Nordair Niche INDIRECT FIRED AIR HEATER (EBM) User manual

INDIRECT FIRED AIR HEATER (EBM)
INSTALLATION AND OPERATING MANUAL
INDEX Section
General Information -----------------------------------------------------------1
Technical Data ------------------------------------------------------------------ 2
Installation Details -------------------------------------------------------------- 3
DX Coil Information ------------------------------------------------------------4
Gas & Electrical Connections -----------------------------------------------5
Commissioning & Testing ----------------------------------------------------6
Controls ---------------------------------------------------------------------------7
Air Filters -------------------------------------------------------------------------8
Routine Maintenance Schedule -------------------------------------------- 9
Spare Parts -------------------------------------------------------------------- 10
User Instructions ---------------------------------------------------------------11
Wiring Diagrams--------------------------------------------------------------- 12
Fault Finding ------------------------------------------------------------------- 13
General Arrangement Drawing (loose) ---------------------- appendix 1
WARNINGS
1 This appliance must only be installed by a competent person in accordance with the requirements
of the Codes of Practice or the rules in force.
2 All external wiring MUST comply with the current IEE wiring regulations.
3 Warning this appliance must be earthed.
AmbiRad Limited, Fens Pool Avenue, Brierley Hill, West Midlands, DY5 1QA
Part No. 703022
Instruction Manual

2
1. General Information
Before installation, check that the appliance as
described on the packaging label is in
accordance with the correct type and model as
specified on the data plate and complies with the
site requirements.
Please read this document before commencing
installation.
Check that the local distribution conditions of
electricity supply, type of gas and pressure of the
appliance are compatible.
The installation must comply with the
requirements and recommendations of British
Standards BS 6230 1991. “Installation of Gas
Fired Forced Convection Air Heaters for
Commercial and Industrial Space Heating”.
The installation must also be in accordance with
relevant requirements of The Gas
safety (Installation and use Regulations) and
(Amendment regulation 1990) and the Building
and Electrical Regulation (in GB and IEE
Regulations). The requirements of the Local
Building Standards Office, the premises
Insurance undertaking and the Fire Authority
must also be observed.
Unauthorised modification of this appliance or
departure from use in the manner for which it
was intended by the manufacturer or installed in
a manner contrary to these instructions, may
constitute a hazard or jeopardise all warranties.
Deviations should only be carried out after formal
consent has been obtained from the
manufacturer.
Ensure the environment in which the air heater
will be installed will not create a hazard, i.e,
where excessive (volatile) dust, flammable or
corrosive substances and/or vapours and
combustible materials may be present. When
installing outdoor heaters care must be taken to
ensure that unauthorised access to the building
cannot be gained via the appliance or its
ductwork system.
This appliance has been tested and set
according to the data plate before leaving the
factory.
After installation the appliance must be fully
commissioned and the settings re-checked.
This appliance incorporates indirect gas fired
heat exchange modules. The modules are
purpose designed to be incorporated into air
heating appliances and the modules comply with
CE directives.
This appliance is suitable for operation within a
-10°C to +40°C temperature range.
Invalidation of guarantee
The following misuses or maltreatment of Nordair
Niche equipment will render all guarantees, as
set out on the Conditions of Sales, void.
• Failure to install, set up or put to work any part
of the equipment as specified in Nordair Niche
installation, operation and maintenance
instructions.
• Attempting to operate motors and other
electrical equipment with an electrical supply
other than that designated on the motor name
plate, or failing to connect and protect such
equipment in accordance with I.E.E
Regulations and local by-laws.
• Failure to notify Nordair Niche of equipment
damaged on receipt in writing within five days.
• Failure to run equipment within the design
specifications as notified at the time of order.
• Modifications to designed arrangement or
performances without the prior written approval
of Nordair Niche.
• Damage caused to equipment on site through
lack of adequate protection from the elements
or misuse by other trades.
• Failure to observe all normally accepted
engineering practices during installation,
commissioning and subsequent operation of
equipment.
IMPORTANT NOTE
DO NOT USE IMPACT DRIVERS ON PANELS
OR DOOR CLAMPS!
USE M5 ALLEN KEY ONLY!

3
1. General Information cont.
The fan assembly is plated mounted, which is on
a slide rail within the unit for easy removal
should it be require.
The photo below shows the fan assembly within
the unit at various stages of assembly.
EBM fan arrangement in IDF2—IDF3
retaining strap
EBM fan arrangement in IDF4.
Important:
Before the fan is started remove the fan
retaining strap shown in red above, failure to
remove the retaining strap may cause issue
and invalidate any warranties.
Before installation, check that the appliance as
described on the packaging label is in
accordance with the correct type and model as
specified on the data plate and complies with the
site requirements.
The IDFBDX-EBM models use the EBM - Papst
high performance centrifugal fan modules.
Single inlet, direct drive, 2D centrifugal impeller
with circumferential diffuser mounted on an
electronically commutated external-rotor motor
with integrated electronics. Backward curved
impeller blades, inlet nozzle made of galvanised
sheet steel with pressure relief.
Complete unit statically and dynamically
balanced in two planes according to
DIN / ISO 1940 and to balancing quality
G 6.3. EC external-rotor motor with
maintenance-free ball bearings and permanent
lubrication. A wide voltage input 1~200-277V,
50/60 Hz respectively 3~380-480V, 50/60Hz.
Unit can be operated on all standard Electricity
Board networks at identical air performance.
Optimised motor technology, soft start,
integrated current limitation, connection via
brought-out variable cable connector (motor size
084) or via easy-to-mount and robust integrated
terminal box made of aluminium with spring
loaded terminals (motor sizes 112, 150 and 200).
Extremely compact electronics, with adjustable
PID controller (motor sizes 112, 150 and 200);
meets all necessary EMC directives and all
requirements as to current reverse transfer. No
complicated installation with shielded cables
required, very low-noise commutation logic,
100% controllability. Motors with an output of 750
W or higher have the RS485/MODBUS RTU
interface. If structure-borne noise needs to be
decoupled, any such action has to be taken by
the customer.
* To be confirmed

4
2. Technical Data
Model No. Power
supply
TP&N
415v. 50
Hz
Motor
power
kW
Air
volume
m3/sec
DX
cooling
capacity
kW
No. of
stages DX heating
capacity
kW
Gas
heating
input
kW
Gas
heating
output
kW
Gas
rate
m3/hr
Weight
kg
IDF2BDX90
(CS1)*
400.3.50 1.78
1.41 28.0 2 28.0 53.3 49.0 5.63 905
IDF2BDX120
(CS1)*
400.3.50 2.83 1.89 38.0 2 44.8 53.3 49.0 5.63 905
IDF2BDX150
(CS1)*
400.3.50 2.83 2.40 44.0 2 54.0 53.3 49.0 5.63 905
IDF3BDX180
(CS2)*
400.3.50 4.7 2.77 52.0 3 60.8 78.8 72.0 8.33 1260
IDF3BDX200
(CS2)*
400.3.50 4.7 3.11 63.0 3 76.4 78.8 72.0 8.33 1260
IDF4BDX240
(CS2)*
400.3.50 6.14 3.80 66.0 3 81.0 78.8 72.0 8.33 1365
Motor
Power
@
duty
kW
1.63
2.02
2.55
2.86
3.24
4.03
Motor
Current
@
Duty
AMPS
2.47
3.07
3.93
4.33
4.94
6.37
Table 1.
Model No. Pressure
Differential
across
EBM fan Pa
K
Factor
IDF2BDX90
329 280
IDF2BDX120
591 280
IDF2BDX150
952 280
IDF3BDX180
821 348
IDF3BDX200
1035 348
IDF4BDX240
976 438
To calculate the air flow from the pressure differential
across the EBM fan
__________________
Air Flow m³/sec = K √pressure diffrential Pa
———————————-
3600
pressure diffrential Pa = Air Flow m³/sec x 3600
——————————
These calculations are to be used as a guide.
K
2

5
2. Technical Data cont.
Nomenclature IDF 2 B DX 90 S1 I/T/C – EBM
Indirect fired
Airflow 2/3/4
Heat exchanger (Benson)
Heating/cooling coil
Size 90/120/150/180/200/240
S1= without dampers, S2= with dampers
Fan Type
I= Inline, T= Trane, C=Compac
Note: If this is blank, it denotes standard configuration.

6
DAMPER/FILTER
ACCESS
COOLING COIL
AND FAN ACCESS
COOLING COIL
DRAIN OUTLET
2. Technical Data cont.
A B C
CS1 1285 1800 2552
CS2 1352 2337 3180
CS3 1352 2337 3460
Diagram 1. Overall dimensions
Diagram 2. Additional view on ‘A’
*
*
Applies if optional heat
exchanger fitted.
*
*
Shows panels
Fitted for supply air
(option ‘1’)
Table 2

7
2. Technical Data cont.
SUPPLY
AIR
RETURN
AIR
A B C D E F G H
CS1 2802 1800 695 558 440 610 46 148
CS2 3430 2337 615 840 544 887 70 148
CS3 3710 2337 895 840 544 887 70 148
Diagram 3. Base frame dimensions
A B C
CS1 780 1070 475
CS2 1235 1245 545
CS3 1235 1525 545
Diagram 4. Duct flange dimensions
Optional return/recirc air
position from store area below
(option ‘1)
Optional supply air inlet
through the roof (option ‘1’)
Optional return/recirc
air position from
store below via
ducting
Optional supply air via
ducting (option ‘2’)
Fresh air
Table 3
Table 4

8
2. Technical Data cont.
Diagram 5.
Airflow panel arrangement
Diagram 6.
Heat exchanger removal

9
R
WEATHERHOOD BOTTOM POSITION
REMOVABLE PANELS
LOCATED FOR FLOOR
SUPPLY & RETURN
SIDE DUCT SPIGOTS
UPPER SUPPLY
UPPER RETURN
WEATHERHOOD
BOTTOM POSITION
SIDE DUCT SPIGOTS
LOWER SUPPLY
UPPER RETURN
WEATHERHOOD
BOTTOM POSITION
2. Technical Data cont.
WEATHERHOOD
TOP POSITION
REMOVABLE PANELS
LOCATED FOR FLOO
R
SUPPLY & RETURN
WEATHERHOOD
TOP POSITION
SIDE DUCT SPIGOTS
LOWER SUPPLY
LOWER RETURN
WEATHERHOOD
TOP POSITION
SIDE DUCT SPIGOTS
UPPER SUPPLY
LOWER RETURN
Alternative supply/return air and weatherhood configurations
CONFIGURATION 1 CONFIGURATION 2
CONFIGURATION 3 CONFIGURATION 4
CONFIGURATION 5 CONFIGURATION 6

10
2. Technical Data cont.
IDF2BDX 120/150 S1/S2 T –EBM
2499,97
1300
102
1602
1300
1500
102
1602
FRESHAIR
RETURN AIR
OPTIONAL EXTRA
BENSON 49KW
INDIRECT GAS FIRED
HEAT EXCHANGER
44KW DX 2 STAGE
COOLING COIL
EU4 PLEATED
PANEL FILTERS
2 OFF 600x500x50
2 OFF 500x500x50
590 FILTER/
DAMPER
ACCESS
DOOR
FRESH & RETURN
AIR MOTORISED
DAMPERS
400H X 950L
888 HEAT
EXCHANGER
ACCESS
DOOR
482
CONTROLS
ACCESS
DOOR
END VIEW ON FRESH AIR
IP65 63A 3 POLE
ISOLATOR
RH ACCESS SIDE ELEVATION
PLAN VIEW
637.0
EBM PAPST 500 DIA BACKWARD
CURVED SINGLE INLET
EXHAUST PLUG FAN c/w 2.825
kW EC MOTOR
DUTY: 2.4 M3/SEC @ 450Pa ESP
875 LIFT OFF DOOR
532 LIFT OFF
DOOR
SUPPLY AIR
919 112
1076
131
413 531 464
208
480

11
2. Technical Data cont.
IDF2BDX 90/120/150 S1/S2 I/C –EBM
GAS FIRED HEATER BENSON
DM50 49kW INDIRECT GAS
FIRED MULITUBE HEAT
EXCHANGER
3128 O/ALL LENGTH
DX COOLING COIL
120 UNIT - 38kW 2 STAGE
150 UNIT - 44kW 2 STAGE
F4 PLEATED PANEL FILTERS
4-OFF 450H x 600L
ACCESS SIDE ELEVATION
PLAN VIEW
600
FILTER
ACCESS
DOOR
1212
102
530 FAN
ACCESS
DOOR
420
CONTROLS
ACCESS
DOOR
900 900 250
200
COIL
ACCESS
LIFT OFF
DOOR
400100
1001 150150
RETURN
AIR
FRESH & RETURN
AIR DAMPERS
400H x 950W
(S2 UNITS ONLY)
400100
RETURN AIR
1300
1110
1212
END VIEW ON FRESH AIR INLET
RETURN AIR
OPENING IN BASE
RETURN AIR OPENING
748
HEATER
ACCESS
DOOR
OPTIONAL SUPPLY AIR
TOP OUTLET (T.O.)
FRESHAIR
560,9
500.0
200
480
600 x 1010
DUCT SPIGOT.
40 FLG
OPTIONAL SUPPLY AIR
REAR OUTLET (R.O.)
SUPPLY AIR
END OUTLET (E.O.)
IP65 63A 3 POLE
ISOLATOR
SUPPLY AIR
END OUTLET (E.O.)

12
Handling The Equipment
Base Frame
IDF heaters are supplied with a channel base
frame, which incorporates cut-outs suitable for
lifting purposes.
Ensure that the structural elements which will be
used to support the appliance are adequate to
carry the weight of the appliance and its ancillary
components i.e. the ductwork system.
Ensure that the unit is installed on a level plane,
and that the surface onto which it is installed is
vibration free.
The heater must be lifted into position using a
suitably sized crane, with lifting bars or lifting
straps threaded through the lifting points. When
using lifting straps sling spreaders must be used
to provide clearance between the appliance and
the slings.
Each heater should be positioned onto the
existing steel frame, allowing a minimum 600mm
clearance on non-access sides and 850 mm on
the access side for removal of heat exchangers.
(See diagram 8)
When installing external weatherproof appliances
ensure that any part of the installation that may
be installed outdoors will not jeopardise the
integrity of the premises security.
The unit must be fastened securely to support
frame work.
For heaters fitting onto existing roof curbs, an air
tight seal between the base and the curb must
be made.
Sling spreaders must be used to provide
clearance between the appliance and the
slings. (See diagram 7)
Note: It is the responsibility of the installer to
ensure that safe lifting practices are followed
on site, and to note that the detail provided in
these instructions is for guidance only.
Duct Connections
Nordair Niche IDF heaters are designed to be
used in conjunction with air intake and air
distribution ducting. A positive seal must be
made between ductwork and the connection onto
the appliance. All ductwork must be supported
independently and not supported from the heater
casing.
Flexible duct connections to the appliance are
not required as the fan outlet is fitted with a
flexible connection and is isolated from the
casing via anti-vibration mounts.
Care should be taken when designing ducting
systems especially with regard to the selection of
fittings which will be installed adjacent to the
appliance, abrupt elbows fitted directly on to the
appliance can cause turbulence and create
uneven air flows across the heat exchanger,
resulting in hot spots and nuisance shut down of
the burner due to regional overheating in the
vicinity of the limit stat protection devices.
Unecessary pressure loss and noise generation
may also be caused by badly designed duct
systems.
Ducting should be manufactured from materials
suitable for the purpose also taking into account
the integrity of the building security.
Externally routed ducting should be thermally
insulated and protected with a waterproof
membrane.
3. Installation Details

13
MINIMUM
CLEARANCE
850mm
MINIMUM
CLEARANCE
600mm
MINIMUM
CLEARANCE
600mm
MINIMUM
CLEARANCE
SEE TABLE
3. Installation Details
Diagram 8.
Slinging
Diagram 9.
Clearances
Note: It is the responsibility of the
installer to ensure that safe lifting
practices are followed on site, and
to note that the detail provided in
these instructions is for guidance
only.
Coil
Removal Gas fired heat exchanger
removal
CS1*1500 1000
CS2*1700 1700
CS3*2000 1700
Fan/ heat / Coil exchanger clearances (mm)
Fan
Removal
1500
1700
2000
*See section 2 table 1. for model case sizes
Table 5
FAN REMOVAL
CLEARANCE
SEE TABLE
GAS FIRED HEAT
EXCHANGER
REMOVAL
CLEARANCE
SEE TABLE
COIL REMOVAL
CLEARANCE
SEE TABLE

14
4. DX Coil Information
DX COILS
General description
DX coils comprise a matrix of copper tubes
supported in tube end plates and associated
casing work. The tube matrix carries thin
continuous fins, regularly spaced, at right
angles to the tube matrix.
The tubes are fed via headers which
distribute the fluid between a number of
parallel circuits to give the optimum tube
velocity. The flow from the parallel circuits
rejoins in the return header. The flow to DX
evaporator coils is via distributor and
capillary tubes to ensure even distribution.
The fin array is designed to provide an
enlarged air side surface and to optimise
heat transfer for the design air conditions,
whilst minimising the resultant air side
pressure drop.
All coil blocks are tested to 22-bar air under
water, dried, vacuum tested and charged
with dry nitrogen.
F Gas certificate of engineers must only be
used for the installation, service,
maintenance or commissioning of
refrigeration air conditioning and heat pump
systems containing or designed to contain
HFC refrigerant.
Refrigerant coils
Evaporator coils are supplied with one or
more liquid refrigerant distributors connected
via capillary tubes to the coil circuitry. These
are of equal length for correct refrigerant
distribution. Care should be taken to avoid
kinking the tubes.
Refrigerant coils are generally supplied with
sealed caps, and the coil positively charged
with dry Nitrogen. The connections should be
cut or sweated off when ready for installation.
Capillary or compression fittings should be
fitted according to manufacturer’s
instructions.
Care should be taken to avoid the
introduction of foreign matter or moisture into
the system when piping up, as this may have
an adverse effect on the longevity and
performance of the system.
Maintenance
Preventative maintenance is generally required to
ensure that the coils are maintained in a clean
condition. This has three purposes:
1. Ensures that there is no marked increase in air
side pressure drop.
2. Ensures that there is no significant impairment in
air side heat transfer capability.
3. Ensures that drainage from wet coils is not
impaired over time.
Coils are virtually maintenance free, but in the
event of build up of atmospheric dust or fluff on the
fin surface, can be removed by vacuum or air blast,
taking care that all loosened debris is removed and
not carried into the distribution ductwork. In the
event of fins being pressed in, relieve with a thin
blade. Minor fin-damage has little or no effect on
coil performance.
It is normal when checking for drainage to ensure
that this occurs when the system is running, in
addition to static tests.
Cleaning
Coil drain pans extend beneath the fin block return
bends and manifolds so as to catch all moisture
condensing on the cold surfaces in the cooling
cycle. Drain pans should be inspected and cleaned
on a regular basis so as to prevent the build up of
debris and/or mould. The degree of build up is
specific to each installation and will depend largely
on the ambient contamination and class of air
filtration.
It is recommended that the drain pan be cleaned on
a 3 monthly basis, at least initially, following a
procedure broadly in line with that described below.
The drain trap to the drain pan should be
removed to allow free drainage of cleaning fluid and
a bucket or other receptacle placed below the drain
point protruding through the panel of the AHU.
Access to the coil drain pan can be gained from
either the leaving or entering air face or from the
ends of the coil after removing the necessary AHU
panel. Water or cleaning fluid can then be poured
into the drain pan or alternatively a steam spray
can be used. Take care not to flood the drain pan
during filling. Most proprietary cleaning fluids are
suitable for the galvanized steel drain pan though

15
these should be non-acidic. Foaming detergents
are best for detaching debris but detergents
should be rinsed from the pan after use to
prevent them contaminating the air stream.
After cleaning the drain trap should be refitted
and primed with water before putting back into
operation.
Recovery
There is no special recovery equipment for the
coils.
In the event of significant failure, the complete
coil should be removed for maintenance
purposes.
The most common type of failure to occur is a
tube leak. Whilst it is sometimes practical to
carry out repairs on site, removal of the
complete coil is recommended in order to
ensure subsequent integrity if repaired, or for
replacement.
In the event of coil removal being necessary,
the following procedure should be followed.
Refer to condenser manufactures instructions
on the required procedure.
F Gas certificate of engineers must only be used
for the installation, service, maintenance or
commissioning of refrigeration air conditioning
and heat pump systems containing or designed
to contain HFC refrigerant.
Disconnect connections.
Support coil as required for subsequent
dismounting, and unbolt casework flanges.
Remove coil.
Corrective maintenance
Copper coil tubes between coil block and
headers may be bent or fractured if excessive
strain is put on headers.
During installation or removal coils should be
lifted by means of the casing and NOT the
headers or connections.
Casework should be securely fixed prior to pipe
work flanges being made up.
In order for work to be carried out on the air side
faces of the coil or within the ductwork, the
system fan should be isolated.
4. DX Coil Information cont.

16
5. Gas & Electrical Connections
Gas
Connection to gas service may only be carried
out by appropriately qualified persons. The gas
installation must comply with the rules in force
using materials appropriate for gas installations.
Check that the gas category is in accordance
with the data described on the air heater data
badge.
An adequate gas supply sized to provide the
dynamic pressure for the volume required for the
air heater/s is essential to maintain the nominal
heat input. Other gas fired plant using the same
gas service must also be taken into account.
A 90˚action, positive isolating ball valve must be
fitted adjacent to the appliance, fitted in a
manner to facilitate access to the burners for
servicing purposes.
Ensure that the gas service has been tested and
purged in accordance with prescribed practice
prior to commissioning and setting the appliance
into service.
Ensure that the gas supply is filtered and it is
free of swarf or debris before connecting to the
appliance .
Electrical
The electrical installation may only be carried out
by appropriately qualified persons observing the
rules in force.
Check the electrical specification is in
accordance with the specification on the
appliance data plate. A unique appliance wiring
diagram is supplied as a separate document
attached to this one, plus an additional copy
attached to the unit.
The unit must be earthed.
Ensure that power will be supplied at all times to
the unit, even when it’s control is switched in the
“HEAT OFF” mode. This is necessary to ensure
that the air circulating fan can operate
independently of the heating control.
A separate lockable isolator for each air heater
must be provided adjacent to the appliance and
within the sight of any person working on the
appliance. The isolator must have a contact
separation of at least 3.0mm on all poles. The
isolator should be of the key operable type to
prevent vandalism and to prevent switching by
others thus placing anyone working on the
appliance at a safety risk.
Where controls are not provided by Nordair
Niche, then ancillary controls must be installed to
provide timed heat cycles, room comfort
temperature levels, frost protection, override of
air circulation etc.
Note: When working on the appliance electricity
to the appliance should not be switched OFF
before the room thermostat has been switched
OFF, the gas valve has closed and the air
circulation fan has stopped.
All cable and gas service entry points to outdoor
appliances must be sealed to prevent ingress of
water.
If it is necessary to change the rotation of blower
to match the direction indicated on blower
housing then three phase motors can be altered
by reversing two phases of the supply to the
motor.
On units fitted with centrifugal forward curved
fans, the speed setting for static pressure
imposed by the air distribution system will govern
the motor loading. The units are manufactured
for the duty specified on the data badge (Table
1).
Refer to section Drives general and adjustments
for instructions on adjusting the fan speed and
motor load factors.
After the electrical installation has been
completed the appliance should be tested prior
to the commissioning of the gas fired heat
exchanger module(s).
Note: Outdoor commissioning work on Nordair
Niche appliances should not be undertaken
during wet conditions, a second person should
always be available to provide assistance in the
event of an emergency.
Check to ensure:
• Earth continuity
• Resistance to earth
• Phase supply to correct terminals
• Current rating and circuit breaker value

17
If the Nordair Niche IDF unit is fitted with indirect
gas fired heat exchanger(s). The attached
instructions must be read and understood prior
to commencing work and must be followed for all
commissioning and service operations.
Note: Outdoor commissioning work on Nordair
Niche appliances should not be undertaken
during wet conditions, a second person should
always be available to provide assistance in the
event of an emergency.
Only persons formally qualified to work on gas
fired apparatus may carry out commissioning
and testing.
Electrical check
After completion of the installation and before
switching on the electrical supply to the
appliance, a qualified electrician must carry out a
preliminary check. The following must be
checked:
• Check to ensure that electrical cables/ wiring
do not touch the hot combustion collector box.
• Check that all wiring is connected in
accordance with the appliance circuit diagram.
• Be certain that the correct fuse value and cable
size has been provided.
• Check to ensure that the appliance is earthed
by conducting an earth continuity test.
Connect a test meter, one lead to the
appliance earth terminal and the other to the
mains incoming earth point at the electrical
isolator. A resistance reading of 1,0 ohm or
less must be indicated. If a higher reading is
obtained, check all cable connections to ensure
adequate security and cleanliness. If problem
still exists, it may be necessary to consult the
electricity supply undertaking.
• Carry out a polarity test. Connect one lead of
a suitable AC voltmeter to earth and connect
the other lead to the live supply terminal (L) at
the air heater. Switch ON the power to the air
heater and check for correct voltage. The same
result should be obtained by connecting the
test leads between live and neutral. Connect
the voltmeter test leads to N and E. A reading
of ± OV should be obtained. If these tests do
not conform with the above, there is a fault
which must be rectified before proceeding
further with the commissioning.
• Check that all sensors have been fitted in
accordance with the supplied wiring dia-
gram.
• Avoid location in draughty areas or where it
may be influenced by heat sources e.g, the
sun, process plant, etc. The thermostat or
temperature sensor should be mounted on a
vibration free surface and mounted about 1.5
metres above floor level.
Gas connection
The whole of the gas service installation
including the meter must be inspected, tested for
soundness and purged in.
Caution: Never use a flame for checking gas
soundness.
6. Commissioning & Testing

18
6.1.0 Compliance notices
The Benson Variante range of ducted warm air
heating modules detailed herewith are
manufactured by Benson Heating within a strictly
controlled environment within the parameters of
ISO9001.
These instructions are only valid if the following
country code is on the appliance GB. IE. If this
code is not present on the appliance, it is
necessary to refer to the technical instructions
which will provide the necessary information
concerning the modification of then appliance to
the conditions of use for the country.
The Benson Variante Range has been
independently tested and assessed, and has been
found to meet the Essential Requirements of the
following European Directives.
Gas Appliance Directive (90 / 396 / EEC)
Machinery Directive (2006/42/EC)
Low Voltage Directive (2006/95/EC)
Electromagnetic Compatibility Directive (2004/108/
EC)62
Product Liability Directive (85/374/EEC)
The manufacturer has taken reasonable and
practical steps to ensure that Benson Variante
Range of Heaters are safe and without risk when
properly used. These heaters should therefore only
be used in the manner and purpose for which
they were intended, and in accordance with the
recommendations detailed herewith.
The heaters have been designed, manufactured,
assembled, inspected, and tested, with safety and
quality in mind, there are certain basic precautions
which the installer and user should be aware of,
and they are strongly advised to read the
appropriate sections of the information pack
accompanying the heater, prior to installation or
use.
Benson Heating supports all new products being
supplied to their customers with a
comprehensive information pack; this clearly
defines mandatory instructions for the safe
installation, use, and maintenance, of the
appliance (s).
Where proprietary items are incorporated into
Benson Heating products, detailed information
and instructions are also provided as part of the
information pack.
It is the responsibility of the installer, owner, user,
or hirer, of such products supplied by Benson
Heating, to ensure that they are familiar with the
appropriate information manuals, supplied by the
manufacturer, and that they are suitably aware of
the purpose of the manuals and the safety
instructions. In addition, operators must be
suitably trained in the use of the appliance so as
to ensure its continued safe and efficient use.
Benson Heating has a commitment to continuous
improvement, and therefore reserves the right to
amend or change the specification of the
Variante Heater range subject to agreement from
The Notified Body.
Contained within the text of the manual, the
words 'Caution' and 'Warning' are used to
highlight certain points.
Caution is used when failure to follow or
implement the instruction(s) can lead to
premature failure or damage to the heater or its
component parts.
Warning is used when failure to heed or
implement the instruction(s) can lead to not only
component damage, but also to a hazardous
situation being created where there is a risk of
personal injury.
The Benson Variante range of heaters conform
to the following European Harmonised
Standards.
BS EN 1020 Requirements for non domestic gas
fired forced convection air heaters for space
heating incorporating a fan to assist
transportation of combustion air and / or
combustion products.
BS EN - ISO 12100-1 & 12100-2
Safety of Machinery - Basic Concepts,
General Principles for Design Part 1 & 2
BS EN 60204 - Part 1
Safety of Machinery - Electrical Equipment
for Machines Specification for General
Requirements
BS EN 60335 - Part 1
Safety of Household and Similar Electrical
Appliances General Requirements
BS EN 55014
Limits and methods of measurement of radio
disturbance characteristics of electrical
motor-operated and thermal appliances for
household and similar purposes, electrical tools
and similar electric apparatus
BS EN 50165
Electrical Equipment of non-electric heating
appliances for household and similar purposes,
6. Commissioning & Testing cont.

19
Notes:
Neither asbestos nor soft soldered joints are
used in the construction or manufacture of the
Benson range of Heaters.
The materials selected for use can withstand
the mechanical, chemical, and thermal stresses
which they will be subject to during foreseen
normal use when installed in accordance with
the manufacturers recommendations.
6.1.3 General Requirements
Caution
Before installation, check that the local
distribution conditions, nature of gas and
pressure, and the current state adjustment of
the appliance are compatible.
Warning
Unauthorised modifications to the appliance, or
departure from the manufacturers guidance on
intended use or installation contrary to the
manufacturers recommendations may
constitute a hazard.
Note:
To ignore the warning and caution notices,
and to ignore the advice from the manufacturer
on installation, commissioning, servicing, or
use, will jeopardise any applicable warranty,
moreover, such a situation could also
compromise the safe and efficient running of
the appliance itself, and thereby constitute a
hazard.
This appliance must be installed by a
competent person and in accordance with
European, National, and Local criteria,
including any relevant standards, codes of
practice the requirements of the current
building Regulations (and in particular parts J &
L), Health and safety regulations IEE
regulations and any requirements of the local
Authority, Fire Officer or insurers.
Relevant standards may include BS6230,
BS6891 and BS5588 parts 2 and 3.
Prior to installation the following points should
be considered;
a) The position of the heater for the optimum
efficient distribution and circulation of warm air.
b) The position of the heater relative to the
route of the flue.
c) The position of the heater relative to the
supply of gas.
d) The position of the heater relative to the
electrical services, wiring routes, and if
appropriate, any additional controls.
safety requirements.
The Benson Variante range of gas unit heaters
meet with the governments criteria in respect of
the Enhanced Capital Allowance Scheme.
6.1.1 Certificates of conformity
Declarations and Certificates are available upon
request from the Quality Control Department at
Benson Heating.
6.1.2 General product information
Each model size can be used as a Duct Module
(DM), are suitable for operation on natural gas
(G20) or LPG Propane (G31 - On/Off ONLY)
The Model Range is made up as follows:
Variante heaters have been approved for
alternative flue discharge arrangements These
are detailed in following pages .
Heat Exchanger
Manufactured from aluminised / stainless*
dimpled steel tube.
WARNING
(SEE FLUE INSTALLATION PAGE 20+21)
Burner
The induced draught multi burner assembly is
manufactured from aluzinc coated steel and
mounted to a common steel manifold which can
be easily withdrawn through the burner access
compartment.
Burner Control
The heaters are fitted with automatic ignition for
all models within the range.
Exhaust Fan
Combustion gases are evacuated to
atmosphere via an in built power flue venter fan
which is safety interlocked to the gas valve via
an air pressure proving device.
Model No DM50 DM72
Output kW 49.0 72.0
6. Commissioning & Testing cont.

20
e) The position of the heater relative to the
supply of fresh air.
f) The position of the heater relative to potential
stratification/circulation problems, which
generally occur at higher levels and which may
be overcome through the provision of a suitable
de-stratification unit.
g) The position of the heater relative to service
and maintenance requirements.
Caution
The heater must not be installed within an area
where the conditions are unsuitable, e.g. where
the atmosphere is highly corrosive, has a high
degree of salinity, or where high wind velocities
may affect burner operation. Suitable protection
should be provided for the appliance when it is
located in a position where it may be susceptible
to external mechanical damage from; for
example, fork lift trucks, overhead cranes etc.
6.1.4 Warranty
The heater is supplied with a 1 year parts and
labour warranty and a further year on all parts
excluding consumable’ s.
In addition to this there is also a 10 year time
related warranty on the combustion chamber.
The warranty commences from the date of
dispatch from the manufacturer, and is subject to
the terms detailed within the Benson Heating
'conditions of business'.
Note (i)
The warranty may be invalidated if -
a) The installation is not in accordance with the
general requirements of this manual.
b) The flue arrangement and air supply for the
heater are not in accordance with the
manufacturers recommendations, codes of
practice, or similar standards.
c) Air flow through the heater is not in
accordance with the manufacturers technical
specifications.
d) Internal wiring on the heater has been
tampered with or unauthorised service repairs
undertaken.
e) The main electrical supply input to the heater
has been interrupted during the heating mode.
f) The heater has been subject to and
affected by the ingress of water in any form.
g) The heater is not operated at the rating(s) laid
down in the manufacturers technical
specifications.
h) The heater has not been operated or used
within the normal scope of its intended
application.
i) The manufacturer's recommended minimum
service requirements have not been complied
with.
Note (ii)
All warranty claims must contain the following
information to enable processing to take place;
(1) Heater model.
(2) Heater serial number.
(3) Order reference/date of order, together with
full installation details (name and address).
(4) Details or symptoms of fault.
(5) Installers name and address.
Faulty parts must be returned to the Benson
Heating Spares Department, the address of
which is provided on the cover of this manual.
Any such parts will undergo inspection to verify
the claim. Replacement parts supplied prior to
this may be charged, and a credit supplied upon
subsequent validation of the warranty claim.
Consumable items are specifically not included
within the scope of the warranty.
Note (iii)
Notification is required immediately a fault is
suspected.
The manufacturer will not accept responsibility
for any additional damage that has been caused,
expense incurred, or consequential loss
resulting from any failure of the heater(s).
6.2.0 Flue Installation.
An integral flue spigot is fitted to all DM/DMV/
DMVE heaters thereby allowing the flue to
connect directly to the heater. These spigot
connections can be either side or top outlet
(specified at time of order).
The design of the flue must ensure that it can be
disconnected to allow for cleaning and servicing.
All joints should be sealed between the sections.
Warning
It is essential that the products of combustion are
flued to the outside of the building.
Each heater must have its own separate flue,
with a flue diameter of not less than is detailed
on page 34 within this manual.
The flue assembly must comply with all the
relevant regulations regarding height and
materials, and must terminate with an approved
flue terminal.
Care should be taken to ensure that the flue
terminal is not situated in a high pressure area,
6. Commissioning & Testing cont.