Service/maintenance
Chapter 7
OPERATION MANUAL
V1.2.0en/12.05.15//14.06
Liability for errors and misprints excluded.
Unistat® T300 Series
81
This is not an actual leak but residues that are necessary for the lubrication of the mechanical seal.
The exiting quantity of thermal fluid is dependent on the thermal fluid itself and the working tem-
perature of the temperature control unit. The drops in the drip tray usually evaporate in case of
thermal fluids with a high vapor pressure. The drops usually do not evaporate in case of thermal
fluids with a low vapor pressure (e.g. silicone oils). Therefore, these residues must be drained from
time to time.
PROCEDURE
Hold a suitable container, e.g. beaker, below the
>Drain drip tray<
[7]. The drips can be cleanly
collected in the beaker and properly discarded.
Open the
>Drain drip tray<
[7].
Collect the drips.
Close the
>Drain drip tray<
[7].
7.4
Thermal fluid inspection, replacement and circuit cleaning
The illustration “Wiring diagram” can be found on page 89 in section
.
7.4.1
Thermal fluid inspection
Thermal fluid is not inspected on a regular basis
BURNS DUE TO REDUCED BOILING POINT
Regularly check your thermal fluid whether it meets the specifications in the safety data sheet.
Thermal fluid is not inspected on a regular basis
DAMAGE TO THE HEAT EXCHANGER AND/OR ELECTROMECHANICAL PARTS.
Regularly check your thermal fluid whether it meets the specifications in the safety data sheet.
Oxidation
Oxidation ages the thermal fluid and changes its characteristics (e.g. reduced boiling point). The
reduced boiling point may cause overflow of very hot thermal fluids at the
>Expansion vessel<
[18]
during temperature control of high temperatures. It may cause serious burns of the limbs.
Hygroscopy
During continuous temperature control below room temperature the thermal fluid accumulates
water by hygroscopicity over time. Such a liquid mixture causes the evaporator to burst during
temperature control in the minus range. This is caused by the water in the liquid mixture, which
forms ice crystals on the evaporator. A temperature control of such a liquid mixture at high tem-
peratures reduces the boiling point. A temperature control at high temperatures may cause an
overflow of very hot thermal fluid at the
>Expansion vessel<
[18] as a result of the reduced boiling
point. It may cause serious burns of the limbs.
7.4.2
Thermal fluid replacement
7.4.2.1
Externally closed application
To replace the thermal fluid, proceed from page 57 in section
»Externally closed application«
. The
draining and filling operations are described in this section.
7.4.2.2
Externally open application
To replace the thermal fluid, proceed as described on page 62 in section
. The draining and filling operations are described in this section.
