TE Technology TC-720 - Manual (Page 17)

When making a cooling system from a single TE module, the maximum operating voltage for that system is
usually no more than 75% of the rated Vmax of the TE module. 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 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 a voltage greater than the system maximum will not necessarily damage the
controller (unless voltage and/or current limits are exceeded), but the TE device could be damaged by
overheating as a result.
Power supply and TE Device wire leads should be kept to a length of one meter or less and of sufficient wire
size to reduce electrical losses in the wire and the likelihood of generating unwanted electromagnetic
interference. However, see also warnings about wire length under section 1.4.
Use protection devices to prevent hazardous conditions and/or damage to the TE device 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-720, the TE device, 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-720, the TE device, and related
equipment to be re-energized. Protection devices should include, but are not limited to:
• Fuses to defend against electrical overloads
• Over-temperature and/or 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-720 controller (in conjunction with the standard and optional sensors) can detect under-
temperature and over-temperature conditions, and it can be configured to de-energize the load when such
a condition is detected. However, hazards and/or risk of loss or damage to the cooling assembly 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.
Protect the USB circuitry from unwanted Electrostatic Discharge (ESD) by either (a) plugging the USB port
with the supplied USB dummy plug when not in use (TC-720), or (b) otherwise providing shielding via an
enclosure or other external design feature (TC-720 OEM).
Use the supplied rubber face plate gasket to prevent wires from abrading and shorting against metal case
(TC-720 only) and to protect the user from inadvertently contacting the circuit board.
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