Czaki EMT-200, Руководство по эксплуатации

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10.1 Power supply
Due to safety reasons the power supply cables should be fixed to
terminals as the last ones, and should be disconnected from the power
network prior to this operation.
10.2. Sensor
A thermocouple sensor should be connected to the meter through a
compensatory cable suitable for the specific sensor type. Otherwise,
varying in time compensation error will appear and it can reach significant
values. The grade of the used thermocouple influences also the precision
of temperature measurements. It especially concerns the range of higher
temperatures.
In case of using a thermoresisistor sensor it is important to assure
using the largest possible cross-section of conductors connecting the
sensor to the meter. In the 3-wire method the sensor should be connected
to the meter by three identical conductors. If the distance between the
meter and the conductor is short it is admissible to connect these two
objects by two conductors. Nevertheless errors introduced by this 2-wire
method (1ºC for each 0,4 of conductor resistance) should be taken into
account.
10.3. Alarm circuits
If the voltage of the power supply in the alarm circuit exceeds 24V then
due to safety reasons electric connections in relay contact circuits can be
executed only after disconnecting the power supply.
It should be remembered that the load of relay contacts should have
resistive character, motors or condenser batteries are not admissible. For
the latter cases intermediary contactors or other external relay elements
should be used unconditionally. Taking into account the relay durability it is
advisable to use an external contactor in case the output current exceeds
1 A. If the above recommendations are not observed relay contacts will
wear out and lose their connecting properties fast.
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