TOHO ELECTRONICS TTM200 - Manual (Page 24)

48-7009-E 3-2
3.1 Precautions on wiring
Warning
Do not turn on the power until all wirings are complete in order to prevent an electric shock or equipment failure.
★ For inputs from a thermocouple, use the specified wires or compensating leads.
★ For inputs from a resistance temperature detector, use lead wires with small resistance and no resistance
difference is present among the 3 wires (3-wire type).
★ Provide input signal lines away from power supply lines, power lines or load lines so as not to affect input
signal lines with noise induction.
★ Wire the power supply for instruments such that they do not receive noises from the power supply for
power devices.
The use of a noise filter is recommended in case that the equipment is vulnerable to noises.
Take note of the following points when using a noise filter.
◎ Install the noise filter as close to a temperature controller as possible.
Wire the instruments in as short a distance as possible to output lines (secondary side) of the noise
filter and power terminals for the temperature controller.
◎ Isolate the noise filter input line (primary side) from its output line (secondary side).
High-frequency elements of noises may be induced, resulting in no provision of much noise
attenuation effect as expected, in case of input and output wires being close one another, such as
being bundled together or installed in a same duct or tube.
◎ Wire the grounding wire of the noise filter in as short a distance as possible.
A long grounding wire is like inserting an inductance, resulting in deteriorated high-frequency
characteristics.
◎ Before installing the noise filter, peel off the paint applied on a mounting plate of the noise filter as
appropriate, in order to reduce the contact resistance between the noise filter and equipment housing.
★ For the power supply, use and twist wires that cause less voltage drop.
★ It takes about 4 seconds for the unit to activate after its power is turned on. Use delay relays when using
the equipment for generating signals for interlocking circuits.
★ When using the unit with 24 V power supply, supply the power from a SELV circuit (power supply
secured with safety).
★ When using the unit with DC24V power source, set ①-terminal to plus (+), ②-terminal to minus (-).
★ The equipment is not attached with power supply switch fuses. Separately install fuses in proximity of
the equipment, as needed.
◎ Recommended fuse rating: Rated voltage of 250 V and rated current of 1 A
★ Use crimping terminals that match the screw sizes.
◎ Size of crimping terminal: Terminal width of 6 mm or smaller
Crimping terminal recommended
Manufacturer: NICHIFU
Model: ICTV-1.25Y-3N (Y terminal)
ICTV-1.25-3S (round terminal)
◎ Tightening torque recommended: 0.5 N 
m (5 kgf

m)
◎ Applicable wire
Use wires in sizes suitable for the terminals.
The use of shielded wires is recommended.
For Pt100 (resistance temperature detector), use identical wires of low lead resistance and no
resistance difference among 3 wires.
★ For the communication ,use a shielded twisted pair cable.
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