51
4-3
Temperature Sensing Errors
Temperature Sensing Not Possible or Abnormal
Probable cause
Remedy
Connections
Polarity or wiring of a temperature sensor is
incorrect.
Correct the wiring of the temperature sensor.
Temperature sensor is not an applicable one.
Replace the temperature sensor with an
applicable one.
Leads of a temperature sensor are disconnected,
short-circuited, or deteriorated.
Replace the temperature sensor.
Temperature sensors are not used.
Use temperature sensors.
Thermocouple does not use applicable
compensating conductors.
•
Replace the thermocouple with another
thermocouple with long leads.
•
Connect applicable compensating conductors
for the thermocouple.
Thermocouple is connected to the E5ZE with a
device using a metal that is different in type from
the metal of the thermocouple or that of the
compensating conductors.
Connect a thermocouple-dedicated device be-
tween the thermocouple and the E5ZE.
A screw of the terminal block of the E5ZE is
loosened and improper contact is resulting.
Tighten the screw.
Leads or compensating conductors of a
thermocouple are too long and leads or
compensating conductors have resistance.
•
Use sufficiently thick compensating conductors.
•
Change the location of the thermocouple so that
the length of the leads or compensating
conductors can be shortened.
The resistance of the conductors for the 3
terminals is different from the resistance of the
temperature sensor connected to the E5ZE.
Use conductors that are the same in resistance
for the two B terminals and the A terminal.
Installation
Noise is affecting the E5ZE.
•
Separate the E5ZE from the source of the
noise.
•
Connect a surge absorber or noise filter to the
device generating the noise.
Inductive noise generated from power lines is
affecting the leads of a temperature sensor.
•
Separate the leads from the power lines.
•
Wire the leads in a separate conduit or duct.
•
Do not wire the leads alongside power lines.
•
Shorten the leads.
•
Shield the leads.
Thermal response of a temperature sensor
connected to the E5ZE is slow because the
temperature sensor is located far from the
temperature controlling position of the E5ZE.
Locate the tip of the protective tubing of the
temperature sensor at the temperature controlling
position.
Ambient operating temperature of the E5ZE is not
within the allowable ambient operating
temperature range of the E5ZE.
The ambient operating temperature range of the
E5ZE must be between 0
°
C and 55
°
C.
Radio transmitter is being used near the E5ZE.
Shield the E5ZE.
E5ZE is affected by heat radiation from Peripheral
Devices and the temperature of the terminal block
of the E5ZE is not even.
Install the E5ZE in a location where it will not be
affected by heat radiation.
Terminal block of the E5ZE is affected by wind.
Protect the terminal block of the E5ZE against
wind.
Temperature Sensing Errors
Section 4-3
