Thermo Electron NESLAB System III, Installation-Operation- Installation-Operationbasic Service

Page: 13 / 28

- 11 -
Filling
Requirements
Remove the reservoir cover. Fill the reservoir with clean cooling fluid to
within 1 inch of the top of the reservoir. Have extra cooling fluid on hand and
follow the steps described in Section IV, Start Up.
Automatic Refill
Device (Optional)
The automatic refill device maintains the correct level of cooling fluid in the
reservoir. The device consists of a float switch in the reservoir and a solenoid
valve at the rear of the unit. If the cooling fluid level falls, the float switch will
drop, opening the solenoid valve and allowing make-up fluid to fill the reservoir.
Once the cooling fluid reaches the proper level, the float switch will rise and the
solenoid valve will close.
NOTE: For the solenoid valve to close properly, the minimum supply flow rate
should be 2.2 gallons per minute.
Connect the
3
/
8
inch OD stainless steel barbed fitting on the solenoid valve
to the make-up fluid source using
5
/
16
or
3
/
8
inch ID flexible tubing.
Tubing is available from Thermo. Contact our Sales Department for more
information (see Preface, After-sale Support).
Flow Control
The RECIRCULATING FLOW CONTROL handle is connected to a three-way
valve that controls the flow of the cooling fluid to the instrument being cooled.
The handle is located on the front of the unit.
When the handle is in the “+” position, the valve is open and all available cool-
ing fluid is supplied to the instrument being cooled. When the handle is in the
“0” position, the valve is closed and no cooling fluid is supplied to the instru-
ment being cooled. When the handle is between these two positions, the flow
rate of the cooling fluid is between full flow and no flow. Use the flow meter to
adjust the desired flow rate.
The gauge next to the flow control handle indicates the operating pressure.
Auto Restart
Units are equipped with an auto restart feature. If power is lost, the unit will
automatically restart when power is restored. This feature is enabled/disabled
using the controller's Setup Loop, see page 14.