ThermoFlex-Manual - 第101页
Section 7 ThermoFlex 7-13 Thermo Scientific V erifying/ Adjusting the Controller PID V alues (T une Loop) The controller controls temperature using a Propor tional-Integ ral- Deriv ativ e (PID) alg orithm. Should your chi…
Section 7
7-12 ThermoFlex
Thermo Scientific
Chiller will not circulate process uid
Check the reservoir level. Fill, if necessary.
Ensure the reservoir bag lter is not clogged.
Check the application for restrictions in the cooling lines.
Chiller requires >3 PSIG application pressure drop. If a bypass valve
has been installed add some restriction to the bypass line.
The pump motor overloaded. The pump's internal overtemperature
overcurrent device will shut off the pump causing the ow to stop. This
can be caused by low uid, debris in system, operating chiller in a high
ambient temperature condition or excessively conned space. Allow
time for the motor to cool down.
Make sure supply voltage matches the chiller's nameplate rating ±10%.
Inadequate temperature control
Verify the setpoint.
If the chiller is over-cooling, recycle the power.
Make sure the condenser/air lter is free of dust and debris.
Check the uid concentration, see Section 3.
Ensure chiller installation complies with site requirements, see Section 3.
Make sure supply voltage matches chiller nameplate rating ±10%.
For ThermoFlex900 - 5000 global voltage chillers ensure the chiller is
properly congured, see Appendix B.
If the temperature continues to rise, make sure your application's heat
load does not exceed the rated specications.
Check for high thermal gradients (e.g., the application load is being
turned on and off or rapidly changing).
Verify/adjust controller PID values, see next page.
Please contact Thermo Fisher Scientic Sales Service and Customer
Support if you need any additional information, see this manual's inside
cover for contact instructions.
Section 7
ThermoFlex 7-13
Thermo Scientific
Verifying/
Adjusting the
Controller
PID Values
(Tune Loop)
The controller controls temperature using a Proportional-Integral-
Derivative (PID) algorithm. Should your chiller experience temperature
control issues, verifying/adjusting the controller's PID values may correct
the condition.
Note Thermo Fisher recommends that only a qualied technician adjust
the PID values. Incorrect values will hamper chiller performance.
• Pro
proportional value
P = % of span (100°C)
Range: 0.0 to 99.9
Factory Preset:
ThermoFlex900-5000
10.0
ThermoFlex7500-10000
20.0
ThermoFlex15000-20000
30.0
ThermoFlex24000
40.0
• int
integral value
I = repeats/minute
Range: 0.00 to 9.99
Factory Preset: 0.50
• dEr
derivative value
D = minutes
Range: 0.0 to 9.9
Factory Preset: 0.0
Figure 7-1 Verifying/Adjusting PID Values
indicates press and hold.
tunE
Pro
int
dEr
enter
StorE
xx.x C
mode
mode
CAL
mode
xx.x
xx.x
xx.x
xx.x
x.xx
x.x
enter
enter
enter
enter
enter
enter
Section 7
7-14 ThermoFlex
Thermo Scientific