FAQ s on Siemens Magmeters

Transcription

1 FAQ s on Siemens Magmeters 1. The cables for the coils and electrodes for the magmeters look the same. Does it matter which cable is used for coils and which one is used for the electrodes? Both cables are the same outside diameter. When they are cut back, both have an overall braided shield. The heavier gage wire is used for the coils, and only 2 of the three conductors are used. The lighter gage wire is used for the electrodes, and all three conductors are used. As each of the three electrode wires are revealed, cut into them and you will find that each wire again has its own shield and another center conductor. The wires for the coils and electrodes from the mag body are terminated in black molded plugs with the correct conductor number corresponding to each pin of the plug. 2. Can the electode cable and the coil cable run in the same conduit in a remote transmitter configuration? It is suggested that 1 standard cable be used for the coils and one special double shielded cable is used for the electrodes. In this case, both cable can run in the same conduit from the mag body to the remote transmitter. If two standard cables are used without the double shielding for the electrode connection, the empty pipe detection capability is gone and separate conduits are suggested. 3. What do I do with the Shields? The overall braids of the both cables are tied to ground in the termination chamber of the mag body. When you get to the transmitter end, ONLY THE COIL CABLE (LARGER GAGE WIRE) has the shield tied to ground, while the overall braid of the electrode cable (lighter gage wire) is cut off and taped, not grounded. The shields of the three individual conductors of the electrode cable are tied on both ends, with the 0 terminal having both the conductor and shield under the same terminal.

2 4. How long can the cables be from the mag body to the transmitter for a remote transmitter, and can they be spliced? The length of the cable is determined by the conductivity of the fluid being measured. The higher the conductivity, the longer the allowable cable length, up to 600ft and more for most conductive fluids. The MagFlo Handbook includes a conductivity vs. cable length chart. Splices are discouraged to avoid moisture ingress. Both cables may be run in the same conduit. 5. Where is the SensorProm to be located? The SENSORPROM is shipped in the housing on top of the mag body. If it is to be an integral mounted transmitter, the SENSORPROM stays in the mag termination chamber. If the transmitter is to be remote, the SENSORPROM MUST BE MOVED. The SENSORPROM must be located wherever you mount your transmitter. 6. When the meter is turned on, flow readings are present but I have no ma output. The 4 20mA output of the magmeter is default as off. It must be turned on as it is one of the many variables that are monitored, and will be flagged as an error if loop continuity is not detected. The 4 20mA signal is sourced and will drive up to 800 ohms, with selection of unidirectional or bidirectional. Unidirectional will only detect forward flow, and will stay at 4mA when a negative flow value appears. Another cause for a ma output to stay at 4ma even with a flowrate present in that a 5000 series transmitter may have been purchased with built in HART, or the 6000 series with an add on Hart module. To operate with Hart in the ma output mode, the HART address must be set to 00. With a HART address of 01 thru 15, the ma output will stay at 4mA and expect to communicate the process data digitally over a multi drop HART wiring configuration.

3 7. A rate of flow value is shown, but my totalizer does not register. There are two totalizers available on the 5000 and 6000 series transmitters. Each totalizer acts independently of the other and may be set for forward flow, reverse flow, or net flow, where forward flow adds to the total, and reverse flow subtracts. If a totalizer is set for negative flow and forward flow occurs, the totalizer will appear to be not operating. The totalizer may be assigned to a scaled pulse with a programmable on time duration, or to the relay. 8. The flowmeter shows rate and total, but it appears to be reading invalid flow values, and will not allow me to configure a full scale value any higher than a flow value much lower than my line size dictates I should be able to read. Each meter is shipped with a SENSORPROM with the information as to the size and calibration factors for a specific body. If the SENSORPROM is not seated properly to allow the transmitter to read it, or if in a remote configuration the SENSORPROM was not moved from the mag body to be located with its now remote transmitter, the meter will default to a 2 meter, that has a max flow around 300 to 400 GPM. It is a good practice to check to make sure the transmitter is making good connection with, and is able to read the SENSORPROM. In the configuration menu go to SENSORPROM and an installed or not present indication will be displayed. Make sure the SENSORPROM is there, and reseat it to the wiring termination board. 9. The display show a flashing box with a diagonal line, and I am getting a P40 error code to replace my SENSORPROM The SENSORPROM could get corrupted by removing the transmitter with power on or from unclean power to the transmitter, either due to power surges or harmonics on the AC line of the primary power. The nameplate information is needed and your local Gilson office should be contacted to get a quote on a new SENSORPROM specific to your mag body.

4 To get by, even with the SENSORPROM not read, you can enter the configuration mode and manually program the meter size. This value is programmed in METERS. From the nameplate on the side of the meter body junction box get the DN number that states the size in mm. Take the DN number and simply divide by 1000 to get what you need so a 2 meter = DN50. DN50 / 1000 = size of METERS. When the meter starts up, it looks for the SENSORPROM. When it doesn t read a valid data set, it goes to the transmitters default. The above step is reprogramming the transmitters DEFAULT to your actual size. Do get the new SENSORPROM ordered and installed to keep the interchangeability of transmitters without the need to reprogram, and maintain the ability to perform a re verification of accuracy with the Siemens VERIFICATOR by comparing present mag body parameters to those when the meter was first built as stored on the valid SENSORPROM. 10. Can the transmitter be removed with power on the unit? The transmitters do have short circuit protection so the coil driver will not blow if removed with power on, although removing the transmitter with power on is not recommended as it may result in corruption of the SENSORPROM should this occur during a period when data is being written to the chip. 11. The meter is installed reading accurate rate and total, but shows an overflow error. The transmitter offers a 4 20mA output for remote rate, but has multiple outputs like scaled pulse, relay, or frequency for remote totalization. Any outputs not being used should be turned off in the configuration to avoid having to make sure the important parameters being used are not causing the additional outputs to go into overflow, or exceed their configured output response.

5 12. The transmitter was ordered with HART, but I cannot communicate with the meter. The device being used to communicate HART (HART Handheld or a Laptop with a HART Modem and a configuration software package like Siemens PDM) first must have the correct Device Descriptor and the loop must have between 250 and 1100 ohms to allow HART communications. As far as the transmitters are concerned, the 5000 Series is purchased with or without HART, while the 6000 Series has an add on module that is plugged into a socket on the bottom of the transmitter. The 5000 has the same molded body as the 6000 but will not read the add on module. In addition to having HART, two wiring jumpers must be added to the wiring board as indicated by a decal on the module or on the bottom of the 5000 HART transmitter, shorting terminal 31 to 91, and 32 to 92. Terminal 31 if the positive current connection while 32 is the negative current output connection. The HART capability is wired into the loop in parallel. You are not creating a parallel current path, but allowing the HART frequency to be read off the loop. Any other components in your loop must be wired in series as with all current sensing devices. 13. I have configured my meter and it reads and totalizes accurately, but the 4 20mA output is locked at 4mA, and cannot even be forced in the maintenance section of the configuration menu. When a transmitter has HART, it can be set to operate in a ma output mode where HART is used primarily for configuration, or it can be set to operate in HART Digital Mode. This is determined by the HART address. If the address is set to 0, the transmitter will allow current output to fluctuate with the process variable, or to be forced in diagnostics. If the address is set to 01 thru 15, the transmitter is looking to communicate digitally over HART and will lock the current output to 4 ma in both operational mode as well as in diagnostic mode.

6 14. There is a directional arrow on the neck of the meter body, and it is opposite of my actual direction of flow. Does the meter have to be removed and turned around? The arrow actually indicated the direction the unit was tested at the factory. After the unit is installed and wired, there is a 50/50 chance you will have a negative flow value, which can also make a forward flow totalizer not register. In the Configuration menu under Basic Settings is a selection to reverse the direction the meter recognizes as forward flow, so the meter does not have to be removed and turned around. 15. I have the meter installed properly but it shows 0 or zero flow?? Open the termination box on the sensor (mag tube), either integral or remote transmitter configuration, and check to see that the electrode connector is plugged into corresponding terminals , on the termination strip. The black molded connector has the proper terminal numbers molded into the plug across from the corresponding pin. In a remote transmitter configuration make sure that the cables for the electrodes (lighter gage wire with individual shields) have their center conductors wired to the terminals directly across from the corresponding pin number and that the shield is not tied to an incorrect terminal. Also for remote configurations, make sure that the conductors follow the same color from the terminal strip in the mag body the same corresponding terminal at the remote transmitter. 16. F70 Coil resistance Error F70 indicates Coil Excitation has failed. Check your electrical connections on both the transmitter and mag body end. Another source of this error is an incorrect coil excitation frequency. Go to point to the Siemens magmeter in Gilson Flow Lab pictures on the homepage and you can download or view the instruction manual that lists the various mag body models for the correct drive frequency. Be careful as two values are stated, one for 50Hz and a different for 60Hz. Settings can be changed by entering the program menu and going to Sensor characteristics. If this does

7 not eliminate the error, then remove power and check the resistance from 85 gnd And 86 gnd. Resistance should be greater than 10 meg ohms. If less than 10 megohms, then check wiring. Also check resistance of the coil. This resistance should be in the range of ohms. 17. My flow reading is half of what it should be. One of the two electrode circuits is not functioning. Check the electrode circuits for shorts to ground (82 to ground and 83 to ground), open circuits along electrode cable in remote mount installations, and continuity with actual electrodes inside meter body (82 to one electrode inside meter tube, 83 to other electrode inside meter tube). The Verificator cannot discern between short circuits to ground on the electrodes and a meter filled with a conductive liquid. 18. The display seems dim or flickers. A dim or flickering display can be the result of the display board connector that mates to the main board of the transmitter working its way loose during shipment. Remove the bezel around the display and the screws holding the display board in place will be revealed. Remove the screws and lift the display to gain access to the interconnecting cable. Reseat the cable connection to the main board and replace the display board in the desired orientation ( may be rotated in 90 degree increments) and snap the bezel cover back in place. 19. What is empty pipe detection? (Read this if you potentially have a pipe that s not all the way full with fluid OR if you are getting a flow reading when you know the meter doesn t even have fluid in it) Empty pipe detection is an available feature only if you are using the special double shielded cable and the standard coil cable for remote wiring (feature not available when using 2 standard coil cables). When this feature is turned on, the meter will read 0 gpm until the monitoring electrodes are satisfied. The sensing electrode for this feature is at the top

8 of the pipe (at 12 o clock) on the 5100W, and this electrode must be covered by the fluid before a reading occurs. Therefore, you will not get a flow reading if your pipe is partially full, and you will not get the floating associated electrodes in air. This feature can be turned on/off in the programming. This feature is not only helpful in detecting an empty or partially full pipe but also in eliminating outside EMI/RFI interferences. 20. Why does my totalizer read #####? The totalizers each have a limit of 8 digits. You will want to double check where your decimal points are when programming. This ##### symbol means that you have gone over the 8 digit limit (i.e. 99,999,999). To display the totalizer again, you must do one of two things: 1) Reset the totalizer back to zero and start over. 2) Increase the units to accommodate the total flow (for example, 99,999,999 gallons should be increased to 99 million gallons) 21. Is the Siemens Magmeter secured for billing purposes? The Siemens Magmeter Transmitters, model 5000 or 6000, have a Configuration Menu that is password protected, and an Operator Menu that is not protected. The user can in the Configuration Menu define which of the possible 20 menu items that will be accessible to the operator, or unprotected by password including resetting of the local totalizers. Even when password protected, there is a back door entry to reset the password to the factory default This may not be acceptable when used for billing purposes as in a municipality accepting the magmeter for billing purposes. Both the 5000 and 6000 transmitters are available in the CT version, short for Custody Transfer, meaning suitably secure for billing. These units include solder pads on both sides of the termination board and a jumper key. When the key is in place, all configurable parameters may be changed. When the key is removed, all configurable parameters, including resets, are locked in place. Many municipalities will still require the securing wire rope

9 and Lead crimp. To accommodate this need, the transmitter enclosure base for both the integral and remote transmitter configurations have eyelets for the wires securing the transmitters in place by the monitoring authority. 22. I just installed my new magmeter in finished water exiting the plant and the reported flow is all over the place. The flow I expect to be 1000 gpm bounces from 1000 to 300 to 250 to 750, drifting all over the place After looking making sure all electrical cabling is away from electrical interferences on the power cables, the output cables and the sensors cables for coils and electrodes, and that all shielded cables are terminated correctly, look for a chemical addition point upstream of the flow meter inlet. Chemical addition, like Sodium Hypochlorite addition in finished water can create wild swings in conductivity of the overall fluid making it appear the magmeter is drifting. The effects can vary based upon the chemical. To be safe keep all chemical addition points downstream of the mag body. 23. My magmeter reads half flow, and I have checked the unit is set for the proper frequency (60 hz in USA), checked my coil drive frequency, and checked everything else but continue to get a crazy low reading. Double check all coil and electrode connections, especially in a remote transmitter configuration. With the clamp down style terminals, make sure that a sufficient amount of insulation has been stripped so you have a good electrical connection, at all junction point, in the mag body, as well as at the transmitter. It is easy to overlook that either a wire was not stripped far enough back leaving the terminals to clamp on insulation, or that a screw was not tightened leaving a loose conductor. 24. I have a 6000i transmitter in a metal enclosure. I have powered the mag transmitter with 120VAC as ordered, but I am getting no 4 20mA output. Like the 5000 and 6000 series compact versions in the plastic housings, the

10 4 20mA output must be turned on in the configuration menu. On the 6000i, another step may be required as the 4 20mA is standard as a sinking output. A jumper must be changed to source the 4 20 (drive the 4 20 with the internal 24VDC supply). Only the 6000i transmitter offers a field selection of sink or source. The compact 5000 and 6000 transmitters in the plastic housing only source, no sinking. 25. I have the magmeter installed and configured. Can I simulate the outputs to check my control system? Outputs can be simulated without the need for flow. Go into the Configuration menu, and scroll across to the Service Menu. Under the current output, you can select NORMAL with the current output tracking the current flow, or FORCED. With FORCED selected, you get a prompt to enter the desired forced current output. Under Digital output, If you have the digital output configured for a frequency output, change the setting from NORMAL to FORCED and you will get a prompt for the desired frequency to simulate. If the digital output is configured for any output other than frequence, like totalizer output, error detect, flow direction, flow limit, etc, you will get a prompt to drive HIGH or LOW. Under Relay Output, you can select ON or OFF. Keep in mind the relay output cannot be tied to the totalizer output. Only diagnostics, Flow Direction, or a Flow Rate Alarm.

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