CS200
Control Systems
20
This section of the operating manual is for Worthington Industries approved equipment that uses the CS200
SERIES Control System.
Introduction
The CS200 Control System, temperature and LN
2
level controller is designed for easy operation and reliable
uninterrupted service. This controller will maintain the selected liquid level range of LN
2
in your freezer as
well as providing 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 closings, 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 available. 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 Worthington Industries Cryostorage
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 CS200 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 freezer is filled and the controller is operating, the
START FILL
and
LOW ALARM
sensors are
immersed in LN
2
. 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 LN
2
evaporates, the liquid level in the freezer 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 level and opens the solenoid valve, admitting more liquid nitrogen from
the supply source.
The freezer 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 solenoid valve to stop the fill. As liquid evaporates, the display will
indicate the liquid is at a normal level as the cycle begins again.
Control Setting Adjustments
Level
The standard sensor assembly that is installed on a freezer consists of a circuit board with thermistors installed.
The assembly has a maximum range of 6 in. (152 mm). Thermistor assignments can be changed through the
menu system and the operating range can be changed by either raising or lowering the thermistor sensor
assembly (offset) within the freezer.
Controller
Operation
Summary of Contents for CS200
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