Grant LTC2 User Manual

Low temperature
circulator

LTC2

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 Recommended liquids 6

4.3 Installation 7

4.4 Electrical supply 7

5.0 Operating procedures 8

5.1 Operation 8

5.1.1 Liquid level 8

5.1.2 Operation above 60°C 8

5.1.3 Using the pump 8

5.1.4 Emptying the LTC2 9

5.1.5 Setting up and switching on 9

5.2 Using the LTC2 10

5.2.1 Product description, control unit 10

5.2.2 Control unit product indicators 10

5.2.3 Product description, refrigeration unit front panel (grille removed) 11

5.2.4 Product description, refrigeration unit rear panel 12

5.2.5 Setting the control temperature 12

5.2.6 Selecting liquid type 12

5.2.7 Setting the over-temperature thermostat 13

5.2.8 Configuring a preset 13

5.2.9 Running a bath preset 14

5.2.10 Completing a calibration 14

5.2.11 Restoring factory calibration settings 15

5.2.12 Adjusting display brightness 15

5.2.13 Setting a countdown timer 15

5.2.14 Cancelling the timer 16

5.2.15 Setting a high temperature warning alarm 16

6.0 Technical specifications 17

6.1 Operating conditions 17

6.2 Electrical details 17

6.3 Performance 17

7.0 Technical Tips 18

7.1 Which water should you use in your bath? 18

7.2 How to prevent rust in water baths 18

7.3 How to prevent algae and bacteria? 19

8.0 Warranty information 19

9.0 Maintenance and service 19

9.1 Routine maintenance 19

9.2 Cleaning 19

9.3 Fuses 20

9.5 Routine safety tests 20

9.6 Service 21

10.0 Optional accessories 21

10.1 Alternative pump 21

11.0 Troubleshooting 22

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12.0 Contact Grant Instruments 24

13.0 Compliance 24
Notes 25

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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:

 LTC2 & LTC2L

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

The LTC2 consists of a TC120 immersion thermostat combined with an R2 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 this low temperature
bath/circulator 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 operating information for the
LTC2. Product technical specifications and tips are provided in sections 6 and 7. The
warranty for this product is for FOUR 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 LTC2 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.

For the LTC2, 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 LTC2 with flammable heat transfer liquids.

Do not use the LTC2 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 heater, 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 LTC2 weighs 25kg. Take necessary precautions when lifting.

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

-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 the 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 the local regulations.

4.1 Unpacking instructions

Standard equipment includes:

 LTC2 low temperature circulator
 Pump connector kit
 4 x Jubilee clips
 6m of insulated hose
 Mains cord

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

4.2 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 LTC2. If in doubt please
contact the Grant technical support team.

* See section 7.1 for further details

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4.3 Installation

Place the LTC2 on 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 bath. 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 LTC2 to a grounded (earthed) electrical power supply with voltage
and frequency within the range specified on the serial number plate.

The LTC2 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 LTC2).

4.4 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.

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 LTC2 is pumping.

B

A

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 4.2 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 Using the pump

The LTC2 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.

The LTC2 is supplied with insulated hose which is designed to operate at temperatures
between -40˚C to 80˚C. We recommend that suitable high temperature hose is used for

temperatures above 80˚C.

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