Telemark Cryogenics 3600 - Defrost Recovery Period; Normal Operating Ranges

Telemark Cryogenics Microprocessor Based Cryochillers
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Revision 1.0.7 October 2018
monitors the returning gas temperature in determining if the
cryo-coil has been defrosted. If defrost terminates prematurely
check the discharge and water temperatures first.
When defrost ends the system automatically enters standby
this is indicated both on the display and by the standby button
illuminating.

3.1.5 Defrost Recovery Period
After defrost it is possible to enter cool immediately however,
better results (faster cycle times and lower temperatures) are
achieved if a short period (more than 4 minutes) in standby is
allowed for the system to recover. The recovery period is in
proportion to the defrost termination temperature and the
duration of the defrost cycle. A longer defrost period and the
higher termination temperature both increase the recovery
period. A good rule of thumb is if the discharge pressure is
less than 250 psi then it is fully recovered.
3.2 Normal Operating ranges .
The table below provides the range of acceptable parameters during
normal operation. Should observations reveal running out-side the
ranges as given below, then you should contact Telemark or their
representative at the earliest opportunity.

Description
Acceptable (normal) range
SP start up * Suction Pressure 20 to 120 psi
DP start up * Discharge pressure 100 to 470 psi
SP unit running 7 to 60 psi
BP (system off) System balance pressure 170 to 275 psi
CT Coldest temperature -100 to –150
o
C
LT Liquid Line temperature 10 - 30
o
C
CI Coil in temp +90
o
C to –140
o
C
CO Coil out temp +20
o
C to –140
o
C
IMPORTANT – turning the compressor on/off/on by
cycling the power or using the remote function to turn
on/off/on can cause damage to the compressor. False
alarms/failures may also occur as a result of cycling the
power to the compressor too quickly as gas pressures
inside the unit will not have sufficient time to equalize.
You
must allow 15-30 seconds before cycling the power
to the compressor.
Table 11 Normal Operating Ranges