Rosemount 644 temperature transmitter wiring's precautions

Wiring for Rosemount 644 temperature transmitter is provided free of charge

Rosemount 644 temperature transmitter is divided into single-input 644H and dual-input 644S. Instrument Mr. K introduces the wiring of temperature transmitter in this article. 

Rosemount 644 temperature transmitter wiring questions and answers

Question 1: What is the position of the four terminals in the following figure ①?

Question 2: What are the three terminals at the position ② in the figure below?

Question 3: What are the three terminals in the position ③ in the figure below?

Question 4: What is the position of the pin in the figure below ④?

Question 5: In the figure below, what do the positions of the position dials L and H represent?

Question 6: What are the two terminals at the position ⑥ in the above figure?

Combining the above figure, it is not difficult to see the role of each position of 644

Answer to question 1: The four terminals at position ① in the figure are the input signal terminals of the single-input 644H temperature transmitter;

Answers to questions 2 and 3: The terminals ② and ③ in the figure are the two input signal terminals of the dual-input 644S temperature transmitter;

Answer to question 4: The position pin in the picture is used to connect the display screen. In the field, some measuring points are equipped with a display screen, and some measuring points are not equipped with a display screen. You can open the meter cover when you are in the scene. have a look.

Answer to question 5: The position of ⑤ in the figure H and L is the failure mode position, that is, the physical hardware alarm switch is set to the required position. H means high and L means low.

Answer to question 6: the power supply terminal of the 644 temperature transmitter.

Remember this 644 temperature transmitter wiring diagram, do not worry about the temperature transmitter 644 wiring wiring:

Points for Attention in the Wiring of Temperature Transmitter 644

When wiring the thermal resistance input: The temperature transmitter can accept a variety of thermal resistance configurations, including 2-wire, 3-wire or 4-wire configuration. If the transmitter is installed far away from the 3-wire or 4-wire thermal resistance, if the resistance of each lead is up to 60 ohms, then the transmitter can work according to specifications without recalibration. In this case, the lead between the thermal resistance and the transmitter should be shielded. If only two leads are used, and two thermal resistance leads are connected in series with the sensor element, when the lead length exceeds three feet [20AWG wire, note: AWG American wire gauge, the value before AWG (such as 20AWG, 24AWG) indicates that the wire is formed at the end The number of holes to pass through before the diameter, the larger the value, the more holes the wire passes through, and the smaller the diameter of the wire], there may be obvious errors.

For 2-wire and 3-wire thermal resistance, when the ambient temperature changes, additional lead resistance errors will occur.