Grant LTC4 User Manual

Low temperature
circulator

LTC4

Operating Manual

Grant Instruments, based near Cambridge, England is a world leader in the
manufacture and design of equipment for sample preparation, scientific analysis, data
acquisition and data analysis providing solutions to the global scientific and industrial
markets.

Standards Compliance and Quality

Grants’ brand and reputation are based around quality, reliability and accuracy. We
ensure our products stringently meet all necessary international safety standards.
We pay particular attention to the safety testing of products and remain at the forefront of
the product safety standard for laboratory equipment IEC 61010-1. The company is
committed to operating its safety test laboratory in accordance with the requirements of
ISO 17025.

Grant operates a Quality Management System that complies with the requirements of BS
EN ISO 9001:2008.

Beyond compliance to the standard, Grant is committed to continually improving in
everything we do; with particular emphasis on understanding what matters to our
customers and suppliers, and designing our systems and work to meet their needs.

If you have any feedback on Grant’s products or services we would like to hear from you.
Please send all feedback to:

Quality Manager
Grant Instruments (Cambridge) Ltd
Shepreth
Cambridgeshire
SG8 6GB
UK

Tel: [phone]
Fax: [phone]
E-mail: [e-mail]

Contents

Contents 2

1.0 Use of products 4

2.0 How to use this operating manual 4

3.0 Safety information 4

3.1 Safety compliance 4

3.2 Safety symbols 4

3.3 Safety warnings 5

4.0 Operating instructions 6

4.1 Unpacking instructions 6

4.2 Fitting the controller to the Refrigeration unit 6

4.3 Recommended liquids 6

4.4 Installation 8

4.5 Electrical supply 8

5.0 Operating procedures 9

5.1 Operation 9

5.1.1 Liquid level 9

5.1.2 Operation above 60°C 9

5.1.3 Setting the over-temperature thermostat 9

5.1.4 Using the control unit pump 10

5.1.5 Using the switch over relay ouput 10

5.1.6 Emptying the LTC4 11

5.1.7 Setting up and switching on 11

5.2 Using the LTC4 12

5.2.1 Product description, control unit 12

5.2.2 Product description, user interface and controls 12

5.2.3 Product desciption, rear panel connections 13

5.2.4 Communications ports 13

5.2.5 Switched relay port 13

5.2.6 External probe input 13

5.2.7 Product description, refrigeration unit front panel (grille removed) 14

5.2.8 Product description, refrigeration, rear panels 15

5.2.9 Display. Explanation of home screen icons. 15

5.2.10 Setting the control temperature 15

5.2.11 Running a bath preset 16

5.2.12 Running a countdown timer 16

5.2.13 Running a program 17

5.2.14 Activating standby mode 17

5.2.15 Accessing the settings menu 18

5.3 Viewing, editing and saving settings 19

5.3.1 Configuring a preset 19

5.3.2 Selecting a liquid type 20

5.3.3 Selecting a temperature probe type 21

5.3.4 Configuring high and low temperature alarms 22

5.3.5 Setting the buzzer volume level 25

5.3.6 Selecting a language 25

5.3.7 Relay test and configuration 26

5.4 Completing a calibration 27

5.4.1 Restoring factory calibration settings 29

6.0 Technical specifications 30

6.1 Operating conditions 30

6.2 Electrical details 30

6.3 Specification 30

7.0 Technical Tips 31

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7.1 Which water should you use in your LTC4 tank? 31

7.2 How to prevent rust in LTC4 tanks 31

7.3 How to prevent algae and bacteria? 32

8.0 Warranty information 32

9.0 Maintenance and service 32

9.1 Routine maintenance 32

9.2 Cleaning 32

9.3 Fuses 33

9.5 Routine safety tests 33

9.6 Service 34

10.0 Optional accessories 34

10.1 Alternative pump 34

11.0 Troubleshooting 35

12.0 Contact Grant Instruments 38

13.0 Compliance 38
Notes 39

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1.0 Use of products

Caution: Surfaces and heat transfer liquid can be hot during and after use.

Read this manual before using the bath.

Important safety warning.

The following products are covered by this operating manual:

 LTC4 & LTC4L

The products listed above low temperature circulators designed for indoor laboratory use
by a professional user.

The LTC4 consists of a TX150 immersion thermostat combined with an R4 refrigeration
unit, with insulated hoses and clips to allow circulation of temperature control fluids to
external equipment.

2.0 How to use this operating manual

This operating manual will allow you to unpack, set-up and operate the R unit correctly
and safely. Important safety information, symbols and warnings are listed below and
should be read carefully. Section 4 gives information about how to unpack and install the
product correctly. Section 5 gives provides operating information for the LTC4. Product
technical specifications and tips are provided in sections 6 and 7. The warranty for this
product is for THREE YEARS and is detailed in section 8 and should be registered by
completing the on-line registration form at www.grantinstruments.com.

If there is a technical matter that this operating manual does not address, or any other
question concerning this product, please contact Grant Instruments or your local
distributor, who will be able to provide any additional information.

3.0 Safety information

3.1 Safety compliance

The LTC4 meets the requirements of international safety standard IEC 61010: Safety
requirements for electrical equipment for measurement, control, and laboratory use.

3.2 Safety symbols

The symbols below are marked on the equipment and throughout this manual to indicate:

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3.3 Safety warnings

Read the whole of these instructions. Safety may be impaired if they are not
followed.

Only use liquids specified in these operating instructions, within the specified
temperature range. If the alarm lamp is illuminated the liquid temperature may
be above its recommended maximum. Do not inhale the vapours given off as
they may be toxic. Liquids should be safely discarded and replaced.

Do not use the R series unit with flammable heat transfer liquids.

Do not use the R series unit to heat any sample material that could cause a fire
or any other kind of hazard.

Do not use the equipment in an area where there are aggressive or explosive
chemical mixtures.

If a potentially hazardous liquid is spilt onto or inside the equipment, disconnect
it from the power supply and have it checked by a competent person.

Before moving, disconnect from the mains power supply

It is the user’s responsibility to carry out appropriate decontamination if
hazardous material is spilt on the equipment.

If the alarm lamp is illuminated do not touch the liquid or the tank base, they
may be very hot. Refill carefully, a hot heater can cause a spattering of very hot
water droplets and scalding steam.

Do not touch surfaces which become hot during high temperature operation.

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4.0 Operating instructions

The LTC weighs 39.5kg . Take necessary precautions when moving and lifting.

2

1

4.1 Unpacking instructions

Standard equipment includes:

 LTC4 low temperature circulator
 Pump connector kit
 4 x Jubilee clips
 6m of insulated hose
 Mains cord
 Operating manual

Remove packing materials carefully and retain them for future shipment or storage of the
equipment.

4.2 Fitting the controller to the Refrigeration unit

The TX150 unit can be fitted in two orientations on the LTC4 unit facing over the tank
opening or outwards

1. Remove the bridge plate from the LTC4 unit tank by unscrewing the four black thumb
screws.

2. Fit the Optima unit through the hole in the bridge plate and align using the locating
threads. Secure using the retaining nuts. Hand tighten only.

3. Re-attach the bridge plate onto the R unit, using the retained black thumb screws.

4.3 Recommended liquids

The following table lists the recommended liquids for different temperature ranges.
Always ensure the liquid used is safe and suitable for your working temperature. If using
non-recommended heat transfer liquids, it is the responsibility of the user to conduct an
assessment to ensure the intended fluid is compatible with the LTC4. If in doubt please
contact the Grant technical support team.

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To ensure protection the overtemperature cut-out must be set appropriately for
the heat transfer liquid selected (see table below).

If using non-recommended heat transfer liquids it is important to set the over­temperature cut-out to a value no higher than 25°C below the fire point of the
liquid.

Use fume extraction when using silicone fluids at elevated temperatures

Temp range

Recommended liquid

Comments

-50°C to 50°C

Silicone oil – low
viscosity

Bayer silicone M3. Follow the manufacturer’s

instructions. For safe disposal consult your
local regulations.

-30°C to 30°C

50% water, 50%
antifreeze (inhibited
ethylene glycol)

WARNING: Ethylene glycol is toxic – follow the
manufacturer’s instructions.
For safe disposal consult your local
regulations.
Use a lid to reduce the dilution of the mixture
caused by condensing water vapour from the
air, and to maintain the cool down rate.

0°C to 30°C

80% water, 20%
antifreeze (inhibited
ethylene glycol)

5°C to 99.9°C

Water*

Water can be used but care should be taken
above 60°C as hot vapour can be dangerous.
Use a lid or polypropylene spheres above
60°C to ensure good performance & reduce
evaporation.
At temperatures approaching 99°C the
temperature performance will be affected due
to localised boiling.
The units should not be used to boil water.

70°C to 120°C

Silicone fluid
Viscosity ~20cs

Flash point ≥230°C
Fire Point ≥280°C

Dow Corning DC200/20 silicone fluid is a
suitable liquid – follow the manufacturer’s
instructions.
For safe disposal consult your local
regulations.

* See section 7.1 for further details

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4.4 Installation

Place the unit a level, non-combustible surface. Ensure that the mains plug and
the switch at the rear of the unit are easily accessible.

If the equipment has been transported or stored in cold or humid conditions,
condensation may form inside it. If that could have happened, allow time (at
least 2 hours at room temperature) for the condensation to evaporate before
using the equipment.

Do not block or restrict ventilation slots.

Do not connect to a power supply or switch on before filling the tank.

Drain before moving the unit. Before draining allow the liquid to cool below
50˚C.

Do not touch the condenser fins, they are sharp and may cause injury.

Connect the LTC4 to a grounded (earthed) electrical power supply with voltage
and frequency within the range specified on the serial number plate.

The LTC4 must only be connected to the mains using the mains cord supplied
or one with an identical rating (see section 9.4)

Ensure the mains switch and isolating device (power supply connector) are
easily accessible during use.

After transportation, let the unit stand in its intended working position for six hours. This
is to allow the oil to drain to the bottom of the compressor. This is normal procedure for
refrigeration compressors. Allow at least 100mm clearance from obstructions on all
sides so that there is free air flow through the unit, from the front to the back (this also
has the advantage that air is not blowing directly out of the sides onto instruments next to
the LTC4).

4.5 Electrical supply

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5.0 Operating procedures

Take care when lifting and removing the lid as it may be hot. Steam and hot
vapours can cause scalding.

5.1 Operation

5.1.1 Liquid level

Fill the tank to an appropriate level with a liquid suitable for your working temperature;
see section 4.3 for liquid options. Allow for thermal expansion and contraction of the
liquid during operation and for any liquid in external circulation paths. If using liquids that
can evaporate then periodic checking and refilling should be completed. The low level
float switch will alarm if the liquid level drops below the minimum required level and the
unit will switch off the heater and stop temperature control.

5.1.2 Operation above 60°C

A lid or polypropylene spheres must be used above 60°C to maintain temperature control
and to ensure that the bath fluid temperature reaches the set point. They will save
energy by preventing excessive evaporation and reduce the frequency that the bath
needs to be refilled.

5.1.3 Setting the over-temperature thermostat

An over-temperature cut-out dial with a temperature scale is located at the top right of the
unit. The over-temperature probe independently monitors the bath temperature and
switches the heater off if it goes above the cut-out threshold.

Coarse setting of the over-temperature thermostat

Rotate the temperature cut-out dial in line with the marked scale to the desired setting.
This should be higher than the set temperature to avoid operating the cut-out before the
set temperature has been reached.
If the alarm is triggered the sounder can be silenced by pressing either the F or S button
once. To continue to use the TX150/TXF200, let the bath liquid cool by at least 5°C,
either naturally or by replacing the liquid, switch the unit off, wait 10 seconds and switch it
on again to clear the alarm. To avoid nuisance tripping the trip point needs to be set at
least 5°C above the desired control temperature.

Alternative setting of the over-temperature thermostat

Rotate the temperature cut-out dial to maximum (or at least a value above the level
required) and configure the set temperature to the cut-out level required. Leave the bath
to reach the set temperature and stabilise for at least 5 minutes. Turn the cut-out dial
slowly anticlockwise until an over-temperature fault is displayed on screen and the alarm
sounds continuously. This gives an over-temperature trip point at the set temperature.
The audible alarm can be cancelled by pressing either the F or S button once.

To continue to use the TX150/TXF200, let the bath liquid cool by at least 5°C, either
naturally or by replacing the liquid, switch the unit off, wait 10 seconds and switch it on
again to clear the alarm. To avoid nuisance tripping the trip point needs to be set at least
5°C above the desired control temperature.

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5.1.4 Using the control unit pump

Always use pump connectors and hoses that are suitable for the operating
temperature and liquid used. Check the pipe connections are secure.

Never disconnect any pipes or hoses while they contain very hot or very cold
liquids or while the LTC4 unit is pumping.

Never use silicone oil with silicone tubing.

3 2 1

Normally Closed

Normally Open

Common

Rear
Panel
connector

Relay

B

A

The LTC4 allows liquid to be pumped around a closed external system (not open to the
atmosphere). It cannot be used for circulation through an external open tank. The pump
is fitted with a blanking plate as standard. Fit a pump connector plate as shown below.
Ensure o-rings are located in the grooves, use silicone grease to hold the o-rings in
place. Note: the blanking/connector plates have a locating hole (see A below) to assist
correct alignment onto the pump moulding. It is important to verify the hole is aligned with
the corresponding locating pin (see B below) on the pump moulding. Failure to do so will
result in a leaking connection. Retain the blanking plate for refitting when the pump is no
longer required.

Pumping heat transfer liquid around an external system can lead to hazards that are
outside the control of Grant Instruments. It is essential that the user conducts a risk
assessment of the entire equipment installation to ensure that correctly rated materials
have been used throughout and that the system can be used safely.

5.1.5 Using the switch over relay ouput

An internal relay provides switch over contacts that can be used to control external
equipment. The pin connections on the rear panel 3 pin circular connector are:

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For the connecting cable use a mating XLR style connector such as the NC3FXX

The relay is rated 24Vac or dc at 2A; to prevent injury or equipment damage,
do not connect to greater voltages or attempt to switch greater currents.

Voltages as low as 22Vac can be hazardous in locations where wetting of the
skin can occur. When making up cable to connect your equipment to the relay
connector, on the TX150/TXF200, make sure that the insulation system used is
adequate to provide protection against the voltages output by your equipment
for switching by the relay.

Always use the correct size cable with correct class of insulation for the voltage
being switched. If in doubt contact the technical support team at Grant.

Allow the liquid temperature to fall below 50˚C before emptying.

Ensure all hoses are connected securely. Liquid will begin pumping
immediately once LTC4 is switched on.

manufactured by Neutrik AG
The switch over contacts are rated at 24V AC or DC 2A maximum.

5.1.6 Emptying the LTC4

The R unit tank should be emptied to a safe level prior to moving. A drain tap is included
on R2, R3, R4 & R5 units to allow convenient emptying. See section 5.2.3 for full details.

5.1.7 Setting up and switching on

Follow instructions in section 5.1.3 to attach the pump connector plate and insulated
hose. Before filling and switching on, attach the open end of the hose to the application,
taking care to note the inlet and outlet.

Add the appropriate working liquid to the bath to at least the minimum recommended fill
level such that the float level switch is fully raised.

The control unit is connected directly to the mains supply with the IEC cable supplied
with the unit (230V units only).

Connect the refridgeration unit directly to the mains using the IEC cable provided).
Switch on the LTC4 control unit using the power switch on the rear. The motor will start

immediately and the buzzer will sound while the unit starts up. Switch on the
refrigeration unit using the power switch on the front of the unit. The LTC4 will start to
control at the set temperature

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5.2 Using the LTC4

Over-temperature dial

Full colour display

Select button

Main dial

Float switch

Heater coils

Pump outlet plate

Function button

5.2.1 Product description, control unit

5.2.2 Product description, user interface and controls

The TX150 features a full colour graphic display, a main dial and two buttons F and S.
All functions (setting temperature, pump speed, countdown timer, presets, programs
settings and standby mode) can be configured from the home screen. Navigation around
the home screen is achieved by rotating the main dial which moves a white curser to
highlight function icons. Pressing the S button whilst the icon is highlighted will change
the colour of the curser to red, make the icon active and allow changes to be made, or in
the case of the settings icon, further menus to be displayed.

The primary function of the F button is to exit functions and menus. If F is pressed when
in the home screen whilst the cursor is white the settings menu is displayed

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5.2.3 Product desciption, rear panel connections

RS232 communcations
port

Mains power input

USB port

Switched relay port

External probe input

5.2.4 Communications ports

The TX150 and TXF200 provide a RS232 and a USB data port for communication with a
PC running Grant Labwise™ software. Labwise™ provides the abilty to remotely
configure, control, monitor programs as well as log program temperature data.
Only use a RS232 cable supplied by Grant instruments.
The USB cable is a Type A to Type B style

5.2.5 Switched relay port

An internal relay provides switch over contacts that can be used to control external
equipment. See Section 5.1.5 for details of the relay contacts and connector type.

5.2.6 External probe input

For connecting an external PT1000 thermocouple temperature probe available from
Grant instruments

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