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3-24
IM 701210-05E
3.9
Connecting Thermocouples
Connecting Thermocouples
If you are connecting the compensation lead of the thermocouple to the input terminal
(binding post terminal) of the 701261 (UNIVERSAL), 701262 (UNIVERSAL (AAF)), or
701265 (TEMP/HPV), loosen the terminal knob, pass the lead through the terminal, and
tighten the knob.
To the thermocouple
L
H
Compensation lead (or thermocouple wire)
+ leg
– leg
CAUTION
• The 701261 (UNIVERSAL), 701262 (UNIVERSAL (AAF)), or 701265 (TEMP/
HPV) is isolated from the DL750/DL750P. However, applying a voltage
exceeding the value below may damage the input section. If the frequency is
above 1 kHz, damage may occur even when the voltage is below this value.
Maximum input voltage (across the input terminals, H and L, at a frequency
of 1 kHz or less)
42 V (DC+ACpeak)
Maximum allowable common mode voltage (across the input terminal L and
earth at a frequency of 1 kHz or less)
42 V (DC+ACpeak) (CAT I and CAT II, 30 Vrms)
• Correct measurements cannot be made if the positive and negative legs of the
thermocouple are reversed.
• Immediately after connecting the thermocouple, the heat balance may be
disturbed at the input terminal section and may cause measurement errors.
Therefore, wait about ten minutes before making a measurement.
• In an environment where the air from the air conditioning is directly applied to
the input terminals or where there are effects from a heat source, the heat
balance may be disturbed at the input terminal section and cause measurement
errors.
When making measurements in this type of environment, take preventive
measures such as changing the position.