Stirling SU105U, Operating Manual

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8
03.2012.1
Operating Manual:
SU
105
U
-86
˚C
Ultra Low Storage
2. Features of the SU105U freezer
2.1 – Free-Piston Stirling Engine (FPSE)
The SU105U Ultra Low Temperature Freezer uses the
state of the art Stirling Ultracold Model M150A free-
piston Stirling engine (FPSE) to provide high efficiency,
deep-temperature cooling. No HCFC or CFC refrigerants
are used in the M150A and SU105U. The M150A Stirling cycle engine uses approxi-
mately 2 grams of helium gas as a working fluid. The secondary coolant loop uses
60 - 65 grams of refrigerant, R-508B (“SUVA® 95” *), as a working fluid.
2.2 – Cabinet Design Features
The cabinet is VIP insulated with polyurethane foam support providing an internal
volume of cabinet approximately 105 liters. The blowing agent is HFC R245a. A
locking cam door latch ensures door gasket compression when closed. Door sealing
consists of three gaskets and is factory replaceable. A door defrost minimizes water
or ice deposition on the gasket interface.
2.3 – Temperature Monitoring Features
Two resistance temperature detectors (RTDs) measure the internal cabinet tempera-
ture of the SU105U. One provides input to the FPSE controller and the other provides
input for the Swift GUI display and for reporting and logging. The display RTD may be
user calibrated through the Swift GUI. The Swift GUI provides a door open timeout
alarm and monitors the temperature reporting RTD for excursions beyond high and
low limits that are set automatically or manually. Alarms are reported through an
audible alarm in the freezer enclosure and through a contact closure that may be
connected to an external alarm. The Swift GUI provides options to temporarily sup-
press alarms and set a delay time before the alarm is reported via the contact closure.
A one-time temperature alarm suppression provided by the Swift software allows for
the initial cooling of the freezer after start-up.
AC power from 90 to 264 Volts is allowable, with a maximum current draw of about
3.0 Amps at 110 V and 1.5 Amps for 240 V.
* Trademark DuPont.