No Temperature Control
If recirculating to an external system, do not exceed the cooling capacity
of the circulator. Exceeding the circulator's cooling capacity results in a loss of
temperature control.
No External Circulation
On ULT 80s, make certain adjustable Flow Control is open (turn counter-
clockwise).
Check for plug in external system line.
Recirculation will cease when pump head pressure is exceeded. Review
pump specifications (see Section II, Specifications).
No serial communications
All circulators are tested for serial communications before they leave the
factory. Ensure the REMOTE indicator on the controller is illuminated.
Check all communications commands, they must be exact. See Appendix A.
Check communications settings. The protocol uses an RS-232 serial interface
with the parameters: 9600 baud, 8 data bits, 1 stop bit and no parity.
Check all wiring for proper connections or possible shorts.
Software to verify serial communication is available from Thermo Fisher.
Service Assistance
If, after following these troubleshooting steps, your circulator fails to operate
properly, contact our Service Department for assistance (see Preface, After-
sale Support). Before calling please obtain the following information:
Part number
Serial number
Voltage of power source
Software version, see page 24
Technical Support
Our Service Department can provide you with a complete list of spare parts
for your circulator (see Preface, After-sale Support). Before calling, please
obtain the following information:
Part number
Serial number
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