1、 WiringElectromagnetic flowmeter cold and heat meters

1Signal and excitation lines

1.1Signal line processing

When used in conjunction with sensors, the conductivity of the measured fluid is greater than50μS/cmIn the case of flow signal transmission cables, the model can be usedRVVPB2*0.12*280 mm 2PVC sheathed metal mesh shielded signal cable. The length of use should not exceed100mThe signal line and sensor are shipped together. This heat meter provides equipotential excitation shielding signal output voltage to reduce the influence of distributed capacitance transmitted by cables on flow signal measurement. When the measured conductivity is less than50μS/cmFor long-distance transmission, dual core double shielded signal cables with equipotential shielding can be used. for exampleSTT3200Specialized cables orBTSTriple shielded signal cable.

1.2 Excitation current line

The excitation current line can use a two core insulated rubber flexible cable, and the recommended model isRVVP2*0.12*250mm2The length of the excitation current line is multiplied by the length of the signal cable.

When usedSTT3200When using dedicated cables, the excitation cable and signal cable are combined into one.

2Instrument terminal wiring

The meanings of the markings on each wiring terminal are as follows：Table 1.1

3Output and power cord

All outputs and power cords are provided by the user according to the actual situation. But please pay attention to meeting the requirements of load current.

3.1Frequency and pulse output wiring

The frequency and pulse output of the external power supply and load are shown in the following figure. When using inductive loads, a freewheeling diode should be added as shown in the diagram.

picture1.3 External power supply connected to electronic counter

picture1.4 Internal power supply connected to electronic counter

3.2Current output wiring

picture1.5current output

3.3Within the tableOCDoor connection method

picture1.6Within the tableOCDoor connection method

3.4Grounding requirements for converter installation

The grounding terminal of the converter housing should be not less than1.6mm²Grounding copper wire is connected to the earth. The grounding resistance from the converter housing to the ground should be less than10Ω.

firstsupportΦ20Copper tube, cut into1700mmLong (can be extended as needed) made into ground nails and buried underground1500mm (note:When burying nails, sprinkle a layer of crushed wood charcoal on the nails and then water them with salt water;

nextsupport4mm²The purple copper wire is welded onto the ground nail, and finally the ground wire is connected to the sensor flange, grounding ring, and pipeline flange, as shown in Figure 1.7.

Attention: Stainless steel materials are required for fixing ground wire screws, spring washers, and flat washers.

2、 Introduction to Instrument Parameters Electromagnetic flowmeter cold and heat meters

1Traffic parameters

1.1Instrument working mode

L_MagHThere are three working modes for electromagnetic flow meters and heat meters: hot meter working mode, cold meter working mode, and cold meter hot meter mode.

Heat meter mode: Only calculates heat, which is the default mode of the instrument. “H”Expressing heat

Cold meter mode: only calculates the cooling capacity. “R”Indicate cooling capacity

Cold and hot meter modes: Both cold and hot meters are calculated and displayed separately.

1.2Measure the diameter of the pipeline

L_MagHElectromagnetic flowmeter and heat meter matching sensor diameter range:10～2000Millimeters.

10、15、20、25、32、40、50、65、80、100、125、150、200、250、300、350、400、450、500、600、700、800、900、1000、1200、1400、1600、1800、2000.

1.3Heat flow rate, cooling flow rate unit

The units for displaying instrument heat are:MJ/h、GJ/h、KWh/h、MWh/hThere are four options to choose from.

1.4Measure damping time

I.e. filtering time,Long measurement damping time can improve the stability of instrument flow display and output signal, and is suitable for measuring total accumulated pulsating flow. The short measurement damping time is manifested as fast measurement response speed, which is suitable for production process control. The setting for measuring damping time adopts a selection method.

1.5 Flow direction selection option

If the user believes that the fluid direction during debugging is not consistent with the design, they do not need to change the excitation or signal line connection

The method can be modified by setting parameters based on the flow direction.

1.6Flow zero correction

During zero point correction, it should be ensured that the sensor tube is filled with fluid and the fluid is in a static state. The zero point of flow is expressed in terms of flow velocity, measured in millimeters per second. The zero point correction of the heat meter flow rate is displayed as follows:

Upward small font display:FSRepresenting the zero point measurement value of the instrument;

Downward large font display: Flow velocity zero correction value;

equalFSDisplay not for0When adjusting, the correction value should be adjusted toFS = 0Attention: If the downward correction value is changed,FSAs the value increases, it is necessary to change the positive and negative signs of the downstream value to makeFSCan be corrected to zero.

The correction value for flow zero point is the constant value of the sensor, which should be recorded in the sensor's record sheet and sensor label. When recording, the zero point value of the sensor is the flow velocity value in mm/s, and its sign is opposite to the sign of the correction value.

1.7Small signal cut-off point

The setting of small signal cutoff points is represented by flow rate. When the small signal is cut off, only the flow rate is displayed, and the display and signal output of the cut flow rate and percentage are displayed.

1.8Removal of temperature difference signal

Temperature difference signal cutoff: When the temperature difference between the inlet and outlet is lower than this setting, the instrument does not calculate the heat and cooling capacity.

1.9Total traffic unit

The heat meter display is9Bit counter, maximum allowed count value is999999999.

The unit of total traffic usage is:m³cubic meter

The total traffic equivalent is:0.001m³、0.010m³、0.100m³、1.000m³ .

1.10Unit of total heat and cooling capacity

The heat meter display is9Bit counter, maximum allowed count value is999999999.

The unit of total heat used is:MJ、GJ、KWh、MWh.

The total heat equivalent is:0.001MJ、0.010MJ、0.100MJ、1.000MJ

0.001GJ、0.010GJ、0.100GJ、1.000GJ

0.001 KWh、0.010 KWh、0.100 KWh、1.000 KWh

0.001 MWh、0.010 MWh、0.100 MWh、1.000 MWh

be careful:KWh、MWhThe unit can only be displayed8Significant digits, cumulative maximum99999999The accumulated cooling capacity has a directional display, indicating that the accumulated amount is one digit less than the total amount of heat.

1.11Reverse measurement prohibited

L_MagHElectromagnetic flowmeter and thermal meter withReverse output prohibition function, when "prohibited", does not calculate heat and cooling, no output, only flow rate display; When "allowed", the heat meter works normally. Since in principle, reverse flow should not be used to calculate heat or cooling, all default settings are set to "prohibited"

2Output parameters

2.1Current output mode

L_MagHThere are five ways for electromagnetic flowmeter and thermal meter current output:Flow output, heat output, cooling output, cold and hot state output, flow direction output.

Flow output: The current is output as a percentage of instantaneous flow, and the percentage position displays the percentage of flow;

Heat output: The current is output as a percentage of instantaneous heat, and the percentage position displays the percentage of heat;

Cooling output: The current is output as a percentage of instantaneous cooling capacity, and the percentage position displays the percentage of cooling capacity;

Cold and hot state output: The current output represents cooling or heating, with 20mA for cooling and 4mA for heating;

Flow direction output: The current output represents the forward and reverse flow directions, with 20mA for reverse and 4mA for forward.

2.2Flow, heat, and cooling range settings

Instrument range setting refers to determining the upper limit flow value, and the lower limit flow value of the instrument is automatically set to0.

Therefore, the instrument range setting determines the instrument range, which in turn determines the correspondence between the instrument percentage display, instrument current and frequency output, flow rate, heat, and cooling capacity:

Meter percentage display value=(Flow measurement value)/Instrument range* 100 %；

Instrument current output value=(Flow measurement value)/Instrument range* 20 mA + 4mA；

Instrument frequency output value=(Flow measurement value)/Instrument range* Frequency full range value.

2.3Pulse output type

L_MagHThere are sixteen ways for electromagnetic flowmeter thermal meter pulse output:Flow pulse Ltr, flow pulse m3

Heat pulse MJ, heat pulse GJ, heat pulse KWh, cooling output MWh, cooling pulse MJ, cooling pulse GJ, cooling pulse KWh, cold and hot output MWh, cold and hot pulse MJ, cold and hot pulse GJ, cold and hot pulse KWh, cold and hot output MWh, cold and hot state output, flow direction output.

Frequency output method: The frequency output is a continuous square wave, and the frequency value corresponds to the percentage of flow rate. See details2.4；

Pulse output method: The pulse output is a rectangular wave pulse train, where each pulse represents a flow equivalent flowing through the pipeline. The pulse equivalent is determined by the "pulse output type" and the following“Set the parameters of "output pulse coefficient" in combination. The pulse output method is often used for total accumulation and is generally connected to an accumulator;

Cold and hot state output: Pulse output indicates that when in a cold or hot state, the heat is at a low level and the cooling capacity is at a high level;

Flow direction output: When the pulse output indicates the flow direction, the forward direction is at a low level and the reverse direction is at a high level.

2.4Frequency output upper limit

L_MagHElectromagnetic flowmeter thermal meter frequency corresponds to flow percentage output (not corresponding to heat and cold), with optional range1~5000The calculation formula is as follows:

Instrument frequency output value=(Flow measurement value)/Flow range* Full frequencyrangeValue;

2.5Output pulse coefficient

Pulse coefficient, also known as pulse equivalent, ranges from0.001～59.999, unit and selected pulse output type unit *, used to measure pulse output.

2.6Pulse width

Pulse output is effective at low level, pulse width:01~499.9ms

pulse widthTable 2.1: Correspondence between Degree and Maximum Number of Output Pulses