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MF47-3.05 

 

18 

8.0

 

F

USES 

&

 

P

OWER 

C

ONTROL

 

8.1

 

Fuses 

F1-F2: Refer to the circuit diagrams. 

F1

 

 

Internal supply 
fuses 

Fitted if a supply cable originally 
fitted. 

Ferraz fuse of the rating shown 

F2

 

 

Auxiliary 
circuit fuses 

 

2 Amps type F 
32mm x 6mm  

F4

 

Thyristor Fuse 

 

Ferraz Protistor fuse of the rating 
shown 

 

Customer 
fuses 

Required if no supply cable fitted. 
Recommended if cable fitted. 

See rating label for amperage; see 
table below for fuse rating. 

 

The table below gives the fuse rating for the various models. 

8.2

 

Power Control 

The setting for the power limit parameter in the controller (

OP.Hi

) should be 100% for all models. 

The current-limiting thyristor stacks are set to the maximum element currents given in the table. 

 

TABLE OF FUSE AND CURRENT LIMIT VALUES 

Model 

Phases 

volts 

supply fuse 
rating 

 

thyristor 
fuse 
rating 

current 
limit 
(element 

circuit) † 

HTF 17/5 

1-phase 

208 

20A 

30A 

150A 

HTF 17/5 

1-phase 

220-240 

20A 

30A 

150A 

 

 

 

 

 

 

HTF 17/10 

1-phase 

208 

30A or 32A 

50A 

150A 

HTF 17/10 

1-phase 

220-240 

30A or 32A 

50A 

150A 

HTF 17/10 

2-phase * 

380-415 

20A 

30A 

150A 

 

 

 

 

 

 

HTF 18/4 

1-phase 

208 

20A 

30A 

140A 

HTF 18/4 

1-phase 

220-240 

25A 

30A 

140A 

 

 

 

 

 

 

HTF 18/8 

1-phase 

208 

32A 

50A 

140A 

HTF 18/8 

1-phase 

220-240 

30A 

50A 

140A 

HTF 18/8 

2-phase * 

380-415 

16A 

30A 

140A 

 

 

 

 

 

 

* 2-phase designs use the line-to-line voltage; neutral is used for the control circuit 

† see section 4.6 – the current limit setting at low temperatures is 146A 

Summary of Contents for Carbolite HTF 17

Page 1: ...is connected to the electricity supply Manuals for the furnace controller and overtemperature controller are supplied separately Please read the controller manuals before operating the furnace Contents Section Page 1 0 Introduction 2 2 0 Installation 3 3 0 Operation 5 4 0 Maintenance 8 5 0 Repairs Replacements Adjustments 10 6 0 Fault Analysis 15 7 0 Circuit Diagram 16 8 0 Fuses Power Control 18 9...

Page 2: ...an or by someone with a thorough understanding of electrical components and safety Operating should be done by a person who has read this manual and is aware of and understands the safety issues in using high temperature electrically heated equipment Heat Light the adjacent light glows or flashes to indicate that power is being supplied to the elements DANGER of electrical shock read any warning p...

Page 3: ...free space around the furnace and preferably 1 5m above Do not obstruct any of the vents in the case or leave objects of any kind on the top surface In particular the cooling fans in the case must not be obstructed If the furnace is to be used in a process which could liberate hazardous gases then it should be installed together with a suitable fume extraction system A direct connection to the fur...

Page 4: ...nnecting device for the furnace The supply MUST incorporate an earth ground CONNECTION DETAILS supply type Supply Terminal label Cable colour Live Neutral Reversible or Live Live 1 phase L Brown to live to either power conductor N Blue to neutral to the other power conductor PE Green Yellow to earth ground to earth ground 2 phase L1 Black to phase 1 L2 Black to phase 2 N Light Blue to neutral PE G...

Page 5: ...oling fans are still running if the furnace is above that temperature If the furnace is to be left off unattended and has cooled down isolate it from the electrical supply 3 2 Operator Safety Electrical The furnace incorporates a safety switch which interrupts the heating element circuit when the door is opened This prevents the user touching a live heating element but also prevents the furnace fr...

Page 6: ...gen argon or helium atmospheres to 1600 C Reducing atmospheres are not recommended Sulphur dioxide in normal concentrations is not harmful but chlorine and more so fluorine strongly attack even oxidised elements and should be avoided The furnace is not recommended for burning off carbonaceous materials Other Carbolite furnaces are available for this application When an optional gas inlet is fitted...

Page 7: ...uples low temperatures The thermocouples fitted to these models give very low outputs below about 600 C and do not give accurate readings at low temperatures They may show a negative temperature when the furnace is started from cold The furnaces are designed for operation over 800 C they may be run below this temperature but accurate temperature measurement and stability is not assured 3 13 Therma...

Page 8: ...cked from time to time If the glaze has gone it may be restored by heating the furnace up to 1500 C without load for 2 hours or so 4 2 Calibration After prolonged use the controller and or thermocouple could require recalibration see the warning about 1700 1800 C thermocouples in section 3 11 This would be important for processes which require accurate temperature readings or which use the furnace...

Page 9: ...s case the power limit is accessible to the operator and may be reset to its standard value of 100 4 6 Power Adjustment Thyristor The current limiting thyristor stacks which control power to the elements are fitted with an adjustable resistor which is factory set to limit the maximum current supplied In the event of a change of supply voltage or the fitting of a new thyristor re adjustment is requ...

Page 10: ...ion Wool industry www ecfia eu We can provide further information on request Alternatively our service division can quote for any repairs to be carried out at your premises or ours 5 3 Side Panel Removal Except where explicitly stated always disconnect the electrical supply before removing the side panel Remove the panel by slackening the four fixing screws behind plastic caps at the left hand end...

Page 11: ...back panel 1700 models or top cover 1800 models Make a note of the thermocouple connections The negative leg of the thermocouple is marked blue The compensating cable for 1700 1800 C thermocouples is plain copper Disconnect the thermocouple from its terminal block Undo the screw to release the thermocouple sheath withdraw the sheath and shake out any fragments of thermocouple Re assemble with a ne...

Page 12: ...n above on initial installation Remove the aluminium braids and clips using the clip tool provided with the furnace Lift out the old elements and the insulation blocks handle the insulation pieces with care as they are fragile Carefully loosed and remove the clamps Prepare and install the new elements as explained above Heat up the furnace to a moderate temperature and ensure that the furnace is c...

Page 13: ...MF47 3 05 13 Element Connections 4 Elements Element Connections 5 Elements Terminal Block Element Braid Terminal Block Element Braid ...

Page 14: ...lternatively be L1 and L2 for a live to live supply The L side should be connected to the correct tapping to match the supply voltage The link wire should be in position as shown unless the supply voltage is always low in which case there is the option of moving one end to the 2 terminal Important Changing the transformer primary tapping including the 2 requires adjustment of the thyristor current...

Page 15: ...as activated There are no lights glowing on the controller Check the supply fuses and any fuses in the furnace control compartment The controller may be faulty or not receiving a supply due to a faulty switch or a wiring fault B Furnace Overheats 1 The HEAT light goes OFF with the instrument switch The controller shows a very high temperature The controller is faulty The controller shows a low tem...

Page 16: ...pply fuses present if supply cable fitted F2 Auxiliary circuit fuses 2A F4 Thyristor protection fuse Ferraz Protistor BU Blue R Red P Pink G Grey GR Y Green Yellow Coil N Elements Contactor BU R Thyr istor BU R OTC P G TC Control thermocouple O temp thermocouple Door Switch Element Transformer Heat Light Case Cooling Fans F2 F1 GR Y PE L EMC Filter F4 Thermal Cutouts Fault Light Instrument Switch ...

Page 17: ...f supply cable fitted F2 Auxiliary circuit fuses 2A F4 Thyristor protection fuse Ferraz Protistor BL Black BU Blue P Pink G Grey GR Y Green Yellow Coil L2 Elements Contactor BU BL Thyr istor BL BU OTC P G TC Control thermocouple O temp thermocouple Door Switch Element Transformer Case Cooling Fans F2 F1 GR Y PE L1 EMC Filters F4 Thermal Cutouts N F1 Fault Light BL 94KΩ Heat Light Instrument Switch...

Page 18: ...ld be 100 for all models The current limiting thyristor stacks are set to the maximum element currents given in the table TABLE OF FUSE AND CURRENT LIMIT VALUES Model Phases volts supply fuse rating thyristor fuse rating current limit element circuit HTF 17 5 1 phase 208 20A 30A 150A HTF 17 5 1 phase 220 240 20A 30A 150A HTF 17 10 1 phase 208 30A or 32A 50A 150A HTF 17 10 1 phase 220 240 30A or 32...

Page 19: ... 5 106 HTF 18 4 1800 C 4 6 141 140 205 4 2 92 HTF 18 8 1800 C 6 2 210 190 205 8 2 4 113 Maximum power as measured included ancillary components and transformer losses 9 2 Environment The furnaces contain electrical parts and should be stored and used in indoor conditions as follows temperature 5 C 40 C relative humidity maximum 80 up to 31 C decreasing linearly to 50 at 40 C altitude not exceeding...

Page 20: ...es manufactured by Carbolite for laboratory and industrial use For further details of our standard or custom built products please contact us at the address below or ask your nearest stockist Copyright 2014 Carbolite Limited For preventive maintenance repair and calibration of all Furnace and Oven products please contact Carbolite Engineering Services Telephone 44 0 1433 624242 Fax 44 0 1433 62424...

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