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1700-1800° Chamber 
 

 

F

AULT 

A

NALYSIS

 

 

A.

 

Furnace Does Not Heat Up

 

 

 

 

   

1. 

The 

HEAT

 light 

 is 

ON

 

Æ

  An ohm meter applied to 

the element circuit shows 
an open circuit 

Æ

A heating element has failed 

 

2. 

The 

HEAT

 light  

is 

OFF

 

 

The controller shows 

very high temperature

 

or a code such as S.br 

Æ

The thermocouple has broken 
or has a wiring fault 

 

 

 

The controller shows a

 

low temperature

 

Æ

The door switch may be faulty 
or need adjustment 

 

 

 

 

Æ

The thyristor fuse may have 
blown 

 

 

 

 

Æ

The power thyristor could be 
failing to switch on due to 
internal failure, faulty wiring 
from the controller, or faulty 
controller 

 

 

 

There are no 
lights glowing 
on the 
controller 

Æ

The 

SUPPLY

 light is 

ON

 

Æ

  The controller may 

be faulty or not 
receiving a supply 
due to a faulty switch 
or a wiring fault 

 

 

 

 

Æ

The 

SUPPLY

 light is 

OFF

 

Æ

  Check the supply 

fuses and any fuses in 
the furnace control 
compartment 

B.

 

Furnace Overheats

 

 

 

 

   

1. 

The 

HEAT

 light 

goes 

OFF

 with the 

instrument switch 

Æ

  The controller shows a 

very high temperature

 

Æ

The controller is faulty 

 

 

Æ

  The controller shows a 

low temperature

 

Æ

The thermocouple may have 
been shorted out or may have 
been moved out of the furnace 

 

 

 

 

Æ

The thermocouple may be 
mounted the wrong way round 

 

 

 

 

Æ

The controller may be faulty 

2. 

The 

HEAT

 light 

does not go off

 with 

the instrument 
switch and the fault 
persists when a 2A 
control fuse is 
removed from its 
fuse-holder 

Æ

  The power thyristor has 

failed “ON” 

Æ

Check for an accidental wiring 
fault which could have 
overloaded the thyristor. 

Isolate the furnace if this fault 
persists.

 

 

 

7.0 

12 

MF22 

Содержание HTF 18/15

Страница 1: ...nnected to the electricity supply CONTENTS Section page 1 0 Symbols Warnings 2 2 0 Installation 3 3 0 Operation 5 4 0 Maintenance 8 5 0 Repairs Replacements 8 6 0 Fault Analysis 12 7 0 Circuit Diagram...

Страница 2: ...glows Heat Light the adjacent light glows or flashes to indicate that power is being supplied to the elements 1 2 Warning Symbols DANGER of electrical shock read any warning printed by this symbol DA...

Страница 3: ...there is free space around the furnace Do not obstruct any of the vents in the case there are cooling fans in the case which must not be obstructed Ensure that the furnace is placed in such a way that...

Страница 4: ...nual In some models supply cables are fitted as are internal supply rated fuses The cable may be directly wired to an isolator or fitted with a line plug The supply point must be within reach of the f...

Страница 5: ...d Find and correct the cause before resetting the overtemperature controller according to the instructions supplied To switch the furnace off set the Instrument switch to off The case cooling fans rem...

Страница 6: ...hearth can be protected from abrasion if required by the provision of a secondary plate This consumable item can either be in light weight ceramic fibre or in dense hard wearing alumina refractory 3...

Страница 7: ...by a calibration test or by comparing the output with a new reference thermocouple which has been subjected to high temperatures for a minimum length of time Failure to check the thermocouple may res...

Страница 8: ...ont of this booklet when supplied with a furnace To contact Thermal Engineering Services or Carbolite see the back page of this manual 4 4 Recommended Spares Kits Carbolite can supply individual spare...

Страница 9: ...rately Before commencing any major repairs we recommend reference to the European Ceramic Fibre Industry Association Bulletin No 11 and the UK Health and Safety Executive Guidance Note EH46 We can pro...

Страница 10: ...ponents and the support system appropriate to your furnace There are also variations in the positions of the braids which connect the elements the rule is that for single phase all elements are in ser...

Страница 11: ...ler clips do no require clip tool Element Data distance from top of element clamp to top of element RHF 17 3 RHF 17 10 32mm RHF 17 25 HTF 18 3 47mm HTC 18 8 45mm HTF 18 15 40mm HTF 18 27 40mm Element...

Страница 12: ...controller may be faulty or not receiving a supply due to a faulty switch or a wiring fault The SUPPLY light is OFF Check the supply fuses and any fuses in the furnace control compartment B Furnace O...

Страница 13: ...ansformer may be fitted 2 Door actuator circuits may differ from the example shown 7 2 Three Phase Models Each set pair of elements has its own transformer controlled by a thyristor complete with thyr...

Страница 14: ...1700 1800 Chamber 14 MF22...

Страница 15: ...troller OP Hi should be 100 for all models The thyristor stacks are set to the secondary element maximum currents given in the table TABLE OF FUSE AND CURRENT LIMIT VALUES Model Phases volts supply fu...

Страница 16: ...g the details below UK Office Keison Products P O Box 2124 Chelmsford Essex CM1 3UP England Tel 44 0 330 088 0560 Fax 44 0 1245 808399 Email sales keison co uk Please note Product designs and specific...

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