Grant Instruments LTC4 - Manual (Page 10)

31115 V1 LTC4
Page 9 Operating Manual
www.grantinstruments.com
5.0 Operating procedures
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.
Take care when lifting and removing the lid as it may be hot. Steam and hot
vapours can cause scalding.
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.