VERDER Carbolite TZF Series, TZF 12/75/700, TZF 12/38/400, TZF 12/65/550, TZF 12/100/900 Installation, Operation & Maintenance Instructions Manual

CONTENTS

Section page

Installation, Operation &

Maintenance Instructions

1200°C Tube furnaces (3-zone)

types TZF

This manual is for the guidance of operators of the above Carbolite products

and should be read before the furnace is connected to the electricity supply.

Manuals are supplied separately for the furnace controllers

(and overtemperature controller when fitted).

Please read the controller manuals before operating the furnace.

1.0 INTRODUCTION

Instrument switch: when the instrument switch is operated the temperature
control circuit is energised.

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 printed by this symbol.

DANGER – hot surface. Read any warning printed by this symbol.
WARNING: all surfaces of a furnace may be hot.

DANGER – read any warning printed by this symbol.

Heat Switch: the switch disconnects power to the heating elements; unless
this switch is off there is a danger of electric shock when inserting objects
into the furnace

1.1 Switches and Lights

1.2 Warning Symbols

2 MF12 3.12

2.0 INSTALLATION

2.1 Unpacking & Handling

When unpacking or moving the furnace always lift it by its base or by both ends of the main body.

Never lift it by its work tube or the surrounding insulation. For the larger models, or where the
furnace and control box are not fixed together, use two people to carry the furnace.

Remove any packing material from inside the furnace before use.

NOTE: This product contains Refractory Ceramic Fibre (better described as Alumino Silicate
Wool) for precautions and advice in handling this material see the ‘Repairs and Replacements’
section.

2.2 Siting

Place the furnace in a well ventilated room, away from other sources of heat, and on a surface

which is resistant to accidental spillage of hot materials. Do not mount the furnace on an
inflammable surface.

Ensure that there is free space around the furnace. Do not obstruct any of the vents in the control

section: they are needed to keep the controls cool.

Ensure that the furnace is placed in such a way that it can be quickly switched off or disconnected

from the electrical supply - see below.

2.3 Setting Up

A furnace ordered for vertical use has a small clip or plate at one end to prevent a wound tube

element or a work tube from slipping downwards. Mount the furnace so that this clip is at the
bottom. In models with one thermocouple the thermocouple should be near the top rather than the

bottom.
If the furnace is supplied with a separate work tube or any accessories fit these into position.
For optimum temperature uniformity, insulating plugs should be placed in the tube ends as shown

in fig.1. With a long work tube, the stem of the plug assembly should line up with the end of the

tube as in fig.2. Alignment of radiation shields is similar to that of plugs.
If stainless steel seals with gas inlets are supplied they are to be fitted as shown in fig.3; the stem

of any insulating plug should touch the seal. Stainless steel seals for vertical use: a hook and eye

arrangement holds the upper insulating plug assembly; alternatively a gland nut.
Horizontal models: if heavy fittings are to be clamped to the end of an extended work tube they

can increase the bending stress at the centre of the tube. Support such fittings in such a way that

expansion of the tube is allowed.
If a metal work tube is being used in the furnace, ensure that it is earthed. In the case of wound-

tube models (TZF) it should be mounted so as not to touch the furnace ceramic tube. See the safety

warning in section 3.4.

MF12 3.12 3

2.4 Electrical Connections

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)

supply

Terminal label

Cable colour

2- or 3-phase

L1

Black

to phase 1

L2

Black

to phase 2

L3

Black

to phase 3 except 2-phase

N

Light Blue

to neutral except delta

PE

Green/Yellow

to earth (ground)

Connection by a qualified electrician is recommended.

The furnaces covered by this manual may be ordered for single phase A.C. supply, which may be

Live to Neutral non-reversible, Live to Neutral reversible or Live to Live. Some models can be

supplied for three phase use; some for use on two phases of a three phase with neutral supply (one

phase unused).
Check the furnace rating label before connection. The supply voltage should agree with the voltage

on the label, and the supply capacity should be sufficient for the amperage on the label.
The supply should be fused at the next size equal to or higher than the amperage on the label. A

table of the most common fuse ratings is also given in section 8.1 of this manual. Where a supply

cable is present there are internal supply fuses; customer fusing is preferred but not essential.
Furnace with supply cable: either wire directly to an isolator or fit with a line plug.
Furnace without supply cable: a permanent connection to a fused and isolated supply should be

made to the internal terminals after temporary removal of the furnace back panel.
Connection by line plug: the plug should be within reach of the operator, and should be quickly

removable.
Connection to isolating switch: this should operate on both conductors (single phase) or on all live

conductors (three phase), and should be within reach of the operator.
The supply MUST incorporate an earth (ground).

4 MF12 3.12

3.0 OPERATION

Home

List

Access

List

°C/F/k

ACCS

°C/F/k

codE

0.0

Zone temperature
difference; use /
to access offset

home list

for factory access to lists
and parameters not
available to the operator



OP.Hi

Output

oP

power limit
setting, if
present

The instructions for operating the temperature controller are given in a separate manual.
If the furnace is fitted with a time switch, see also the supplementary manual MS03.
If cascade control is fitted, see the supplementary manual MS07.

3.1 3-zone Control Methods

The models in this manual are typically designed to achieve an extended uniform temperature zone

by the use of three control zones. The control zones are typically linked so that they are all follow

the central controller in a master-slave approach; there are two ways of doing this. Alternatively

independent control zones may be ordered. There are thus three control methods (A, B & C).

A. Back-to-Back Thermocouples

This is the most commonly supplied option.
The central zone of the work tube is controlled directly by the central temperature controller. Each

end zone thermocouple is wired in opposition to a central reference thermocouple, and the small

voltage resulting when the zones are at different temperatures is used by the end zone controller.

The circuit diagram in section 7.1 shown the thermocouple arrangement.
Set the "setpoint" of the end zone controllers to zero. Alternatively, a small temperature difference

(offset) can be created by setting a non-zero value, but the sum of the main controller set-point and

the slave controller offset MUST NOT exceed the furnace maximum temperature. The "measured

temperature" display shows the actual offset.
To alter the setpoint (with the display at “home”), press Down  or Up  once to display the

setpoint; press again or hold down to adjust it. The display returns to the measured temperature

offset when no key is pressed for 0.5 seconds.
Sometimes a furnace using this type of control does not cool down: the end controllers try to

remain at the central temperature. Should this occur, contact Carbolite’s technical department.
2132 Slave Controller Navigation Diagram

B. Retransmission of Setpoint using Broadcast comms

When this is ordered there are three independent thermocouples connected to the three

controllers. The controllers are linked together, the central controller communicating the desired

setpoint to the end controllers.

Additional communication modules are fitted in the controllers, rather than an additional

thermocouple as in A. The communication between the controllers of the Eurotherm 3000 series is

known as Broadcast comms.

It is possible to switch off the linked control and allow the controllers to work independently. In

level 2 of the end zone controllers (see controller operating instruction), scroll to L-r. Where the

end zone controller is a 3216 use the  up  down and select NO. Where the end zone controller

is a 3508 use the  up  down to select SP1, (SP1 = Local, and SP2 = Remote). There is no

need to alter the centre controller.

It is possible to use local trim in the end zone controllers to enter a positive or negative adjustment

from the centre zone temperature. Once entered this trim will always be added or subtracted from

MF12 3.12 5

the retransmitted set temperature. In level 2 of the end zone controller (see controller operating

instruction), scroll to LOC.T (local trim) and use the  up  down enter the desired positive or

negative difference to be added to the end zone set temperature. There is no need to alter the

centre controller.

C. Independent Control

In this case the three controllers are completely independent. Note that it is not possible to

maintain very different zone temperatures because of heat transfer within the work tube.

3.2 Operating Cycle

The furnace is fitted with an instrument switch. The switch cuts off power to the controller(s) and

contactor (when fitted). There is also a heater switch which can be used to disconnect power to the

elements.
Connect the furnace to the electrical supply.
Operate the instrument switch to activate the temperature controller. The controller becomes

illuminated and goes through a short test cycle.
Control methods A & B: Set the slave (end zone) controllers to the desired offset temperature,

usually zero. Set the main (central) temperature controller to the desired setpoint or program. See

section 3.1 and/or the separate manual(s) for the controller(s).
Control method C: Set the three controllers to the desired temperatures. See the separate

manual(s) for the controller(s).
Overtemperature option only. If the overtemperature controller has not yet been set as required, set

it and activate it according to the instructions in the appropriate manual.
Switch on the Heater switch, located on the instrument panel. Unless a time switch is fitted and is

off, the furnace starts to heat up. The Heat light(s) glow steadily at first and then flash as the

furnace approaches the desired temperature or a program setpoint.
Overtemperature option only. If the overtemperature trip operates then an indicator in the over-

temperature controller flashes, and the heating elements are isolated. Find and correct the cause

before resetting the overtemperature controller according the instructions supplied.
To switch off power to the heating elements, use the Heater Switch. To switch the furnace off, use

both the Heater switch and the Instrument switch. If the furnace is to be left off unattended, isolate

it from the electrical supply.

3.3 General Operating Advice

Heating element life is shortened by use at temperatures close to maximum. Do not leave the

furnace at high temperature when not required. The maximum temperature is shown on the furnace

rating label and on the back page of this manual.
Lightweight ceramic fibre insulation can easily be marked by accidental contact. Some fine cracks

may be visible on the surface of the insulation, or may develop in the surface of the chamber due

to the progressive shrinkage of the insulation materials. Cracks are not usually detrimental to the

functioning or the safety of the furnace.

3.4 Operator Safety

The ceramic materials used in furnace manufacture become electrically conductive to some extent

at high temperatures. DO NOT use any conductive tools within the work tube without isolating it.

If a metal work tube is used, it must be earthed (grounded).
Switch off the Heater switch whenever loading or unloading the furnace. The elements are isolated

when the Heater switch is OFF. This switch cuts both sides of the circuit directly or via a contactor

(a contactor is used in models where the rated current exceeds 16 Amps).

6 MF12 3.12

3.5 Tube Life

A ceramic work tube may be cracked if workpieces are inserted

too quickly or at temperatures below 900°C (when the tube is

more brittle). Large pieces should also be heated slowly to

ensure that large temperature differences do not arise.
Poor thermal contact should be encouraged between the

workpiece and the tube; crucibles or boats should be of low

thermal mass and should have feet to reduce the contact with

the tube (fig. 4).
Do not set too high a heating rate. Large diameter tubes are more susceptible to thermal shock than

smaller. Tubes which extend beyond the heated part of the furnace are more at risk. A general rule

for maximum heating rate is 400/internal diameter (°C/min); for 75mm i/d tubes this comes to 5°C

per minute. The controller can be set to limit the heating rate.

3.6 Pressure

Work tubes are not able to accept high internal pressure. When gas seals or similar fittings are in

use, the gas pressure should be restricted to a maximum of 0.2 bar (3 psi). A pressure of about half

of that should normally be sufficient to achieve the desired flow rate. The customer must ensure

that the exhaust path from the tube is not blocked, so that excess pressure does not occur.

3.7 Power Adjustment

The furnace control system incorporates electronic power limiting. The power limit parameter

OP.Hi is accessible to the operator, and can be used to adjust the furnace to the actual supply

voltage.
Note that any power limit applies to all three controllers.
Some models covered by this manual are are fitted with 208V elements and are designed for use

over the range of voltages 200V-250; the power limit parameter is set accordingly. These models

may be relocated to a different voltage within the range: the power limit should be reset to match

the voltage. See section 8.2.

To check whether the furnace is a 208V model:

- look at the OP.Hi parameter – make a note of the value and compare with section 8.2;

- observe the rating label; if a range of voltages is stated, it is not a 208V multivoltage model;

- if in doubt, check with Carbolite – each product has its own record card.

To alter the power limit
Set the Heater Switch to Off to prevent heating while adjusting the power limit.
Press Page  until oP (output list) is displayed. Press Scroll  until OP.Hi (Output High) is

displayed. Press Down  or Up  once to display the value of OP.Hi (it is good practice to write

down the original value). To alter the parameter to the desired value use Down  or Up .
A power setting of zero prevents the furnace from heating: useful for demonstrating the controls

without taking power.
Do not increase the power limit simply “to get more power”. The elements could burn out, or a

fuse could blow.

3.8 Running at Low Temperatures

The power limit may be adjusted to a low level to achieve better control when running the furnace

at a low temperature. No hard and fast rules can be given, but, as an example, to run at

temperatures only up to 600°C try a power limit of 50%. Control stability may fall off again if a

setting below about 40% is used. Before changing the power limit, record its factory setting

for possible future use.

MF12 3.12 7

4.0 Maintenance

4.1 General Maintenance

No routine maintenance is required. The outer surfaces may be cleaned with a damp cloth. Do not

allow water to enter the interior of the case, tube or control box. Do not clean with organic

solvents.

4.2 Calibration

After prolonged use the controller and/or thermocouple could require recalibration. This would be

important for processes which require accurate temperature readings or which use the furnace

close to its maximum temperature. A quick check using an independent thermocouple and

temperature indicator should be made from time to time to determine whether full calibration is

required. These items can be supplied by Carbolite.
Depending on the controller, the controller manual may contain calibration instructions.

4.3 After Sales Service

Carbolite’s service division (Carbolite Engineering Services) has a team of Service Engineers

capable of repair, calibration and preventive maintenance of furnace and oven products at our

customers’ premises throughout the world. We also sell spares by mail order. A telephone call or

fax often enables a fault to be diagnosed and the necessary spare part despatched.
Each furnace has its own record card at Carbolite. In all correspondence please quote the serial

number, model type and voltage given on the rating label of the furnace. The serial number and

model type are also given on the front of this booklet when supplied with a furnace.
To contact Carbolite Engineering Services or Carbolite see the back page of this manual.

4.4 Recommended Spares Kits

Carbolite can supply individual spares, or a kit of the items most likely to be required. Ordering a

kit in advance can save time in the event of a breakdown. Each kit comprises one of each type of

thermocouple, one solid state relay, and one heating element
When ordering spares please quote the model details as requested above.

8 MF12 3.12

5.0 REPAIRS & REPLACEMENTS

5.1 Safety Warning – Disconnection from Supply

Always ensure that the furnace is disconnected from the supply before repair work is

carried out.

5.2 Safety Warning - Refractory Fibrous Insulation
Insulation made from High Temperature Insulation Wool

Refractory Ceramic Fibre, (better described as Alumino Silicate Wool) (ASW)

This product contains alumino silicate wool products in its thermal insulation. These materials

may be in the form of blanket or felt, formed board or shapes, mineral wool slab or loose fill wool.

Whilst there is no evidence of any long term health hazards, we strongly recommend that safety

precautions are taken whenever the materials are handled.

Exposure to fibrous dust may cause respiratory disease.

When handling the material always use an approved respiratory protection equipment

(RPE-i.e. FFP3), eye protection, gloves and long sleeved clothing.

Avoid breaking up waste material. Dispose of waste in sealed containers.

After handling rinse exposed skin with water before washing gently with soap (not

detergent). Wash work clothing separately.

Before commencing any major repairs we recommend reference to the European Association

representing the High Temperature Insulation 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 Temperature Controller Replacement

201. This controller is fitted to the back of the control panel; in many models this can be separated

from the base by removal of two screws.
Before handling the controller: wear an anti-static wrist strap or otherwise avoid any possibility

of damage to the unit by static electricity.
Refer to the detailed instructions supplied with the replacement controller.
2000 & 3000 series. Ease apart the two lugs at the side; grip the instrument and withdraw it from

its sleeve; push in the replacement.

5.4 Solid-state Relay Replacement

Disconnect the furnace from the supply and remove the back panel from the base or control box..
Make a note of how the wires are connected to the solid state relay, and disconnect them.
Remove the solid state relay from the base panel or aluminium plate.
Replace and reconnect the solid state relay ensuring that the heat-conducting thermal pad is

sandwiched between the relay and the base panel or aluminium plate. Alternatively a thin layer of

white, heat-conducting silicon paste may be applied between the new relay and the plate.
Replace the removed panel.

MF12 3.12 9

5.5 Thermocouple Replacement

current models

negative: white

positive (type K): green

positive (type N): pink

old models

negative: blue

positive (type K): white

positive (type N): orange

The coverings and guards which must be removed to gain access to the thermocouple depend on

the model, its orientation (horizontal or vertical), and possibly other options and fittings. It is

usually necessary to separate the furnace from its base or stand. On horizontal models (except TZF

12/38) one outer end-cap should be removed; on TZF 12/38 and vertical models the terminal

cover.
Disconnect the furnace from the supply, and separate the furnace body and/or remove covers and

guards as necessary.
Make a note of the thermocouple connections. Type N colour codings are:

Disconnect the thermocouple from its terminal blocks.
Withdraw the thermocouple from its sheath and remove any broken bits of thermocouple.
Bend the new thermocouple carefully to match the shape of the original (working from the

terminal end). Should the length differ from that of the original this is usually not important

provided that the thermocouple tip is within a tube diameter's distance from the furnace centre.
Insert the new thermocouple into position, restoring any removed porcelain spacers, and ensuring

correct polarity.
Re-assemble the furnace.

5.6 Element Replacement

Please see safety note 5.2 - please wear a face mask.

The coverings and guards which must be removed to enable replacement of the wound tube

element depend on the furnace model, its orientation (horizontal or vertical), and other options and

fittings. The general procedure is:
Disconnect the furnace from the electrical supply.
Remove all outer guards, meshes and terminal covers from the furnace body. For a horizontally

mounted furnace remove the furnace body from its base; to reach the bolts or screws which fix the

body to the base, remove the back panel from the base.
Disconnect all electrical leads from the terminal blocks on the furnace case. Note the colours and

positions of the connecting leads to enable correct reassembly. Take care not to crack porcelain

terminal blocks - use two spanners where appropriate.
Remove the thermocouples.
Lay the furnace body horizontally with the split in the cylindrical case uppermost. Remove the two

metal end-caps from the body. Except TZF 12/38, undo the self-tapping screws which hold the

terminal strip to the case join. The case should spring open slightly. Remove the ceramic board

disc from one end.
Use a sharp knife to cut right through the insulation down to the wire-wound tube element along

the whole length of the body, but do not cut either of the ceramic board end discs. The knife cut

must be in line with the element lead wires. Slide the element gently out through the end of the

furnace body.
Check the cylindrical case and clean out as appropriate.
Remove any insulation sleeving from the tails of the old element and fit to the replacement

element.
Slide in the new element(s). Close up the furnace again, refitting the terminal strip (where

applicable) and the end-caps. Any cut made in the insulation should close up completely: if the

insulation appears loose or damaged in any way, please contact our service division.

10 MF12 3.12

Reverse the rest of the disassembly process. Take care to make all connections to the correct

terminals. Do not overtighten the connectors in porcelain terminal blocks.
Let the furnace heat up at its maximum rate to 900°C without interruption, and then soak for 1

hour. Fumes may be emitted: this should be done in conditions of good ventilation.
Check that the furnace is controlling properly to rule out the possibility that the element failed

because of a fault in the control system.
If you have any problems with this procedure, please contact our service division.

5.7 Fuse Replacement

Fuses are marked on the circuit diagram (section 7.1) with type codes, e.g. F1, F2. A list of the

correct fuses is given in section 8.1. Depending on model and voltage, the different fuse types may

or may not be fitted.
If any fuse has failed, it is advisable for an electrician to check the internal circuits.
Replace any failed fuses with the correct type. For safety reasons do not fit larger capacity fuses

without first consulting Carbolite.
The fuses are near the cable entry point, and access is by removal of the back panel of the base or

control box.

MF12 3.12 11

6.0 FAULT ANALYSIS

A.

Furnace Does Not Heat Up

1.

The HEAT light
is ON



The heating
element has failed



Check also that the SSR is working
correctly

2.

The HEAT light
is OFF



The controller
shows a very high
temperature or a
code such as S.br



The thermocouple has broken or has a
wiring fault
 The controller
shows a low
temperature



The door switch(es) (if fitted) may be
faulty or need adjustment

 The contactor (if fitted) may be faulty

 The SSR could be failing to switch on due
to internal failure, faulty logic wiring from
the controller, or faulty controller

 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
temperature



The thermocouple may have been shorted
out or may have been moved out of the
heating chamber

 The thermocouple may be mounted the
wrong way round

 The controller may be faulty

2.

The HEAT light
does not go off
with the
instrument
switch



The SSR has failed
“ON”



Check for an accidental wiring fault which
could have overloaded the SSR

12 MF12 3.12

7.0 CIRCUIT DETAILS

Instrument Switch

coil

slave

controller

thermocouples

overtemp.
controller

thermocouple

safety

switch B

SSR

heat

on

safety

switches A

F3

F1

F2

F3

L

PE

Filter (if fitted)

contactor

if fitted

if fitted

master

controller

SSR

SSR

slave

controller

F3

F3

main

ref.

slave

slave

+ + +

– – –

F2 F2

Transformer

Instrument Switch

Safety Switches type A: a 2-pole Heater Switch is fitted directly in the element circuit in models

up to 16A rating.
Safety Switch type B: a Heater Switch is fitted into the contactor coil circuit in models over 16A.

7.1 Single Phase (example for TZF, control method A)

7.2 2- or 3-Phase

See also section Error! Reference source not found.. for certain models.

Each SSR is connected to a different phase. The control circuit is taken between L1 and N.
Safety switch A applies for 2-phase. Safety switch B applies for 3-phase.
If type F1 fuse is present, one per phase if fitted. If type F2 fuse is present, one is fitted; if type F3

fuse is present, one per phase is fitted.
Note that on 2- or 3-phase models there may be three separate neutrals taken to a common supply

terminal, depending on EMC filter requirements.

7.3 Higher Voltages

For 254V or above (or 440V, 3-phase) an isolating transformer is

fitted in the control circuit after the F2 fuses.

MF12 3.12 13

Independent Zones (control method C)

F1

Internal
supply
fuses

Fitted if supply cable fitted.
Fitted on board to some types of EMC filter.

on-board and up to 16 Amps:
32mm x 6mm type F

other: GEC Safeclip

F2

Auxiliary
circuit
fuses

Fitted on board to some types of EMC filter.
May be omitted up to 25Amp/phase supply

rating.

2 Amps glass type F
On board: 20mm x 5mm
Other: 32mm x 6mm

F3

Heat Light
fuses

May be omitted up to 25 Amp/phase supply
rating.

2 Amps glass type F
32mm x 6mm

Customer
fuses

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

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

Model

phases

Volts

Supply
Rating

Volts

Supply
Rating

TZF 12/38/400

1-phase

200-240

7A

110-120

12.5A

TZF 12/65/550

1-phase

200-240

10A

110-120

20A

TZF 12/65/550

2- or 3-phase + N

380/220 - 415/240

5A

TZF 12/75/700

1-phase

220-240

12.5A

110-120

25A

TZF 12/75/700

1-phase

208

15-16A

100

30-32A

TZF 12/75/700

2- or 3-phase + N

380/220 - 415/240

7A

TZF 12/100/900

1-phase

200-240

20A

110-120

40A

TZF 12/100/900

2- or 3-phase + N

380/220 - 415/240

15-16A

HD
HE
HF

HD
HE
HF

HD
HE
HF

master

slave

slave

When this is ordered there are three independent thermocouples (instead of the four shown)

connected to the three controllers; the words “master” and “slave” may be replaced by “centre”

and “end”.

7.4 Control by Broadcast comms (control method B)

When this is ordered there are three independent thermocouples (instead of the four shown)

connected to the three controllers; the controllers are linked together (not shown), and remain

“master” and “slave”.
The communication between the controllers of the Eurotherm 3000 series is known as Broadcast

comms. The wiring connections between the controllers are as follows:

8.0 FUSES & POWER SETTINGS

8.1 Fuses
F1-F3: refer to the example circuit diagram.

Access to internal fuses is by removal of the back panel of the furnace base or control box.

other models or voltages: check the rating label for details of the supply.

8.2 Power Settings

14 MF12 3.12

The models covered by this manual are designed to run on 100% power, with the exceptions

Model Volts:

200V

208V

220V

230V

240V

380V

400V

415V

Equal zone models:
TZF 12/38/400E

TZF 12/65/550E

100

100

89

82

75 - -

-

Custom Models:
TZF 12/25/550

TZF 12/38/550
TZF 12/75/550
TZF 12/75/900

100

100

89

82

75 - -

­Standard Model:

TZF 12/100/900
(from April 2000)

100

100

89

82

75

89

82

75

below.

Other possible exceptions:
Further custom furnaces based on the standard models may be designed with power limits other

than 100%.
Furnaces supplied for use on 254 Volt typically have a power setting of 89% of the limit for the

corresponding 240V model.

MF12 3.12 15

Carbolite, Parsons Lane, Hope,

Hope Valley, S33 6RB, England.

Telephone: [phone]

Fax: [phone]

E-mail: [email protected]

The products covered in this manual are only a small part of the wide range of

ovens, chamber furnaces and tube furnaces 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: [phone]
Fax: [phone]
Email: [email protected]

MF12 – 3.12 14/08/14

MODEL

Max.

Temp.

Max.

Power

Work

Tube

Bore

Work

Tube

Length

Heated
Length

Uniform

Zone

Length1

Net

Weight2

(°C)

(kW)

(mm)

(mm)

(mm)

(mm)

(kg)

Tube furnaces with a ceramic work tube wound with resistance wire

TZF 12/38/400

1200°C

1.5

38

450

400

305

15

TZF 12/65/550

1200°C

2.0

65

600

550

392

25

TZF 12/75/700

1200°C

3.0

75

750

700

510

28

TZF 12/100/900

1200°C

4.5

100

950

900

745

35

also models based on the above, but of other diameters or lengths, supplied to special order

temperature:

5°C - 40°C

relative humidity:

maximum 80% up to 31°C decreasing linearly to 50% at 40°C

9.0 SPECIFICATIONS

Carbolite reserves the right to change specifications without notice.

9.1 Models Covered by this Manual

note 1: The figures for uniform zone length are for ±5°C and are based on

measurements with the furnace horizontal and fitted with insulating plugs in both tube
ends. They assume the use of master-slave control.

note 2: Weights are approximate for horizontal models and do not include fittings

or vertical stands.

9.2 Environment

The furnaces contain electrical parts and should be stored and used in indoor conditions as

follows: