TE Technology TC-36-25-RS232 - Manual (Page 15)

holder tines to ensure the new fuse will have good electrical contact to the fuse holder. In any case, an
external fuse, appropriately sized for protecting the TE device, should be connected between the
controller and the TE device to prevent damage and to prevent injury to the user should an over-current
condition occur with a TE device rated for less than 25 A. Alternately, a power supply with integral over
current protection can be used if it is appropriately sized for protecting the controller/TE device.
When making a TE device from a single TE module, the maximum operating voltage is usually no more
than 75% of the rated Vmax of the TE module for cooling applications. The 75% rule is based on the TE
module being thermally connected to a “good” heat sink; system modeling should be done to verify this
rule is applicable though. If multiple TE modules are used in an electrical series or series-parallel
combination, the Vmax of the system will be approximately 75% of the rated Vmax of each TE module
multiplied by the number of modules in series. Applying an input voltage to the controller that is greater
than the Vmax of the system will not necessarily damage the controller (unless voltage and/or current
limits are exceeded), but the TE module(s) could be damaged by overheating as a result.
Power supply and TE Device wire leads should be kept as short as possible to minimize electrical losses
and reduce the likelihood of generating unwanted electromagnetic interference. Use wires of a sufficient
gage appropriate to the amount of electrical energy each wire is to carry. Wire insulation and size must
also be appropriate to the ambient temperature and/or temperature of objects in contact with the wire.
Wire leads supplied by TE Technology are for prototyping purposes and should be reviewed for
appropriateness in the final application.
Use protection devices to prevent hazardous conditions and/or damage to the load (e.g. cooling assembly,
heater, etcetera) and other related equipment. Protection devices must operate independently of the
temperature controller circuitry. Protection devices should be placed at all points on the load and related
equipment where a hazardous condition can be detected. These protection devices should de-energize
the TC-36-25 RS232, the load, and, as necessary, other related secondary equipment. It is further
recommended that such devices require the user to remove and correct the root cause of a fault before
allowing the TC-36-25 RS232, the load, and related equipment to be re-energized. Protection devices
should include, but are not limited to:
•
Fuses to prevent against electrical overloads,
•
Over/under temperature thermostats to prevent against hazardous and/or damaging temperatures,
•
Liquid flow meters to prevent against damage due to loss of coolant flow
The TC-36-25 RS232 controller (in conjunction with the standard and optional sensors) can detect under-
temperature and over-temperature conditions as well as over-current conditions, and it can be configured
to de-energize the load when such conditions are detected. However, hazards and/or risk of loss or
damage to the load (e.g. cooling assembly, heater, etcetera), and/or secondary equipment could still occur
if the temperature controller and/or sensors were to malfunction. Therefore, independent, redundant
protection devices are recommended in addition to the safeguards provided by the temperature
controller. For the purposes of this manual the temperature controller and sensors are not considered
protection devices.
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