MVE Biological Systems
TEC 3000 Operating and Maintenance Freezer Manual
13289499 Rev H •
118
assembly using Teflon tape if needed. Ensure the filter is oriented correctly.
4. Reconnect the LN2 transfer hose, open the LN2 supply valve and check fittings for any leaks.
Complete Function Test
MVE recommends that freezers with TEC 3000 controllers undergo a complete function test every
12 months to ensure correct functionality and identify potential problems before symptoms develop.
Function test documents can be written based on this manual or this manual itself can be used to
verify the function of MVE freezers with TEC 3000 controllers.
Solenoid Valve Replacement
All MVE freezers are equipped with electromechanical solenoid valves that have been tested and
approved by MVE for cryogenic use. These valves utilize a PTFE seal for optimal sealing in
cryogenic environments. Over time, the normal thermal cycling that this seal is subject to will cause
it to harden and lose its ability to seal completely. This will result in seepage past the sealing
surface which can increase the LN2 consumption of the system, and in extreme cases result in an
overfill situation. Thermal cycling through normal operation can also cause moisture ingress into the
coil of the solenoid valve. Over time this may cause the connections and wiring in the coil to
corrode and eventually fail. This will result in an inoperative solenoid valve.
NOTE: over the life of MVE freezer, several different interchangeable 24VDC solenoids have been
used. The current model is pictured below. Always use replacement solenoid valves from MVE.
Substituting non MVE components may result in inoperable valves and even damage to the TEC
3000 control system. Damage to the control system due to use of non MVE parts will not be
covered by warranty.
SMC Solenoid Valve
(Current production)
SMC (black) Solenoid Valve Replacement
CAUTION
: Ensure that the LN2 supply valve is closed and the plumbing
assembly is vented before removing the solenoid valves.
1. Remove plumbing shroud (on HE and HEco series) or rear access panel (on MVE series)
to gain access to plumbing system
