Grant Instruments LTC2 - Manual (Page 14)

30933 V2 LTC2
Page 13 Operating Manual
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5.2.7 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. For the LTC2, the
temperature cut-out threshold can be adjusted for convenience.
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, it can be cancelled by pressing either the F or S button once.
The unit must then be switched off to clear the cut-out alarm. To continue to use the
LTC2, 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 the alarm lamp comes on and the alarm sounds intermittently.
The display will alternate between showing “Cut” and the liquid temperature. 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 LTC2, let the liquid cool by at least 5°C, either naturally or by
replacing the liquid, switch the control unit off, wait 10 seconds or 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.
5.2.8 Configuring a preset
The LTC2 can be configured with three temperature presets to allow the circulator to be
conveniently run at frequently used temperatures. Use the method below to configure
preset 1; other presets can be set in a similar manner.
Be aware that once a preset has been saved using the steps below, it will automatically
start once all the steps have been completed.
1. Press the F button and rotate the dial until the display shows “t-1”.
The display will alternate between the preset number and its temperature.
2. Press the S button to select the preset.
3. Use the dial to set the desired preset temperature.
If no key is pressed for 10 seconds then the display will revert back to showing the
bath temperature and the preset temperature will remain at its original value.
4. Press the S button to save the preset temperature.
The preset will automatically start as soon as the value is saved.
Preset temperatures and set temperatures are limited to between -20°C and 120°C. The
factory preset settings are shown in the following table.