Powrmatic NVx10, NVx25, NVx15, NVx20, NVx30 User, Installation And Servicing Instructions

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Page 1

Users, Installation and Servicing

Instructions

WARNING: THIS APPLIANCE MUST BE EARTHED

IMPORTANT: Reset from Lockout is by a switched Neutral

NVx Range Users, Installation & Servicing Instructions Issue 1.9 March 2012

The NVx Range

(Brahma Control)

Page 2

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.

The heat exchanger, where fitted, is guaranteed (parts only) for a further eight years, chargeable on a sliding scale basis, price relative to age.

To make a claim

In the first instance you must contact your appliance supplier, or installer and provide:-

1. The appliance type and serial number.

2. The original commissioning documentation.

3. As much detail as possible on the fault. 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 manufacturers 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 manufacturers instructions.

5. The correct specification fuel has been used

6. No unauthorised repairs or modifications have been made.

7. Powrmatic ‘General Conditions of Sale’ have been observed.

8. 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 profits or increased costs arising from loss of use of the heater, or any event arising there from.

Exclusions

1. Gaskets and fan belts are not included in the guarantee

Important: This certificate must

be kept with the appliance

Certificate of Guarantee

Powrmatic Ltd, Hort Bridge, Ilminster, Somerset, TA19 9PS

tel: 01460 53535 fax: 01460 52341

web: www.powrmatic.co.uk e-mail: [email protected]

Installed

Date: ___________ Signed______________________________________ Installer

Commissioned

Date: ___________ Signed________________________ Commissioning Engineer

Failure to provide a copy of the Commissioning Sheet invalidates the heater warranty

Page 3

1. 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.

2. Lighting the Air Heater

NOTE: On initial lighting of the heater(s), it may take some time to purge the internal pipe work of air. If it is not possible to light the heater after several attempts contact the local service company.

1. Switch on the electrical supply at the isolator and the start up sequence will commence. Note: Check that the red overheat indicator on the front of the unit is not alight. If it is refer to Section 4.4 After a short delay the burners will light and the green ‘ON’ indicator on the front of the heater will be illuminated.

2. If the burners fail to light the control box will automatically restart the ignition sequence. If after 5 attempts at ignition the burners have still failed to light the control box will go to lockout and the lockout light on the low level remote reset (or MC200 or Powrtrol RR if fitted) will be illuminated. To restart the ignition sequence depress the reset button on the low level reset for about 1-2 seconds. If the heater will not light after two or three attempts shut down the heater and contact a service engineer.

3. To Shut Down the Air Heater

3.1 For Short Periods: Turn the room thermostat to the OFF or lowest setting.

3.2 For Long Periods: Complete step 3.1 above. Wait for 5 minutes and then turn OFF the electrical supply at the isolator.

4. Description of Operation

Important: All heaters must be controlled by the fitted external controls and not by use of the main switch in the electrical supply to the heater.

4.1 Standard Units

The ignition sequence will commence each time that the external controls e.g. Time clock, room thermostat etc. call for heat. The internal exhaust fan will run and when sufficient combustion airflow is proved by the air pressure switch the ignition spark will be generated, the main gas valves opened and the burners lit. The green ‘ON’ indicator will be illuminated. The heater fan will automatically start approximately 2 minutes after the burners light. When the external controls are satisfied the burners will be turned off and approximately 2 - 3 minutes later the heater fan will be automatically stopped.

4.2 High / Lo & Modulating Units

When the burners are alight the heat output will be controlled either to high fire or low fire or, in the case of modulating units, to any point between high and low fire; depending on the

requirements of the space being heated and the external controls fitted.

4.3 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.

4.4 Overheat Thermostat

This operates if high temperatures within the heater are detected, the burners are turned off and a red indicator light on the front panel is illuminated. NVx10 - 75 units have the thermostat located inside the controls section. NVx90 - 140 units have an additional thermostat on the side of the unit at the opposite end to the controls (either thermostat can go to limit and shut off the burners). The fault condition must be identified and rectified and the thermostat manually reset. Isolate the electrical supply to the heater and open the controls section door. Push in the red button on the fan/limit thermostat (located towards the top of the compartment) to reset. On NVx90

- 140 units also reset the second limit thermostat. Note: The thermostat 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.

5. Maintenance

To maintain efficient, reliable and safe operation of the heater it must serviced by a qualified person at least annually and preferably at the end of the heating season.

6. 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. If at any time a gas leak is suspected turn OFF the gas supply

- DO NOT USE A NAKED FLAME - and contact the local gas undertaking immediately.

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 field of Gas 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 office for expert advice. Your safety is paramount to us.

Gas Safety (Installation & Use) (Amendment) Regulations

It is law that all gas appliances are installed, adjusted and, if necessary, converted by qualified persons* in accordance with the current issue of the above regulations. Failure to install appliances correctly can lead to prosecution. It is in your own interests and that of safety to ensure that the law is complied with. * An approved class of person listed on the gas register.

Users Instructions

Page 4

CONTENTS

Section Title Page

Introduction 1

2. Technical Data 2

3. General Requirements 6

4. Installation 7

5. Air Distribution System 10

6. Commissioning & Testing 10

7. Servicing 12

8. Functional Flow Diagram 15

9. Connections to External Controls 17

10. Fault Finding Flow Chart 19

11. Short List of Parts 20

Tables Title Page

1. Dimensions 3

2. Specifications 3

3. Electrical Loadings 1ph 4

3.1 Injector Sizes & Burner Pressures Natural Gas - Group H - G20 5

3.2 Injector Sizes & Burner Pressures Propane - G31 5

Figure Title Page

1a. Exhaust only system - horizontal 8 1b. Exhaust only system - vertical 8 2a. Individual system - horizontal 9 2b. Individual system - vertical 9

3. General Controls Layout 10

4. Governor adjustment (Honeywell VR425A) 11

5. Governor adjustment (Honeywell VR4605A) 11

6. High/Lo Regulator 11

7. Modulating Regulator 12

8. Flame Current Measurement 12

9. Ignition Electrode Spark Gap 13

10. Thermostat Fan / Limit - Honeywell L4064N 13

Installation & Servicing Instructions

Page 5

1. INTRODUCTION

The NVx range are highly efficient gas fired, fanned circulation air heaters that cover heat outputs of 10kW to 140kW, have a closed combustion circuit and are supplied complete with a flue system. They are certified for use on Natural Gas, Group H G20, and Propane - G31 only. Appliance Categories are Cat II2H3P (GB, IE).

The heaters are designed to be suspended from suitable roof points or alternatively to be mounted on purpose designed brackets and are intended primarily for heating commercial or industrial premises. NVx heaters feature a closed combustion circuit and have an internal exhaust fan, mounted downstream of the heat exchanger, to evacuate the products of combustion and draw in air for combustion. The air heater must be connected to the flue system that is provided by Powrmatic Ltd. They may be used where the atmosphere inside the premises could be contaminated e.g. Dust, oil mist etc. but the heaters are not airtight and therefore may not be used in areas classified as hazardous as defined in BS 5345: Part 2 or areas subjected to significant negative pressures due to extract systems.

NVx/F heaters have an axial fan assembly fitted at the rear to circulate the air being heated through the folded tube heat exchanger. NVx/C units are supplied with a centrifugal fan and NVx/D units for use with ducted systems where the air moving fan is by others or a centrifugal fan section is used adjacent to or remote from the heater. NVx/DH units are for use in air handling units and NVx/EA units are for siting externally. Heaters are fitted as standard with inshot burners, a fully automatic control for ignition, flame sensing, gas supply control and safety functions, an internal exhaust fan, main air fan (/F and /C models), and fan/limit thermostat.

Options include High/Low or Modulating burner controls, inlet duct connection, outlet duct connection, 45° head, 90° outlet bend, vertical/horizontal outlet louvre assembly and a full range of modular duct components.

IMPORTANT

Service and Maintenance Engineers shall ensure that replacement items are fitted, adjusted and set in accordance with the data and detail set out in these instructions. If in doubt consult Powrmatic Technical Department.

Gas Safety (Installation & Use) Regulations 1998

Page 6

2. TECHNICAL DATA

R/H SIDE VIEW

A B

REAR VIEW

PLAN

FRONT VIEW

GAS ENTRY POINT

J CTRS

228 CTRS

122

ø D

NOTE: For dimensioning purposes both top and rear flue and combustion air connections are shown

R/H SIDE VIEW

REAR VIEW

PLAN

FRONT VIEW

J CTRS

228 CTRS

122

ø D

NOTE: For dimensioning purposes both top and rear flue and combustion air connections are shown

NVx

POWRMATIC

NVx

POWRMATIC

GAS ENTRY POINT

Page 7

NOTE: For dimensioning purposes both top and rear flue and combustion air connections are shown

33.733.7

R/H SIDE VIEW

REAR VIEW

PLAN

FRONT VIEW

J CTRS

228 CTRS

122

C T

ø D

NVx

POWRMATIC

GAS ENTRY POINT

Table 1. Dimensions

NVx

120

NVx

140

NVx

Model

NVx10

700

1000

1325

2325

785

540

760

912

700

760

831

975

422

637

932

1932

492

712

864

652

712

783

927

ØD E

233.5

24880

100

130

492

644

416

568

321

487

631

308

142

220

120

347

317

450

700

850

250

236

246

206

216

524

752

904

752

904

639

804

969

218

232.5

278

NVx

114

145

¾'’

194

225.5

297

374

260

326

398

297

S T

Gas inlet

Page 8

Table 3

Electrical Loadings 1ph

NVx

120

7.81 4.22

9.57 5.13

NVx

140

9.64 4.98

/F Models /C Models

MODEL

PLATE

AMPS

(A)

START

AMPS

(A)

RUN

AMPS

(A)

FUSE

RATING

(A)

NVx

0.18 0.34 0.16

870

2.8 4.2 2.10

1.39 0.51 4.0 8.1 2.60

NVx

0.38 0.28 4.0 7.8 3.20

NVx

1.83 0.61 14.7 4.50

NVx

1.30

2.56

1.35 8.4

14.5 5.00

NVx

1.40 4.01 1.96 3 16.0 6.40

NVx

4.70 2.44

NVx

4.78 2.51

2 x 1.40

NOMINAL

MOTOR

R.P.M.

PLATE

AMPS

(A)

START

AMPS

(A)

RUN

AMPS

(A)

FUSE

RATING

(A)

NVx

1.89 0.62

0.54

0.89

2.50

2 x 2.50

0.31

NOMINAL

MOTOR

R.P.M.

4.0 8.2 2.90

28.4 11.6

900

1400

775

910

820

900

11.1

2 x 8.4

2 x 11.1

24.5 10.6

42.5 21.5

24.5 12.3

NVx

Note: 3ph Data is supplied separately with units ordered to this specification.

14.0

39.8

5.30

25.2

Table 2 - Specifications

Note: /D data refers to Powrmatic supplied centrifugal/silencer duct section

MODEL

INPUT

(Nett)

OUTPUT

INPUT

(Nett)

OUTPUT

kW kW m³/s m³/h Pa kW

NVx10

10.79 10.0 6.57 5.90 0.2601

NVx15

16.00 15.0 8.22 7.50 0.3902

NVx20

21.85 20.0 11.58 9.92 0.5203

NVx25

27.32 25.0 16.50 14.30 0.6503

NVx30

32.60 30.0 18.34 16.30 0.7804

NVx40

43.48 40.0 24.19 21.22 1.0405

NVx50

54.23 50.0 28.40 24.83 1.3006

N/A 0.040 53

140

0.250

91.5

N/A

0.120

59.5

145 0.370 106.5 N/A 0.070 69.5

177 0.370 120.5

N/A 0.180 74.5

143 0.370 126.5

N/A 0.180 96.0

250 1.100 166.5

N/A 0.300 108.0

236 1.100 168.5

N/A 0.440 123.0 205 1.100

183

HIGH FIRE LOW FIRE

AIR

VOLUME

MAXIMUM

DUCT

RESISTANCE

FAN

MOTOR

WEIGHT

NVx60

65.22 60.0 35.63 31.49 1.5608

N/A 0.550 138.5 250 1.50

213

NVx75

NVx90

NVx120

81.5 75.0

97.8 90.0

130.4 120.0

42.61 37.50

58.50 54.50

75.45 71.00

1.9510

2.3412

3.1215

N/A 0.550 158.0 260 1.50 234

N/A 2 x 0.440 204.0

200 2 x 1.10 343

N/A 2 x 0.550 260

284 2 x 1.50 363.5

NVx140

152.1 140.0 98.92 92.55 3.6418

N/A 2 x 0.550 260

285 2 x 1.50 424

NOISE LEVEL

dB(A) @ 3m

N/A

NVx35

39.32 34.95 23.1 19.0 1.000

936

1405

1873

2341

2809

3746

4682

5619

7024

8428

11237

13110

3600

N/A 0.300 96.0

210 1.100 166.5

N/A

Page 9

Minimum

Inlet pressure

17.5mbar

Inlet

INJECTORS

High Fire

Low Fire

Pressure Burner

Gas Rate

Burner

Gas Rate

20mb Pressure Pressure

MODEL No. Size Marked mbar m³/h mbar m³/h mm

NVx10 4 1.36 240 13.8 1.14 5.3 0.69 NVx15 4 1.67 380 12.5 1.69 3.5 0.87 NVx20 4 1.94 500 12.7 2.31 3.4 1.26 NVx25 5 1.94 500 12.5 2.89 4.7 1.74 NVx30 6 1.94 500 13.6 3.45 4.0 1.94 NVx35 6 2.26 580 9.5 4.16 4.0 2.44 NVx40 8 1.94 500 13.5 4.60 4.0 2.56 NVx50 10 1.94 500 13.2 5.74 4.0 3.00 NVx60 8 2.54 750 9.5 6.90 2.5 3.47 NVx75 10 2.54 750 9.2 8.60 2.8 4.50

NVx90 6 3.5 1500 9.4 10.08 3.5 6.19 NVx120 8 3.5 1500 9.1 13.37 3.4 7.98 NVx140 10 3.5 1500 8.4 15.76 4.0 10.46

Inlet Pressure

37mbar

Table 4.1

Injector Sizes & Burner Pressures Natural Gas - Group H - G20 Net CV (Hi) = 34.02MJ/m³

Table 4.2

Injector Sizes & Burner Pressures - Propane G31 - Net CV (Hi) = 88.00MJ/m³

Inlet

INJECTORS

High Fire

Low Fire

Pressure Burner

Gas Rate

Burner

Gas Rate

37mb Pressure Pressure

MODEL No. Size Marked mbar m³/h mbar m³/h mm

NVx10 4 0.90 90 24.4 0.44 N/A N/A NVx15 4 1.20 120 21.6 0.65 5.8 0.34 NVx20 4 1.36 240 21.2 0.89 6.1 0.49 NVx25 5 1.36 240 21.4 1.12 7.9 0.67 NVx30 6 1.36 240 20.6 1.33 6.0 0.75 NVx35 6 1.36 240 20.5 1.61 9.2 0.95 NVx40 8 1.36 240 19.8 1.78 6.2 0.99 NVx50 10 1.36 240 21.2 2.22 5.7 1.16 NVx60 8 1.60 160 25.4 2.67 6.4 1.34 NVx75 10 1.60 160 25.1 3.32 7.2 1.74

NVx90 6 2.26 580 21.0 3.90 7.9 2.39 NVx120 8 2.26 580 21.1 5.17 7.7 3.08 NVx140 10 2.26 580 20.2 6.09 8.6 4.04

Page 10

3. General Requirements

3.1 Related Documents

The installation of the air heater(s) must be in accordance with the rules in force and the relevant requirements of the Gas Safety Regulations, Building Regulations and the I.E.E. Regulations for Electrical Installations. It should also be in accordance with any relevant requirements of the local gas region, local authority and fire authority and the relevant recommendations of the following documents.

Institution of Gas Engineers & Managers

IGE/UP/1 (Ed.2) Strength and tightness testing and purging of industrial and commercial gas installations. IGE/UP/1A Soundness testing and direct purging of small low pressure industrial and commercial gas installations. IGE/UP/2 Gas installation pipe work, boosters and compressors on industrial and commercial premises. IGE/UP/10 (with Amendments October 2010) Installation gas appliances in industrial and commercial premises.

British Standards Code of Practice

BS 5588 Fire precautions in the design and construction of buildings. Part 2 : 1985 Code of Practice for Shops Part 3 : 1983 Code of Practice for Office Buildings

BS 6230 Installation of Gas Fired Forced Convection Air Heaters for Commercial and Industrial Space Heating.

Those appliances having a gross input rating not exceeding 60kW viz. NVx10 to NVx50 inclusive and installed to take their combustion air from within the building must be installed in accordance with the relevant recommendations of the following document. BS 5440 Flues and Air Supply for gas appliances of rated input not exceeding 60kW (1st and 2nd family gases), Part 2 - Air Supply

For NV/D units of 10 - 50 size, reference should also be made to BS 5864 Code of Practice for installation of gas-fired ducted-air heaters of rated input not exceeding 60kW.

3.2 Location

The location chosen for the air heater must permit:

- provision of a satisfactory flue system and adequate air supply.

- adequate space for servicing and air circulation around the air heater. IMPORTANT:

1. Heaters shall not be installed in:a) Those parts of spaces within buildings that have been classified as hazardous areas as defined in BS EN 60079-10, Electrical apparatus for explosive gas atmospheres. Classification of hazardous areas. b) Where there is a foreseeable risk of flammable particles or gases or corrosion inducing gases or vapours being drawn into either the heated air stream or the air for combustion. In such cases installation may only proceed if the air to be heated is ducted to the heater from an uncontaminated source, preferably from outside the building. The option of taking combustion air from the space is not permitted. Where only airborne particles are present it may suffice to fit filters on the main air inlet duct of the heater and advice may be obtained from Powrmatic Ltd. c) Particular care should be taken to ensure chlorine vapours (from Freon, degreaser compounds etc.) are not induced into the combustion air stream as severe heat exchanger damage will result. d) In areas subjected to significant negative pressures due to extract systems.

Where the location of the air heater is such that it might suffer external mechanical damage e.g. from overhead cranes, fork lift trucks, it must be suitably protected. NVx units are designed to operate within an ambient temperature range of -10 to 25°C.

3.3 Gas Supply

3.3.1 Service Pipes

The local gas undertaking should be consulted at the installation planning stage in order to establish the availability of an adequate supply of gas. An existing service pipe must not be used without prior consultation with the local gas undertaking. The inlet gas pressure under running conditions must not be less than 17.5mb.

3.3.2 Meters

An existing meter should be checked, preferably by the gas undertaking, to ensure that the meter is adequate to deal with the total rate of gas supply required by all connected equipment.

3.3.3. Installation Pipes

Installation pipes should be fitted in accordance with IGE/UP/2. Pipe work from the meter to the air heater must be of adequate size. Do not use pipes of a smaller size than the inlet gas connection of the heater. The complete installation must be tested for soundness as described in the above Code.

3.3.4. Boosted Supplies

Where it is necessary to employ a gas pressure booster the controls must include a low pressure cut off switch at the booster inlet. The local gas undertaking must be consulted before a gas pressure booster is fitted.

3.4 Flue System

Only flue systems supplied through Powrmatic Ltd may be used with NVx units and they comprise of Muelink & Grol terminals and twin to concentric adapters and SFL SUPRA straight lenghts and elbows. Several configurations of flue and combustion air ducts are available (See Page 7 & 8 Figs 1a to 2b). The flue 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.

3.5 Combustion Air Supply

Air inlet grilles shall be provided at low level when combustion air is taken from within the space being heated and the building has a design air change rate less than 0.5/h, and NVx units are installed in heated spaces having a volume less than 4.7 m³/kW of total rated heat input:(1) for heaters of heat input less than 60 kW, the total minimum free area shall not be less than 4.5 cm² per kilowatt of rated heat input. (2) for heaters of heat input 60 kW or more, the total minimum free area shall not be less than 270cm² plus

2.25 cm² per kilowatt in excess of 60 kW rated heat input. Where the air heater(s) are to be installed in a plant room the plant room must have permanent air vents communicating directly with the outside air, at high level and at low level. Where communication with the outside air is possible only by means of high level air vents, ducting down to floor level for the lower vents should be used. All air vents should have negligible resistance and must not be sited in any position where they are likely to be easily blocked or flooded or in any position adjacent to an extraction system which is carrying flammable vapour. Grilles or louvres should be so designed that high velocity air streams do not occur within the plant room. The basic minimum effective area requirements of the air vents

Page 11

4. Installation of Air Heater(s)

4.1 General

Before installation

1) Check that the local distribution conditions, nature of gas and pressure, and adjustment of the appliance are compatible.

2) Check that the local electrical supply conditions are compatible with the electrical data given on the data plate.

For NVx/D units the normal air flow direction is from right to left when viewing the heater from the burner/controls end with the fan unit upstream. The following minimum clearances must be observed for installation and servicing . RHS Clearance (looking at front of heater) 1.0m LHS Clearance (looking at front of heater) 0.2m Top of the heater to ceiling 0.2m Rear of heater to nearest wall 0.4m (Depending on flue system used) For multi air heater installations the following minimum distances between units must be observed. Between units, side to side 3.0m Between units, back to back 3.0m Recommended mounting heights, floor level to the underside of the unit, are:NVx10 - 30F 2.5m - 3m NVx40F - 150F 3m - 5m NVx/D Models Mounting heights not applicable All models must not be installed at a height of less than 2.5m to the base of the unit. Any combustible material adjacent to the air heater and the flue system must be so placed or shielded as to ensure that its temperature does not exceed 65 °C.

When NVx modular components are used in conjunction with the heater each component must be individually supported.

4.2 Fitting the Air Heater

Note: The access door to the controls section may be removed to improve access. Open the door to 90°, remove the earth cable at the bottom, and then lift the door vertically upwards to disengage the hinge plates. Refit in reverse order. Ensure that the earth cable is refitted. The air heater may be installed either: a) suspended from suitable vertical drop rods or chains. b) on specifically designed cantilever brackets from a noncombustible wall. c) on a level noncombustible surface. The surface must not extend past the front edge of NVx/F heaters. The method of installation must be capable of adequately supporting the weight of the unit (See Table 2, Page 3) 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 effects of rust or corrosion. Raise the heater up to the point of installation using suitable and safe means and connect to the means of suspension. Note: Each heater is provided with additional central suspension points that can be used to provide temporary support, using suitable means, whilst the unit is being installed. Under no circumstances must these points be used as the final means of suspension. Threaded drop rods must have lock nuts fitted that are tightened down onto the 10mm fixings in the heater. If reducing noise levels is important the heater should be insulated from the structure by installing it on suitable anti-vibration mountings. In all such cases and when the heater is suspended it is essential that all gas, duct, and electrical

are as follows: (a) Low Level (inlet) (1) for heaters of total rated heat input less than 60kW: 9cm² per kilowatt of rated heat input. (2) for heaters of total rated heat input 60kW or more: 540 cm² plus 4.5 cm² per kilowatt in excess of 60 kW total rated input.

(b) High Level (outlet) (1) for heaters of total rated heat input less than 60kW:

4.5cm² per kilowatt of rated heat input. (2) for heaters of total rated heat input 60kW or more: 270 cm² plus 2.25 cm² per kilowatt in excess of 60kW total rated input.

3.6 Air Distribution System

Where single NVx/F units are required to cover a large floor area, and in buildings with high roof or ceiling heights Calecon thermal economiser units should be fitted to ensure even heat distribution and minimise stratification. Care should be taken to avoid impeding the air throw with racking, partitions, plant or machinery etc. Various outlet configurations 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 filters, jointing and any insulation or lining must be constructed entirely of materials which will not contribute to a fire, 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 fire-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 fire 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.

3.7 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 NVx/C and fan/silencer units can also be supplied for 400V 3N, 50Hz.

Page 12

connections to the heater are made with flexible connections to maintain continuity of connection.

4.3 Flue/Combustion Air Duct System

The minimum distance between surfaces of the flue pipe and any surfaces made from combustible materials is 300mm. If it is necessary for the flue pipe to bass through a structure made from combustible materials a metal sleeve must be used so that the minimum clearance of 300mm is maintained. The flue and combustion air ducts supplied with the heater are capable of withstanding their own weight over the allowable flue lengths. Wall bands and bracing brackets, or equivalent, must be used to provide lateral stability and should be used at centres not exceeding 2.5 metres. All models are supplied as standard with a rear flue outlet and the flue outlet and combustion air sockets temporarily fitted.

4.3.1.1. Conversion to Top Flue Outlet

1. Remove the two blanking plates from the flue /combustion air openings at the top of the unit.

2. Remove the four screws from the exhaust fan outlet flange.

3. Remove the screws securing the fan mounting box to the exhaust header plate.

4. Remove fan assembly and rotate the assembly 90° anticlockwise. 5 Refit the fan assembly to the exhaust header plate ensuring that the gasket is not damaged, if necessary replace or make good with silicon sealant.

6. Secure the exhaust fan outelt flange to the underside of the top panel and fit the blanking plates to the rear panel.

4.3.1.2 Fitting Flue/Combustion Air Sockets

1. Apply a bead of silicon sealant around the face of the flange on the exhaust fan outlet tube that can be seen from the outside of the heater. Place the flue socket on the outside of the heater to mate with this flange and clamp the two flanges together, on either side of the heater panel using the screws provided. Ensure that the silicon sealant has sealed between the two flanges.

2. Apply a bead of silicon sealant around the face of the flange of the combustion air socket, on the same side as the socket. Passing the socket through the panel from the inside, position the flange up against the panel. Secure, from the outside, with the screws provided.

3. If ducted combustion air is not required (see Section 3.5) fit the mesh inlet plate behind the unused combustion air inlet hole.

4. Apply silicon sealant and refit blanking plates as required to seal unused panel holes.

4.3.2. General Requirements

See Figures 1a to 2b for the different types of flue installation. In all cases the flue outlet socket must be connected via the provided flue system to outside air. The maximum permitted length of flue system is 6m, or 12m if the flue outlet only is used. If an offset is required two sets of 45° bends should be used each set being equivalent to 0.5m of flue length. 90° bends may be used but each set will be equivalent to 1.0m of flue length. The minimum flue length (end of flue terminal to back or top of heater) shall not be less than 1.0m for the NVx10 - 50 and 1.3m for the NVx60 - 140. All outer joints must be finished with the provided locking bands. A smear of silicon grease to the inside of sockets will assist in fitting components together. All flue and combustion air ducts must be supported independently of the air heater. The flue or flue/combustion air terminal must not be installed so as to be 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.

4.3.3 Installation of Flue System

Note: A terminal guard, as supplied by Powrmatic Ltd, must be fitted to horizontal flue terminals. The minimum flue length in all cases is

4.3.3.1 Horizontal System - Rear Outlet

Note: If the outlet is required to the side of the unit 90° bends may be fitted directly onto the inlet/outlet spigots on the heater.

1. Locate the position of the flue terminal, allowing for a slight gradient running down from the heater to the terminal of 2° 3° and cut a hole to suit.

2. Fit the flue terminal, securing via the wall plate and weather with silicon sealant or similar.

3. Fit the twin to concentric adaptor to the terminal section and extend the flue and combustion air ducts to the heater using straight lengths. Fit an adjustable length prior to the unit, to facilitate flue disconnection for servicing. Extend the adjustable lengths to make the final connection to the appropriate heater inlet/outlet spigots.

4. Ensure that internal silicon sealing rings are in place and that all tubes are pushed fully home. Secure concentric lengths with

Fig 1b Exhaust only system - vertical

Terminal

Lengths

Adjustable length

Flashing

Flue socket

Combustion air entry

(fitted with inlet grille)

Condensate drain length

Fig 1a Exhaust only system - horizontal

Terminal

Lengths

Adjustable length

Flue outlet

Combustion air entry

(fitted with inlet grille and inlet bend (not shown))

12m maximum, Minimum 980mm

Combustion air entry

(fitted with inlet grille)

Note: A terminal guard may be required.

Combustion air entry

(fitted with inlet grille and inlet bend (not shown))

Maximum 12m Minimum 80Ø - 1480mm 100Ø - 1560mm 130Ø - 1860mm

Page 13

the locking bands provided.

4.3.3.2 Vertical System - Top Outlet

1. Locate the position of the flue terminal cut a hole in the roof to suit.

2. Fit the flashing and the flue terminal so that the lower edge of the outer case is over the top of the flashing. Weather with silicon sealant or similar. Fit a condensate drain length into the flue socket on the heater and an equivalent straight length onto the combustion air socket.

3. Fit the twin to concentric adaptor to the terminal section and

Notes for all systems.

i) Final overall length of adjustable disconnection piece must be

between 360 - 415mm.

ii) 45° offsets may be used if required. Each set is equivalent to

0.5m of flue length.

iii) Where NV heaters are used in clean environments it is

permissible to take the combustion air directly from the heated space. The supplied mesh intake plate, must be fitted to the combustion air inlet on the rear of the heater.

then extend down to the heater using straight lengths. Fit adjustable lengths as the final connection pieces, to facilitate flue disconnection for servicing. Extend the adjustable lengths to make the final connection but do not exceed the maximum extended length so as to maintain joint integrity. Extend the drainage off take of the condensate drainage length to a suitable gully or drain.

4. Ensure that internal silicon sealing rings are in place and that all tubes are pushed fully home. Secure concentric lengths with the locking bands provided.

4.3.3.3 Internal Combustion Air Systems

1. Complete the run of flue sections from the terminal spigot to the flue outlet socket of the heater generally as described in

4.3.3.1 and 4.3.3.2, ensuring that the internal silicon sealing rings are in place.

2. It is recommended that both air inlets are utilised and that both are fitted with the mesh inlet plates supplied. In addition a 90° bend should be fitted to the rear inlet, the inlet opening of the bend facing to the side of the heater i.e. away from the main air fan.

4.4 Gas Connection

A servicing valve and union to facilitate servicing must be fitted to the gas inlet pipe work of the heater. The gas supply must be completed in solid pipe work and be adequately supported. Heaters suspended by drop rods, straps or chains must have a flexible connection as the final link between the gas supply pipe work and the heater. Sufficient slack must be left in the connection to take account of normal movement of the heater.

Warning

When completing the final gas connection to the heater do not place undue strain on the gas pipe work of the heater.

4.5 Electrical Connections

All units, with the exception of NVx/D units supplied with a centrifugal fan/silencer duct section, are fully prewired and only require final connections for the incoming mains supply and completion of the control circuit (230V) via a room thermostat, time clock etc. and the remote low level lockout reset. Warning: Lockout reset is by a switched Neutral to the controls in the heater. All units must be earthed. See Table 4 (Page 4) 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. See the wiring diagram accompanying these instructions. NVx/D models supplied with a centrifugal fan/silencer duct section require wiring to be completed between the heater and fan. Refer to supplied wiring diagram. NVx/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 the heater terminal marked “Live Main Fan” 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 not be taken direct from the internal wiring of the NVx heater.

Fig 2b Individual system - vertical

Maximum 6m Minimum 80Ø - 1480mm 100Ø - 1560mm 130Ø - 1860mm

Terminal

Lengths

Adjustable lengths

Single to twin adaptor

Flashing

Flue socket

Combustion air socket

Condensate drain length

Fig 2a Individual system - horizontal

Terminal

Lengths

Adjustable length

Single to twin adaptor

Flue socket

Combustion air duct

Maximum 6m, Minimum 980mm

Combustion air socket

Note: A terminal guard may be required.

Page 14

Figure 3 General Controls Layout

Exhaust Fan (F)*

Burner

Assembly

Fan/Limit

Thermostat (B)*

Brahma

Control (A)*

Main Fuse

(3.15A) (L)*

Brahma

Control

Fuse (4A)

Gas

Valve (E)*

Ignition

Electrode (J)*

On (O)* and

limit indicator

lights (C)*

Rectification

Electrode (J)*

Internal lockout

indicator

and reset

switch (N)*

Air Pressure

Switch (APS)

(D)*

* Refers to

functional flow

diagrams

APS

Sensing

Tube

5. Air Distribution System

5.1 General

NVx/D and NVx/C models are designed for use with duct work to more precisely define 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 joints between NVx ancillary components must be securely fastened and made airtight using appropriate sealants or sealing strips. If required the duct work should be insulated to reduce heat loss.

5.2 Noise Reduction

Ducting should be connected to the heater spigots via an airtight flexible coupling of noncombustible material. Before fitting 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 fitted 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.

5.3 Room Thermostat Siting

The room thermostat should be fitted 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, should be avoided. The thermostat should be mounted about 1.5m from the floor. 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 the accompanying wiring diagram.

6. Commissioning & Testing

6.1 Electrical Installation

Checks to ensure electrical safety must be carried out by a qualified person.

6.2 Gas Installation

For new installations the whole of the gas installation, including the meter, should be inspected and tested for soundness and purged in accordance with the recommendations of IGE/UP/1 (Edition 2) or IGE/UP/2A as appropriate.

6.3 Air Distribution System

The system should be checked to ensure that the installation work has been carried out in accordance with the design requirements. Particular attention should be given to the correct arrangement of delivery ducts and registers, return air ducts and grills and general adequacy of return air paths. For NVx/D and NVx/C units ensure that the duct work is balanced so that the specified motor running currents are achieved See Table 3, Page 4.

6.4 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 all external controls are calling for heat. d) If an MC200 or Powrtrol is being used ensure that the control is set to Winter operation.

Page 15

Figure 4

Governor adjustment screw under cover cap (Honeywell VR425AB1007)

Figure 5

Governor adjustment screw under cover cap (Honeywell VR4605A B1027)

NVx NVx NVx NVx NVx NVx NVx NVx NVx NVx NVx NVx NVx

Model 10 15 20 25 30 35 40 50 60 75 90 120 140 Natural Gas G20 High Fire CO2% 6.7 7.3 7.4 7.3 7.8 8.25 7.7 8.7 8.1 8.8 7.4 8.7 8.3 Low Fire CO2% 3.7 3.1 3.2 3.7 3.7 3.6 3.6 3.5 3.4 3.6 3.9 4.4 4.6 Propane G31 High Fire CO2% 7.3 7.9 8.5 8.1 9.1 9.2 9.3 9.5 9.1 9.7 8.5 10.1 8.0 Low Fire CO2% 4.1 3.8 3.7 4.1 4.1 3.9 4.3 4.0 3.9 4.1 4.5 5.0 4.0

Fig 6 High/Low Regulator

Cover Lever point

Hexagonal adjustment screw for maximum pressure setting

Internal slotted adjustment screw for minimum pressure setting

6.5 Lighting the Air Heater

NOTES:

1. On initial lighting of the heater(s), it may take some time to purge the internal pipe work of air.

IMPORTANT:

The internal pipe work of the appliance has been tested for soundness before leaving the factory. After establishing the main burners test round the gas inlet connection using a leak detection fluid e.g. soap solution.

6.5.1 All Models

1. Switch on the electrical supply at the isolator and the ignition sequence will commence. After a delay of approximately 45 seconds the ignition spark will be generated and the main gas valves energized. The burners will then light.

2. If the burners fail to light the control box will complete a further four ignition attempts. If at the end of five attempts the burners have still not lit the control box will go to lockout and both the internal and remote lockout lights will be illuminated. To restart the ignition sequence depress the illuminated reset button for about 1-2 seconds.

3. SHUT OFF Switch OFF the electrical supply to the heater or set the clock control to OFF or set the room thermostat to MIN.

6.6 Adjustments

6.6.1 Burner Gas Pressure

This is set for the required heat input before despatch. In the case of Hi/Lo and Modulating units both high and low pressures are set. Pressures should be checked in the following manner.

6.6.1.1 Standard Units

1. Set external controls to ensure that the main burner is off. Open the side access door. Connect a pressure gauge to the burner pressure test point on the multifunctional control.

2. Set external controls so as to turn on the main burner. Compare the measured burner gas pressure to that stated on the data plate. If necessary adjust the burner gas pressure by turning the

regulator screw anticlockwise to decrease the pressure, or clockwise to increase the pressure.

3. In addition it is advisable to check the gas rate using the gas meter dial pointer. Ensure that no other appliances supplied through the meter are in operation. If required, after checking or setting the burner pressures, the CO

content in the flue gases can be checked by sampling in the first section of flue fitted to the flue outlet of the unit. Nominal CO2 values are given for guidance in the Table at the bottom of the page.

5. Turn off the main burner as in 6.5.1. and disconnect the pressure gauge and replace the sealing screw. Turn on the main burner as above and test for gas soundness around pressure test joint using a leak detection fluid e.g. soap solution.

6.6.1.2 High/Lo Regulator

1. Set external controls to ensure the main burner is off. Open the side access panel. Connect a pressure gauge to the burner pressure test point on the multifunctional control.

2. Set external controls to turn on the main burner and maintain high fire. Compare the measured burner gas pressure to that stated on the data plate. In addition it is advisable to check the gas rate using the gas meter dial pointer ensuring that no other appliances supplied through the meter are in operation.

3. Repeat 2 above with external controls set to maintain low fire.

4. If it is necessary to adjust either the high fire or low fire pressures proceed as follows after levering off the plastic cover from the Hi/Lo regulator. Note: High fire setting must be adjusted first after which the low fire setting can be set. Any adjustment of the high fire setting alters the minimum setting.

Maximum Setting

With the controls set to high fire use an adjustable or 8mm spanner to turn the adjustment screw for high fire pressure, clockwise to increase and counter-clockwise to decrease, until the required pressure is obtained. Turn the burner On and OFF several times to check the pressure setting and then turn off. Minimum Setting Disconnect electrical connection of high/low regulator and turn burners back on and wait until the burner pressure has stabilised. Use a screwdriver to turn the slotted adjustment screw for low fire pressure, clockwise to increase and counter-clockwise to decrease, until the required pressure is obtained.

Page 16

Reconnect high/low regulator and check high fire pressure. Repeat both steps if necessary and then replace cover cap.

5. Turn off the main burner, disconnect the pressure gauge and replace the sealing screw. Turn on the main burner and test for gas soundness around pressure test joint using a leak detection fluid. Replace access panel.

6.6.1.3 Modulating Regulator

1. Set external controls to ensure that the main burner is off. Open the side access panel. Connect a pressure gauge to the burner pressure test point on the multifunctional control.

2. Set external controls so as to turn on the main burner and maintain high fire. Compare the measured burner gas pressure to that stated on the data plate. In addition it is advisable to check the gas rate using the gas meter dial pointer ensuring that no other appliances supplied through the meter are in operation.

3. Repeat 2 above with external controls set to maintain low fire.

4. If it is necessary to adjust either the high fire or low fire pressures proceed as follows after removing the plastic cover from the Modulating regulator. Note: Mimimum fire setting must be adjusted first after which the high fire setting can be set. Any adjustment of the minimum fire setting alters the maximum setting.

Minimum Setting

Disconnect electrical connection of modulating regulator and turn burners back on and wait until the burner pressure has stabilised. Turn 9mm adjustment nut for low fire pressure clockwise to increase and counter-clockwise to decrease until the required pressure is obtained. Reconnect modulating regulator and check high fire pressure, readjust if necessary.

Maximum Setting

Disconnect electrical connection of modulating regulator and turn burners back on and wait until the burner pressure has stabilised. Push shaft gently downards to the maximun adjustment screw and hold there. Turn 7mm adjustment nut for high fire pressure, clockwise to increase and counter-clockwise to decrease, until the required pressure is obtained. Release shaft. Repeat both settings if necessary and then replace cover cap.

6.6.2 Flame Current

1. To measure the flame current connect a multimeter capable of measuring micro amps as shown in the following diagram.

2. Minimum current reading is 0.5mA and normal value should be 1.5mA or higher.

6.6.3 Air Heater Controls

1. Close the gas service tap and ensure that the gas valve is heard to close within 1 second and that the lockout light is illuminated. Note that the heater may attempt five reignition before going to lockout. Open the gas service tap and reset the unit from lockout.

2. Check that the room thermostat and all automatic controls are operating satisfactorily.

6.7 Handing over the Air Heater

Hand these instructions to the user or purchaser for retention and instruct in the efficient and safe operation of the air heater and associated controls. Adjust the automatic controls to those values required by the User. Finally, advise the user or purchaser that, for continued efficient and safe operation of the air heater, it is important that servicing is carried out annually. In the event that the premises are not yet occupied turn off the gas and electricity supplies and leave instructional literature adjacent to gas meter.

7. Servicing

WARNING: Always switch off and disconnect electricity supply and close the gas service valve before carrying out any servicing work or replacement of failed components. NOTE: If a suspended air heater is to be serviced do not lean ladders against the heater. Ensure that an access tower or equivalent is used. NOTE: The access door to the controls section may be removed to improve access. Open the door to 90°, remove the earth cable at the bottom, and then lift the door vertically upwards to disengage the hinge plates. Refit in reverse order. Ensure that the earth cable is refitted.

7.1 General

Full maintenance should be undertaken not less than once per year by a qualified person. After any servicing work has been complete, or any component replaced, the air heater(s) must be fully commissioned and tested for soundness as described in Section 6.

7.2 Main Burner Assembly Removal

1. Ensure that the gas service valve is turned OFF and then unscrew the union nut situated immediately down stream of it.

2. Disconnect the spark and rectification leads from the control box and remove the electrical plug connections from the top of the gas control valve assembly.

3. Remove the burner heat shield, 3 screws

4. Release the inlet connection flange from the gas valve by

Fig 7 Modulating Regulator

‘O’ ring

Adjustment nut (9mm) for minimum pressure setting

Adjustment nut (7mm) for maximum pressure setting

Cap

Shaft

6.3mm AMP terminals

Micro ammeter

J5 J6

I ion

JT2

Ignition

Ionisation

JT1

Fig 8 Flame Current Measurement

Page 17

removing the four screws.

5. If required remove the manifold by removing the four screws securing it to the burner assembly.

6. Remove the two screws that secure the top of the burner assembly to the bulkhead and lift out burner assembly

7. Using a stiff brush, not a wire brush, brush the burners to dislodge accumulated deposits. Inspect the burners both internally and externally to ensure that they are clean. Examine the injectors and if damaged or deteriorated, replace with new ones of the correct size and marking. If deemed necessary, clean the injectors. Do not broach out with wire.

8. Reassemble the injectors, manifold and burners in reverse order to that above.

7.3 Ignition and Rectification Electrodes

Note: The ignition electrode is located at the bottom of the burner assembly, the rectification electrode is located at the top of the burner assembly.

1. Inspect the electrodes, making sure that they are in a sound and clean condition. In particular check that the ignition electrode is clean and undamaged. Check that the spark gap is 2.5mm and that the rectification probe is 10 - 12mm forward of the burner.

Fig 9 Ignition Electrode Spark Gap

7.4 Heat Exchanger

Whilst the main burner assembly is removed from the unit check that the primary sections that the burners fire into are clean.

7.5 Main Fan Assembly

7.5.1 NVx/F & /C Models

1. Inspect the fan blades for any damage or excessive build up of deposits that could give rise to an imbalance. Remove the assembly for cleaning as follows.

2. Slacken the cable gland on the heater casing through which the fan electrical cable passes.

3. Disconnect the fan leads from the electrical terminals.

4. Withdraw cable through entry grommet.

5. Remove the fan and motor assembly complete by removing the hexagon headed screws that secure the fan to the rear panel.

6. Reassemble in reverse order.

7.5.2 Centrifugal Fan/Silencer Section

1. Remove section side panel(s) and inspect the fan blades for any damage or excessive build up of deposits that could give rise to an imbalance. Remove the assembly for cleaning as follows.

2. Slacken the cable gland on the casing through which the fan electrical cable passes.

3. Disconnect the fan leads from the electrical terminals in the contactor enclosure.

4. Withdraw cable through entry grommet.

5. Remove the complete fan assembly by removing the fixings securing the fan to the base rails.

6. Reassemble in reverse order.

7.6 Replacement of Faulty Components

7.6.1 Multifunctional Control

1. If there is movement available on the incoming gas pipe work e.g. a flexible connection has been used go to step 2 otherwise remove the burner assembly as previously described in Section

7.2

2. Remove the electrical plug connections from the top of the multifunctional control.

3. Release the flanged connections at the inlet and outlet of the multifunctional control and remove the multifunctional control.

4. Reconnect the new valve in the reverse order to that above ensuring that the valve is correctly orientated. Renew the sealing 'O' rings if necessary.

7.6.2 Burners

1. Remove the burner assembly as described in Section 7.2.

2. Remove the end plates of the burner assembly and the central burner support plate.

3. Exchange burners as required and reassemble components in reverse order.

4. Re-commission the appliance as described in Section 6.

7.6.3 Electrode Assemblies

1. Disconnect the electrode leads from the DMN control box as appropriate.

2. Remove the screw securing the electrode assembly to the burner assembly side plate and withdraw the assembly.

3. Fit replacement and reassemble in reverse order. Check that the spark gap is 2.5mm (See Fig. 8) and the rectification electrode is 10 - 12mm forward of the burner.

7.6.4 Fan/Limit Thermostat

Thermostat settings: Fan Off Fan On Limit NVx 10 - 140 30°C 50° 100

1. Release the screw securing the thermostat casing to the body, squeeze the casing sides inward and pull casing forward.

2. Remove the electrical connections from the thermostat.

2.5mm

3. Remove the screws securing the thermostat to the bulkhead and withdraw.

4. Fit replacement thermostat in reverse order.

Important: In this application the brass link is removed. Note: NVx 10 to NVx 75 units have one fan/limit thermostat

whereas NVx 90 to NVx 140 units have two. The second thermostat is at the opposite end of the heater to the burner/controls end. The fan circuits are wired in parallel (either thermostat will turn on the fan) and the limit thermostats are wired in series (either thermostat will shut down the burner)

Fig 10 Thermostat Fan / Limit - Honeywell L4064N

CAUTION

DO NOT ROT ATE - HOLD

DIAL WHEN SETTING POINTERS

Limit Set point Adjustment

Fan Circuit

OUT

Limit Circuit

OUT

Limit Reset

Fan ON

Override

Set Point Dial

Brass Link Location

Mechanical Limiter

Release Point

Mechanical limiter

Fan OFF Set point Adjustment

Limit Circuit

Fan Circuit

Fan ON Set point Adjustment

Page 18

7.6.5 Exhaust Fan

1. Remove the four screws securing the flue outlet socket.

2. Disconnect the fan electrical connections from the main terminal strip

3. Remove the screws securing the fan mounting box to the exhaust header plate.

4. Remove fan assembly.

5. If needed transfer the fan mounting box to the replacement fan.

6. Fit replacement exhaust fan, using new gaskets and silicon sealant as necessary, and reassemble in reverse order.

7.6.6 Air Pressure Switch

1. Remove the two screws securing the cover and remove cover.

2. Disconnect electrical connections.

3. Pull off the sensing tube from the air pressure switch.

4. Note the setting of the old pressure switch.

5. Remove the screws fixing the air pressure switch and remove switch.

6. Fit replacement in reverse order refitting the sensing tube to the negative (- or L) tapping on the pressure switch. Adjust setting to that of the old pressure switch.

7.6.7 Control Box

1. Unplug all the electrical connections.

2. Remove the four screws that secure the control box in place.

3. Fit replacement in reverse order.

7.6.8 Centrifugal Fan/Motor

1. Disconnect the electrical connections to the centrifugal fan section.

2. Remove the side panels of the section for access to the fan and motor.

3. Fit replacements as appropriate and reassemble in reverse order. Note: If a 3ph motor is being replaced ensure that the direction of rotation is correct. If it is not interchange any two of the three phases connected to the motor.

Page 19

FUSE

JT2

JT1

BRAHMA

CODE 3756400 Type DMN3 2

RED

°C °C

4 5 6

Br 0.5

Blu 0.5

Br 0.5

Blu 0.5

Blu 0.5Br 0.5

Or 0.5

FAN

LIMIT

Or 0.5

Yel 0.5

Wh 0.5

Blk 0.5

Br 0.5

Blk 0.5

Grey 0.5

Wh 0.5

Blu 0.5

Blk 0.5

Wh 0.5

Blu 0.5

J K

Or 0.5

Yel 0.5

Or 0.5

Live

Neutral

15 17 18

1413

1 2 3 4 5 6 7

16 17 18 19 13 14 15

12 11

GREEN

8. Functional Flow Diagram

8.1 NVx10 - 75 Basic Unit

A. Brahma Control DMN32 B. Honeywell Fan/Limit Thermostat C. Red Neon Indicator D. Air Pressure Switch LGW3 A2 E. Main Gas Valve F. Exhaust / Combustion Fan

G. Main Fan J. Ignition Electrode K. Rectication Probe L. Fuse 3.15A N. Internal Lockout Reset Button O. Green Neon Indicator

Terminals 1 - Heat demand (230V input) 2 - Main Fan only operation (230V input) 3 - For use on High/Lo & Modulating Units 4 - For use on Modulating Units 5 - Lockout Indication (230V output) 6 - Lockout Reset (Switched to Neutral)

Notes:

Represent NVx Terminalsa)

b) NVx terminals 3 & 4 are used in High/Lo and Modulating units c) Earth connections are not shown

3.15A FUSE

Page 20

A. Brahma Control DMN32 B. Honeywell Fan/Limit Thermostat C. Red Neon Indicator D. Air Pressure Switch LGW3 A2 E. Main Gas Valve F. Exhaust / Combustion Fan

G. Main Fans J. Ignition Electrode K. Rectication Probe L. Fuse 3.15A N. Internal Lockout Reset Button O. Green Neon Indicator

FUSE

JT2

JT1

BRAHMA

CODE 3756400 Type DMN3 2

RED

°C °C

4 5 6

Br 0.5

Blu 0.5

Br 0.5

Blu 0.5

Blu 0.5Br 0.5

Grey 0.5

Blk 0.5

FAN

LIMIT

Or 0.5

Yel 0.5

Wh 0.5

Blk 0.5 Or 0.5Grey 0.5

Yel 0.5

Br 0.5

Blk 0.5

Wh 0.5

Blu 0.5

Blk 0.5

Wh 0.5

Blu 0.5

J K

Or 0.5

Live

Neutral

15 17

1413

1 2 3 4 5 6 7

16 17 18 19 13 14 15

12 11

GREEN

8.2 NVx90 - 140 Basic Unit

Notes:

Represent NVx Terminalsa)

b) NVx terminals 3 & 4 are used in High/Lo and Modulating units c) Earth connections are not shown

3.15A FUSE

°C °C

FAN

LIMIT

Page 21

9. Connections to External Controls

Note: To comply with ECA requirements and to achieve maximum system eciency it is recommended that NVx units are controlled by an MC200 Fuel Saver unit. Simple room thermostat and room thermostat/time clock control systems will not provide optimum system eciency and fuel savings.

NEUTRAL

LIVE

EARTH

NVx HEATER (ON/OFF)

L N E

2 3 4 5 6

Note: MC200

internal sensor

is removed

Remote Sensor

(optional)

T1 3 T2 1

MC200 FUEL SAVER

RESET

IN 2

COM

SEN 1

0-10V+

0-10V-

Lockout

Fan In

Heat Hi In

Heat Hi Out

Heat Lo In

Heat Lo Out

Fan Out

L Out

SUPPLY IN Mod Out

Hi/Lo NVxOn/O NVx

Modulating NVx

NVx HEATER (Hi/Lo)

Remote Sensor

(optional)

T1 3 T2 1

MC200 FUEL SAVER

RESET

IN 2

COM

SEN 1

0-10V+

0-10V-

Lockout

Fan In

Heat Hi In

Heat Hi Out

Heat Lo In

Heat Lo Out

E L

Fan Out

L Out

SUPPLY IN Mod Out

NEUTRAL

LIVE

EARTH

Note: The NVx Heater and MC200 may be fed by separate electrical supplies providing both supplies are the same phase.

Warning: If external controls are not isolated 230V may be present at heater terminals even when the heater is isolated.

MC200 FUEL SAVER

RESET

IN 2

COM

SEN 1

0-10V+

0-10V-

Lockout

Fan In

Heat Hi In

Heat Hi Out

Heat Lo In

Heat Lo Out

E L

Fan Out

L Out

SUPPLY IN Mod Out

Remote Sensor

(optional)

T1 3 T2 1

NEUTRAL

LIVE

EARTH

NVx HEATER (Modulating)

L N E

2 3 4 5 6

Note: MC200

internal sensor

is removed

Note: MC200

internal sensor

is removed

Page 22

Note: The NVx Heater, Powrtrol, time clock or room thermostat may be fed by separate electrical supplies providing both supplies are the same phase.

Warning: If external controls are not isolated 230V may be present at heater terminals even when the heater is isolated.

ON/OFF NVx

TIME SWITCH

ROOM

STAT

Lockout Indicator

Push Button Reset

L/O

R/S

230V

out

ROOM

STAT

Lockout Indicator

Push Button Reset

L/O

R/S

230V

out

NEUTRAL

LIVE

EARTH

NVx HEATER (ON/OFF)

L N E

NEUTRAL

LIVE

EARTH

NVx HEATER (ON/OFF)

L N E

NEUTRAL

LIVE

EARTH

NVx HEATER (ON/OFF)

L N E

2 3 4 5 6

Page 23

9. Fault Finding Flow Chart

Note: APS = Air Pressure Switch

Check Fuse ‘L’

Gas & Electrical supplies present at heater?

Turn supplies on, Check fuses/connections

230V Between 1 & 2 on Brahma control?

Limit thermostat tripped (red lamp on front panel on)?

Check fuse on Brahma control

Press red reset button on fan/limit thermostat (in controls section)

Yes

Unit at lockout (lockout lamp on low level controls

and on internal control panel alight)?

Check for 230V at upper terminal on

limit side of fan/limit thermostat

Yes

Replace (3.15A), ascertain cause of failure and rectify

Replace (4A), ascertain cause and rectify

Failed

Check for faulty connection. Replace as necessary.

Yes

START

Yes

Check APS sensing tube. Check negative pressure developed by exhaust fan. Adjust APS set point. Change APS

Yes

Ignition sparks?

Check/replace ignition probe/lead. Faulty Brahma control box

Yes

Burners light?

Check ignition electrode position. Is gas pipe work purged of air? Check gas pressures. Replace gas valve

Check rectication probe/lead. Faulty Brahma Control

4 more ignition attempts then lock out.

Exhaust fan continues to run APS has lost C. to N.O. continuity, slightly reduce APS set point.

Check for 230V between terminals 7 & 15 of the terminal strip

Absent

Replace motor, capacitor or fan/motor assembly

Check connections, overloads etc as applicable

Absent

Finish

Burners remain alight?

Check for 230V between terminals 12 & 11 of the terminal strip

Check connections, Faulty Brahma Control

Yes

230V at APS Terminal C ?

Present

230V at APS Terminal N.O ?

Check for 230V between terminals 13 & 14 of the terminal strip

Check connections, Faulty Brahma Control

Faulty Gas Valve

Yes

Main fan runs?

Main fan running - wait for unit temperature to reduce - push red thermostat reset button. If it will not reset when cold - change thermostat

Check for 230V at terminal 1 of terminal strip

Absent

External control circuit not calling for heat

Press lockout reset button on low level controls or on internal control panel

Continuity between APS C and NO connections - check for reason, adjust APS setting or change APS. Faulty Brahma control or connections.

Check connections, Faulty exhaust fan and/or capacitor

Yes

Exhaust fan runs?

Yes

Gas valve opens?

Depending on fan /motor type - Check for 230V at the main fan motor

Check connections. Fan/limit thermostat faulty - check/replace

Present

Page 24

ITEM USAGE PART #

MFC 10-90 145035204

MFC 120/140 141378715

Ignition Electrode 10-75 142423002 Ignition Electrode 90-140 142423004

Rectification Electrode All 142423003

Burner 10-75 142400240 Burner 90-140 142400241

Fan & Limit Thermostat All 143000303

Control Box All 145030844

Hi/Lo Governor Head 10-140 -/HL 142466402

Modulating Governor Head 10-140 -/MOD 142466403

Modulating Driver 10-140 -/MOD 142400305

Exhaust Fan 10-50 140210496 As an assembly c/w mounting brackets 10-50 NVX1050EXH

Exhaust Fan 60/75 140201505 As an assembly c/w mounting brackets 60/75 NVX6075EXH

Exhaust Fan 90-140 140201506 As an assembly c/w mounting brackets 90-140 NVX90140EXH

Pressure Switch All 146522174

Contactor 120-140, All -/C 143000600 Contactor 60-90, All -/C 143000601

10. Short List of Parts

Only originally specied parts may be tted as service replacements and all items are available from the Powrmatic Ltd Spares Department. Please refer to Powrmatic Ltd for any parts not shown in the listing. Powrmatic Ltd must also be consulted before parts other than those specied or recommended in the servicing instructions are replaced.

Page 25

Every effort is made to ensure accuracy at time of going to press. However as part of our policy of continual product improvement, we reserve the right to alter specifications without prior notice.

HEATING DIVISION

Hort Bridge

Ilminster, Somerset TA19 9PS

Tel: 01460 53535 Fax: 01460 52341

BSI Registered Firm

FM 414

Ind. & Comm. Air Heaters;

Air Moving Equipment;

Flues & Chimneys; Natural

Smoke & Heat Ventilators; Powered Supply & Extract

Fans & Systems.

ISO 9001

ITEM USAGE PART #

Main Air Fan - Axial 10 140232001 Main Air Fan - Axial 15 140232002 Main Air Fan - Axial 20 140232003 Main Air Fan - Axial 25/30 140232004 Main Air Fan - Axial 35/40 140232005 Main Air Fan - Axial 50/90 140232006 Main Air Fan - Axial 60/75/120/140 140232007