Grant Instruments LTC2 - Manual (Page 23)

LTC2 30933 V2
Operating Manual Page 22
www.grantinstruments.com
11.0 Troubleshooting
Symptom Possible cause Action required
Display shows
“Cut” Over-temperature
cut-out has operated Check the set temperature is correct and that
the over-temperature cut-out temperature is
set at least 5°C above the set temperature.
Refer to section 5.2.7 for setting instructions.
If the over-temperature cut-out temperature is
correctly set but the unit still shows a “Cut”
alarm then the unit has an internal fault and
must be repaired before it is used again.
Temperature
does not rise
when expected Set temp is lower
than liquid temp
Set temperature is
too close to ambient Check that the bath set temperature is correct
(see section 5.2.5).
Increase the set temperature (see section
5.2.5)
Temp continues
to rise when not
expected Set temp is higher
than liquid temp
Check that the bath set temperature is correct
(see section 5.2.5).
Unit fails to cool Compressor
overheated causing
internal over-
temperature
thermostat to operate
Wait for compressor to cool, when thermostat
will reset and compressor will switch on
again.
Alarm light on Over-temperature
cut-out has operated
Low liquid level float
switch has operated Check the over-temperature cut-out is set
appropriately (see section 5.2.7).
Check that the liquid level in the bath is
adequate.
Set temperature
too restricted Liquid type set does
not allow required set
point Change to different liquid type (see section
5.3.5).
Display shows
“Flot” Liquid level has
dropped below
minimum level Check that the liquid level in the bath is
adequate.
Display shows
“–Al-” High temperature
warning alarm has
tripped Check that the bath set temperature is correct
(see section 5.2.3).
Check that high temperature alarm is correct
(section 5.3.4).
Check that the liquid level in the bath is
adequate (see section 6.3 for minimum fill
levels).
Display shows
“Er H” Incorrect calibration
value The high temperature calibration point is less
than 40°C above the low calibration point –
choose a higher temperature (see section
5.2.10).