and satisfactory air circulation around the heater.
The air heater must be installed strictly in accordance with
any re regulations or insurance company's requirements
appertaining to the area in which the heater is located,
particularly where special risks are involved such as areas
where petrol vehicles are housed, cellulose spraying areas,
and wood working departments etc.
The air heater must be installed either:
1) OUH 20 models;-
(a) Suspended by chains or straps of adequate strength to
safely carry the weight of the unit and ancillary equipment
2) OUH 30/45/60 models:-
(a) Suspended from ’drop rods’ via purpose designed M10
suspension xing points from the heater. Threaded drop
rods must have lock nuts tted that are tightened down
onto the 10mm xings in the heater.
(3) All OUH models:-
(a) in all cases, it is important that all supporting structures
have been assessed with regards to the relevant weight
loading.
(b) On specically designed cantilever brackets from a non-
combustible wall or
(c) On a level non-combustible surface which is capable of
adequately supporting the weight of the air heater and any
ancillary equipment.
The heater must not be installed in conditions for
which it is not specically designed e.g. highly corrosive
atmospheres, vitiated atmospheres, or where adverse wind
conditions may be experienced. Where the location of
the heater is such that it might suer external mechanical
damage e.g. from overhead cranes, fork lift trucks etc.
it must be suitably protected. Any ducting should be
kept as short and direct as possible having regard to the
distribution of the heated air and the max duct resistance
shown in section 1.3.10.
Any combustible material adjacent to the heater and
ue systems must be so placed as to ensure that its
temperature does not exceed 65°C (150°F).
1.3.3 Electrical Supply
Wiring external to the air heater must be installed in
accordance with the I.E.E. Regulations for Electrical
Installations and any local regulations which apply.
All standard heaters are supplied by 230V - 1ph, 50Hz. The
method of connection to the main electricity supply must:-
- facilitate the complete electrical isolation of the unit(s)
- be in a readily accessible position adjacent to the unit(s)
- serve only the unit(s)
- have a contact separation of at least 3mm in all poles. See
the accompanying wiring diagram for the heater electrical
connections
OUH units can also be supplied for 400V 3N, 50Hz.
1.3.4 Oil Supply
Construction and installation of service tanks and ttings
should be in accordance with:
(a) BS 5410 Part 2 Section 6
(b) BS 799 Part 5
(c) BS 1563
In addition the service tank installation must comply with
local regulations and by-laws and with the requirements of
insurance companies
Refer to the detail provided in the burner handbook
regarding oil pipe sizing. These must be generally in
accordance with BS799 Part 3 and BS5410 Part 2.
Particular attention is drawn to the following:
a) Pipe jointing compounds must be capable of
withstanding the solvent action of the fuel oil under
all operating temperatures and pressures. Jointing
compounds containing oil shall not be used. Hemp and
other brous materials shall not be used as packing for
screwed joints.
b) Soft solder copper tube ttings and galvanised pipes
and ttings must not be used.
c) Oil lines must be completely air-tight.
d) The pump suction must not exceed a maximum of 0.4
bar (30cm Hg). Beyond this limit gas may be released from
the oil.
1.3 General Requirements

page no. 11 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
WARNING: The burners are supplied
adjusted for a single pipe system. If the
burner is to be used on a twin pipe system
the Internal bypass plug of the burner oil
pump must be tted. Refer to the burner instruction
booklet.
Ideally the return pipe should terminate within the oil tank
at the same level as the suction line, both being below the
minimum oil level.
1.3.7 Fire Valve
It is recommended that the re valves should be installed
as follows:
1. Main storage to service tank supply (if applicable)
2. Main storage to burner supply
3. Service tank to burner supply (if applicable)
Fire valves should be installed generally in accordance with
the requirements of BS799: Part 5. The re valve should be
situated in an easily accessible position as near the tank as
possible and where practicable within the boundary of the
tank chamber or catchpit retaining wall.
1.3.8 Flue System
Only ue systems supplied through Powrmatic Ltd may be
used with OUH units. Several congurations of ue and
combustion air ducts are available.
The ue must terminate in a freely exposed position and
be sited to prevent the products of combustion entering
any opening in a building in such concentration as to be
prejudicial to health or a nuisance.
1.3.9 Combustion & Ventilation Air Supply
Type B ued installations.
Where OUH heaters are installed within the heated
space (ie not in a plant room or an enclosure) and
having a building design air change rate of greater than
0.5/h, additional provision for ventilation is not required.
If the building design air change rate is less than 0.5/h,
additional provision for natural or mechanical ventilation
is required. These being:
Natural Ventilation:
Grilles having a free area of at least 2cm² per kW of rated
heat input shall be provided at low level i.e. below the level
of the heater ue connection.
Mechanical Ventilation:
Must ensure that the space air change rate is at least 0.5/h,
must be of the ‘input’ type and interlocked to ensure the
heaters cannot work if the input system is not working.
Type B ued installations.
Where OUH heaters are installed in a plant room
or an enclosure (ie not within the heated space)
having combustion air drawn directly from the room
and connected to a ue that evacuates the products of
combustion directly from the room additional provision for
natural or mechanical ventilation is required. These being:
Natural Ventilation:
There must be permanent air vents communicating
directly with the outside air, at high level and at low level.
Plant Rooms
Low level (inlet) 4cm²/kw of total rated net heat input
High level (outlet) 2cm²/kw of total rated net heat input
Enclosures
Low level (inlet) 10cm²/kw of total rated net heat input
High level (outlet) 5cm²/kw of total rated net heat input
Mechanical Ventilation:
The minimum ow rate of ventilation shall be 4.14m³/h per
kilowatt of total rated heat input.
Type B23 Installation (these refer to section 1.4.1 of these instructions)
Air vents shall be permanently open.
Figures in column 1 are for heaters installed in the space they are heating.
Figures in column 2 are for heaters installed in a plant room, ventilation to outside air.
Figures in column 3 are for heaters installed in a enclosures, ventilation to outside air.
In all cases gures are per heater installed.
For multi heaters installations the appropriate values for each heater must be added together.
OUH Input
kW
In the heated
space In a plant room, ventilation to outside In an enclosure, ventilation to outside
Low level grille.
Free area cm²
Low level grille.
Free area cm²
High level grille.
Free area cm²
Low level grille.
Free area cm²
High level grille.
Free area cm²
20 21.70 43.84 87.68 43.84 219.2 109.60
30 32.15 64.30 128.6 64.30 321.5 160.75
45 49.40 98.80 197.6 98.80 494.0 247.0 0
60 65.57 131.14 262.28 131.14 655.7 327.85

page no. 12 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
1.3.10 Air Distribution System
Where single OUH units are required to cover a large oor
area, and in buildings with high roof or ceiling heights
Calecon thermal economiser units should be tted to
ensure even heat distribution and minimise stratication.
Care should be taken to avoid impeding the air throw with
racking, partitions, plant or machinery etc. Various outlet
congurations are available as optional extras to modify
the air throw pattern to suit particular site conditions.
For ducted units all delivery and return air ducts, including
air lters, jointing and any insulation or lining must be
constructed entirely of materials which will not contribute
to a re, are of adequate strength and dimensionally stable
for the maximum internal and external temperatures to
which they are to be exposed during commissioning and
normal operation.
Where inter-joist spaces are used as duct routes they
should be suitably lined with a re-resisting material.
A full and unobstructed return air path to the air heater(s)
must be provided.
If the air heater(s) is installed in a plant room the return air
intake(s) and the warm air outlet(s) from the heater(s) must
be fully ducted, into and out of the plant room to avoid
interference with the operation of the heater.
The openings in the structure of the plant room through
which the ducting passes must be re stopped.
Care must be taken to ensure that return-air intakes are
kept clear of sources of smells and fumes, and where there
is any possibility of pollution of the air by dust, shavings
etc., precautions must be taken to prevent contamination.
If necessary suitable barrier rails should be provided to
prevent any combustible material being placed within
900mm of the outlets.
Model Air Volume m³/h Maximum Duct Resistance
OUH20 2088 140
OUH30 2952 187
OUH45 4320 100
OUH60 6840 50
Ducting Requirements
t
OUH C Air Heater

page no. 13 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
B
C
D
Distance from outside of heater to closest obstacle Distance
ARHS Clearance (when viewed at front of heater) mm 500
BLHS Clearance (when viewed at front of heater) mm 500
CTop of heater mm 1000
DRear of heater (dependent on ue system) mm 400
ERecommended mounting heights (oor level to underside of unit) OUH20/30F mm 2500-3000
OUH45/60F mm 3000-5000
For multi air heater installations the following minimum distances between units must be observed
Between units, side to side mm 3000
Between units, back to back mm 3000
E
Front View
R/H Side Views
D
B
2.1 Fitting the Unit

page no. 14 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
2.1.1 Fitting space requirement
The air heater will be delivered to site pallet mounted and
protected by plastic sheeting.
The minimum clearances detailed in section 2.1 must be
observed for installation and servicing.
Any combustible material adjacent to the air heater and
the ue system must be so placed or shielded as to ensure
that its temperature does not exceed 65 °C.
In order to achieve the desired performance levels it is
recommended that the installation height (oor level to
base of unit) for OUH20 and OUH30 is between 2.5m and
3.0m, and OUH45 and OUH60 is between 3.0m and 5.0m.
If the heater is to be base mounted it may be stood
directly on the platform, provided it is of a suitable non-
combustible material and does not extend past the front
edge of the heater.
Any combustible material adjacent to the air heater and
the ue system must be so placed or shielded as to ensure
that its temperature does not exceed 65 °C.
When OUH modular components are used in conjunction
with the heater each component must be individually
supported.
2.1.2 Suspending the heater
The air heater may be installed either:
a) Suspended by steel chains, rods or straps, dependant on
OUH model.
b) on specically designed cantilever brackets from a non
combustible wall.
c) on a level noncombustible surface. The surface must not
extend past the front edge of OUH heaters.
The method of installation must be capable of adequately
supporting the weight of the unit (See section 1.2, page 9)
and any ancillary equipment. Before installing the heater
the existing structure must be inspected to ensure it is
suitable. All supports should be protected against the
eects of rust or corrosion.
If noise levels are of particular importance, the heater
should be isolated from the structure of the building by
installing it on suitable anti-vibration mountings.
In all such cases, and in addition, when the heater is
suspended it is essential that all oil, duct, electrical and
ue connections to the heater are made with exible
connections to maintain continuity of connection. In the
case of the ue connection single wall stainless steel ue is
deemed to ex suciently to meet the requirements.
Raise the heater up to the point of installation using
suitable and safe means and connect to the means of
suspension.
2.1.3 Air Distribution System
2.1.3.1 General
OUH/C and OUH/D models are designed for use with duct
work to more precisely dene the point of air delivery,
and /or provide ducted return air or ducted fresh air inlet.
All ducting must be independently supported of the air
heater.
Joints and seams of supply ducts and ttings must be
securely fastened and made airtight. If required the
ductwork should be insulated to reduce heat loss.
2.1.3.2 Noise Reduction
Ducting should be connected to the heater spigots
via an airtight exible coupling of non-combustible
material. Before tting the coupling it must be ensured
that a minimum clearance of approximately 15mm will
be maintained between the ends of the ducting and the
heater spigots.
Sound attenuators may be tted in inlet and outlet ducts
to reduce airborne fan noise. Materials used in outlet
sound attenuators must be capable of withstanding 100°C
air temperature without any deterioration.
2.1.4 Room Thermostat Siting
The room thermostat should be tted at a point which will
be generally representative of the heated area as far as
temperature is concerned. Draughty areas, areas subjected
to direct heat e.g. from the sun, and areas where the air
movement is relatively stagnant e.g. in recesses, are all
positions to be avoided.
The thermostat should be mounted about 1.5m from the
oor.
Any room thermostat, frost thermostat, time clock etc.
must be suitable for switching 230V, 5A and must be of the
'snap action' type to minimise contact bounce.
For electrical connections of external controls see section
2.5 or the accompanying wiring diagram.

page no. 15 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
2.1.5 Oil Connection
The oil pipework length and diameter should be in
accordance with the information given in the burner
instruction booklet.
The pump suction should not exceed 0.4 bar.
The oil line must terminate not more than 450mm from
the burner with the nal connection by the exible hoses
supplied with the burner.
Because the burner is at high level it is recommended
that a non-return valve is tted adjacent to the burner to
prevent oil draining back when the burner is not operating.
2.1.6 Electrical Connections
All units are fully prewired and only require nal
connection of the incoming mains supply and completion
of the control circuit (230V) via a room thermostat, time
clock etc.
All units must be earthed. The electrical supply must
be run to a point adjacent to the heater and be suitably
terminated to provide an isolation point that will prevent
remote activation of the unit during servicing. See section
1.2 to ascertain the electrical loading of the unit(s) so
that cables of adequate cross-sectional area are used for
the electrical installation. The length of the conductors
between the cord anchorage and the terminals must be
such that the current carrying conductors become taut
before the earth conductor if the cable or cord slips out
of the cord anchorage. All external controls must be of an
approved type.
OUH/D models supplied less fan must be electrically
interlocked to the air movement system so that this is
started in the same manner as the air heater fan would be
viz. A connection from heater terminal 8 must be made
to one side of the fan motor contactor coil, the other side
of the coil being connected to Neutral. The fan motor
electrical supply must be direct and not taken from the
internal wiring of the OUH heater.
2.2 General Identication of Items
RIELLO BURNER
FLUE OUTLET
ELECTRICAL BOX
AXIAL FAN
FAN / LIMIT THERMOSTAT
HIGH LIMIT RESET

page no. 16 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
2.3.1. General Requirements
The minimum distance between surfaces of the ue pipe
and any surfaces made from combustible materials is
300mm. If it is necessary for the ue pipe to pass through a
structure made from combustible materials a metal sleeve
must be used so that the minimum clearance of 300mm is
maintained.
2.3.2 Connection of Air Heater(s) to Flue System
All models are supplied with a rear ue outlet.
The ue system connects directly into the ue socket on
the top (OUH20) or rear (OUH30 - 60) of the heater. The
socket is sized to accept standard sheet metal ue that is
secured in place using suitable fasteners.
The ue system must be fabricated with sockets facing
upwards and sound joints must be achieved by either:
(a) a close tolerance mechanical t between sections, or
(b) the use of a suitable caulking string and cold caulking
compound.
In all cases the ue outlet socket must be connected via an
approved ue system to outside air.
The minimum ue length (end of ue terminal to top of
heater) shall not be less than 2.0m.
All ue ducts must be supported independently of the air
heater.
2.3.3. Installation of Flue System
A closed chimney system that conforms to the
requirements of EN1856-1 and has a designation
appropriate to the application must be connected to the
outlet of this tee. The cross sectional area of the chimney
serving the appliance must be not less than the area of the
ue outlet of the air heater.
The chimney must have a minimum height, from the
heater to the ue terminal, of 2m.
Horizontal runs of ue must be minimised but where they
are unavoidable the ratio of vertical to horizontal ue
should be not less than 3:1.
If necessary a single oset using two 45° bends can be
included to avoid obstructions. The minimum equivalent
resistance of the ue system should not be less than 0.0mb,
the maximum not greater than 0.5mb.
In order to minimise condensation the use of twin wall
chimney is recommended. With high eciency heaters
some condensation in the chimney, particularly at the
terminal, is unavoidable and in addition there can also be
rain water ingress.
Facilities should be made for disconnecting the chimney
pipe(s) from the air heater(s) for inspection and servicing
purposes.
The chimney outlet must be tted with a terminal and
where the heater chimney is less than 200mm (8") in
diameter an approved terminal must be used.
The chimney must be supported independently of the air
heater.
The chimney must terminate in a freely exposed position
and must be situated so as to prevent the products of
combustion entering any opening in a building in such
concentration as to be prejudicial to health or a nuisance.
The chimney terminal must be installed not less than:
- 300mm below an opening e.g. window, air brick etc.
- 200mm below eaves or gutter.
- 300mm from an internal or external corner.
- 1200mm from a surface facing the terminal.
- 1500mm vertically from another terminal on the same
wall.
- 300mm horizontally from another terminal on the same
wall.
- 2000mm from ground level.
2.3.4. Condense Drainage
The design of the ue system should minimise the
formation of condensation and long external runs
should be completed in twin wall insulated ue. Where
condensate and/or rain water ingress is envisaged to be a
problem a ue drain length or condensate drain tee that
drains into a gulley must be tted.
2.3 Fitting the Flue

page no. 17 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
2.4.1 Electrical Connections
Warning: THIS APPLIANCE MUST BE
EARTHED.
Wiring external to the air heater must be installed in
accordance with the I.E.E. Regulations for Electrical
Installations and any local regulations which apply. Wiring
should be completed in exible conduit.
Heaters are for use with 230V, 1N, 50Hz supplies.
The method of connection to the main electricity supply
must:-
- facilitate the complete electrical isolation of the heater(s)
that will prevent remote activation of the heater during
servicing.
- be in a readily accessible position adjacent to the
heater(s).
- serve only the heater(s).
- have a contact separation of at least 3mm in all poles.
See the wiring diagram for the heater electrical
connections section 2.5
All units are fully prewired and only require nal
connections for the incoming mains supply and
completion of the control circuit (230V).
Warning: Any controller or thermostat
must receive its supply from the heater
terminals 10, 11 & 12 to ensure safe
isolation during maintenance.
Reference must be made to Section 1.2 to ascertain the
electrical loading of the unit(s) being installed so that
cables of adequate cross-sectional area are used for
the electrical installation. The length of the conductors
between the cord anchorage and the terminals must be
such that the current carrying conductors become taut
before the earth conductor if the cable or cord slips out
of the cord anchorage. All external controls must be of an
approved type.
2.4.2 Initial Wiring Instalation
Key
A = 2 core and earth
B = Powrtrol = 4 core and earth
Powrtrol RR= 4 core and earth
MC200 On/O = 4 core and earth
D= Screened 2 core (MC200 models only)*
* (screen must be grounded only at the MC200, See
instructions supplied with controller for wiring sizing,
Max. 100m)
2.4 Electrical Cable Installation

page no. 18 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
NOTE:
To achieve maximum system eciency it is
recommended that OUH units are controlled
by an MC200 Fuel Saver unit. Simple room
thermostat and thermostat/time clock control systems will
not provide optimum system eciency and fuel savings.
Wiring drawings and instructions are supplied with the
respective controller.
2.4.4 External Fuses
2.4.3 External Wiring
The wiring terminals are located under the lid of the electrical box on top of the unit.
The mains supply ( single or three phase) connections are via a 3 way terminal block.
F - Free Blowing Unit C - Centrifugal Unit
Model Running
Current (A) Fuse/MCB Rating (A) Running Current (A)
Fuse/MCB Rating (A)
(motor rated Protection Device)
OUH20 0.94 34.3 10
OUH30 0.50 34.33 10
OUH45 0.50 35.54 13
OUH60 1.7 39.76 13
230V Heat Low Demand
230V Main Fan Only
230V Heat High Circuit
230V Lockout Indication
230V LNE to Controller
terminal 1
terminal 3
terminal 4 & 5
terminal 6
terminal 11, 12 & 13
L N
E
Output 230V Input 230V
Fan Only Signal 230V Heat On Signal 230V
Live Output Neutral Earth
t1 t3 t4 t5 t6 t10 t11 t
230V Supply
for Controller
High
Fire
Circuit
Lockout Signal 230V

page no. 19 of 32
OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
2.4.5.1. Interconnecting Wiring:
OUH Installer Connections
2.4.5.2. Interconnecting Wiring:
OUH to Powrmatic MC200
LN
12345678910 11 12
HEAT LO: 230V
FAN ONLY: 230V
HEAT HI
LOCKOUT: 230V
LIVE
NEUTRAL
EARTH
230V SUPPLY TO
CONTROLLER
T6A
FUSE / MCB
LIVE
NEUTRAL
EARTH
T1
T2
Remote lockout signal
(230V 0.5A max.)
2nd stage thermostat (remove link)
T1
T2
1st stage thermostat
=
=
=
OUH Electrical Control Panel
FD
FD Fan only demand (Summer cooling option)=
1st stage thermostat
2nd stage thermostat
(remove stat)
Remote lockout thermostat
(230V 0.5A max)
Fan only demand
(Summer cooling option)
LN
12345678910 11 12
HEAT LO: 230V
FAN ONLY: 230V
HEAT HI
LOCKOUT: 230V
LIVE
NEUTRAL
EARTH
230V SUPPLY TO
CONTROLLER
T6A
FUSE / MCB
LIVE
NEUTRAL
EARTH
T1
T2
Remote lockout signal
(230V 0.5A max.)
2nd stage thermostat (remove link)
T1
T2
1st stage thermostat=
=
=
OUH Electrical Control Panel
FD
FD Fan only demand (Summer cooling option)=
LN
12345678910 11 12
HEAT LO: 230V
FAN ONLY: 230V
HEAT HI
LOCKOUT: 230V
LIVE
NEUTRAL
EARTH
230V SUPPLY TO
CONTROLLER
T6A
FUSE / MCB
LIVE
NEUTRAL
EARTH
T1
T2
Remote lockout signal
(230V 0.5A max.)
2nd stage thermostat (remove link)
T1
T2
1st stage thermostat=
=
=
OUH Electrical Control Panel
FD
FD Fan only demand (Summer cooling option)
=
LN
12345678910 11 12
HEAT LO: 230V
FAN ONLY: 230V
HEAT HI
LOCKOUT: 230V
LIVE
NEUTRAL
EARTH
230V SUPPLY TO
CONTROLLER
T6A
FUSE / MCB
LIVE
NEUTRAL
EARTH
T1
T2
Remote lockout signal
(230V 0.5A max.)
2nd stage thermostat (remove link)
T1
T2
1st stage thermostat=
=
=
OUH Electrical Control Panel
FD
FD Fan only demand (Summer cooling option)=
Notes on both diagrams:
All signals are 230V AC 50Hz
Any controller or thermostat must receive its
supply from the heater terminals 10, 11 & 12
to ensure safe isolation during maintenance.
If a second stage thermostat is tted for
High/Low operation, remove the link that is
tted between terminals 4 & 5.
Warning: External controls
MUST be powered via heater
terminal 10, 11 and Earth
Warning: External controls
MUST be powered via heater
terminal 10, 11 and Earth
1 2 3 4 5 6 7 8 9 10 11 12
HEATL O:230V FANONLY: 230V
LIV E NEUTRAL
HEATHI
LOCKOUT:230V
EARTH
230V SUPPLY TO
CONTROLLER
LIVE
EARTH
NEUTRAL
T1
T2
OUH Electrical Control Panel
FD
LN
T6A
13 14
1 2 3 4 5 6 7 8 9 10 11 12
HEATL O:230V
FANONLY: 230V
LIV E NEUTRAL
HEATHI
LOCKOUT:230V
EARTH
230V SUPPLY TO
CONTROLLER
LIVE
EARTH
NEUTRAL
OUH Electrical Control Panel
L N
T6A
13 14
MC200 fuelsaver
SEN1
COM
IN2
0-10v+
0-10v-
Reset
Lockout
In
Heat Hi
Out
Heat Hi
In
Heat Lo
HeatL o
Out
FanIn
N
FanOut
E
L
LOut

page no. 20 of 32 OUH Range Users, Installation & Servicing Instructions Doc Ref M105 issue 5.4 May 2018.
2.5 Wiring Diagram
LN
T6A
Wiring Legend
Installer
Electrical Data
Connections made by Control
board Assembler
Connections made by Final
Assembler
Connections made by
6 7
Mains Input: 230v 50Hz 1ph Supply. For total
Power refer to user instructions.
8 9 10
EARTH
NEUTRAL
LIVE
MAINS SUPPLY
230v 1ph 50Hz
11 12
Controls
Main Fan Only 230V Input
Connections
Heat Demand 230V Input
t1t2
LNs3
b4
t1 t2
LNs3
b4
123 4 5
t6t7
t8
b5
t6t7
t8
b5
2nd Stage Thermostat
(High Fire)
Remove link - T4 & T5
Burner Lockout
Indicator 230V Output
L
N
E
230V Supply for
Controls
HIGH LIMIT
/RESET
INDICATOR
MAIN
FAN
RIELLO
BURNER
LIMIT
FAN
ºc
COM
NO
NC
13 14
6
5
4
2
3
1
10
9
11
87
NO
COM
NC
N
LTRP
COM
NO
NC
16 17
15
STAT
FAN/LIMIT
PCB
remove
Do not
LIMIT INTERLOCK
RELAY
RELAY
Cut mode BA
link 'B'
T1
T2
Tx
= Thermostat
= 230v Indicator
link
External