Taylor-Wharton CS Series - Manual (Page 18)

16
CS SERIES
In addition, inspection and preventive maintenance should also be performed on
the freezer and its mechanical parts. Refer to owner’s manual for details.
If any intermittent alarm or defect with the Cryo-Storage System is observed or
suspected, it should be investigated and remedied immediately even if this falls
outside of the normal maintenance schedule.
CONTROLLER OPERATION
This section of the operating manual is for Taylor-Wharton approved equipment that
uses the CS SERIES Control System.
Introduction
The CS200 Control System, temperature and LN
2
level controller is designed for
easy operation and uninterrupted reliable service. This controller will maintain the
selected liquid level range of LN
2
in your refrigerator as well as provide audible
and visual alarms for any non conforming conditions that may occur. An Alarm
is any condition outside the activated preset limits on the control, such as an
open sensor circuit or temperature alarm. “System Events” are lid openings and
closings, solenoid valve openings and closing, and operation of the controller’s
relay for remote alarm indication. System Events, Alarms and Temperature “Data”
can be downloaded.
The System should require no additional attention to maintain liquid level if an
adequate supply source of liquid nitrogen is maintained. If your protocol calls for
you to “top-off” the Cryostorage System at the end of a workday or workweek,
press the FILL button. The unit will fill to the upper allowable liquid level and stop
automatically. You may choose to manually stop the fill by pressing the STOP
button at anytime during the fill.
Operation Data
The CS200 CONTROL SYSTEM stores data related to the operation of the Taylor-
Wharton Cryo-Storage freezer. This data includes date, time, LN
2
level, temperature,
system events and error conditions. This can be useful for audit purposes, operation
analysis and preventive maintenance.
Communications
The CONTROL SYSTEM has been designed with advanced communications
capabilities. This allows for the transfer of data out of the control where the data
can more easily be used. Please check with your supplier for available protocols and
compatible products.
Normal Fill Cycle
When the refrigerator is filled and the controller is operating, the START FILL and
LOW ALARM sensors are immersed in liquid nitrogen. Their resistance values
are interpreted by the controller as “in liquid”. At the same time, the STOP FILL
and the HIGH ALARM sensors are above the liquid pool, informing the control
that these sensors are in vapor. As liquid nitrogen evaporates, the liquid level
in the refrigerator drops slowly until the START FILL sensor is above the liquid
and sends a different signal to the controller. After a delay sufficient to ensure
the signal, the controller interprets this condition as low liquid and opens the fill
solenoid, admitting more liquid nitrogen from the supply source.
The refrigerator will fill slowly. The fill continues until the STOP FILL sensor sends
the controller a signal that it is now in liquid. The controller will close the liquid
supply valve to stop the fill. As liquid evaporates, the display will indicate the
liquid is at a normal level as the cycle begins again.