LMI Excel XR Digital Metering Pump: VFD Drive, Output Codes and Fieldbus Control
Say "LMI" and most people picture a yellow solenoid pump. The LMI Excel XR is a different animal: a motor-driven mechanical diaphragm metering pump that sets flow by changing motor speed through variable-frequency drive technology, and it is built around turndown and communication. This guide walks through the LMI Excel XR model code, its flow and pressure sizes, the three control modes and the liquid ends, and points out where orders usually go wrong.
The headline performance figures first: turndown up to 1000:1, steady-state accuracy of ±1.0%, repeatability and linearity both ±3.0%, rated for continuous duty. Power input is universal, 100–240V at 50/60 Hz, and the enclosure is NEMA 4X/IP65.
What the VFD Drive in the LMI Excel XR Does
Most motor-driven diaphragm pumps adjust flow mainly through stroke length. The LMI Excel XR changes motor speed instead; the data sheet describes it as flow control through variable motor speed. Because speed can be turned down a long way, turndown reaches 1000:1 and you don't have to crank the stroke very short to get a small dose.
It can also change the stroke profile, varying discharge speed while keeping suction speed constant. There is a slow-suction mode for viscous and off-gassing chemicals, and every model carries StayPrime degassing technology. These functions come in all three modes, so there is nothing extra to order.
LMI Excel XR Output Codes: Six Flow and Pressure Sizes
There are two drive ends, XRD and XRE, and the last digit of the drive code is the output code:
- XRD 2: 21.2 L/h, 12 bar;
- XRD 3: 53.0 L/h, 5 bar;
- XRD 4: 68.1 L/h, 3.5 bar;
- XRE 2: 60.6 L/h, 10.3 bar;
- XRE 3: 121.1 L/h, 6.9 bar;
- XRE 4: 200.6 L/h, 4.1 bar.
At the same output code, the XRE gives roughly three times the XRD flow at slightly lower pressure. If you need 12 bar and only twenty-odd liters an hour, XRD 2 fits best. If you need over a hundred liters at moderate pressure, look at XRE 3 or XRE 4.
How the Model Number Is Built
A full LMI Excel XR part number has four blocks: drive end, power code, liquid end and connection kit, for example XRD12 1 A44AC A7T1. In the drive end, the character just before the output code is the control mode: 1 is manual, 9 is enhanced, P is Profibus communication and M is Modbus communication. Power code 1 is 110–120 VAC with a US plug, 3 is 220–240 VAC with a DIN plug, and codes 2, 5 and 6 cover other plug types. Pick the code that matches your site voltage and confirm the plug style locally.
Three Control Modes, and Where People Go Wrong
This is the part of an LMI Excel XR order that most often goes wrong.
Manual mode only lets you set flow from the panel. It has a single digital input for a single-point level switch or remote start/stop, no analog input and no outputs at all.
Enhanced mode adds 0/4–20 mA analog control, pulse control, batch dosing, a cycle timer and timed events. Digital inputs grow to four, covering a two-point low-level switch, pulse input and remote internal/external selection. There are two analog inputs, one of which can read tank level, plus two programmable digital outputs, one 4–20 mA flow output and a 24V supply for something like a flow sensor.
Communication mode builds on enhanced mode with two-way Modbus RTU or Profibus DP. Note that the protocol has to be chosen when you order. Profibus and Modbus are different drive-end part numbers, and you can't swap one for the other with a settings change after delivery.
Don't Forget the Cables
The data sheet states that customers may need extra cables from the accessory list to connect the inputs and outputs they plan to use. Enhanced models ship with a 4-pin cord set, and communication models add a 5-pin one. If you plan to use digital or analog outputs, you may need additional 5-pin and 6-pin cables. Discovering at wiring time that a cable is missing is the single most common hiccup we see. So list every input and output you intend to use, check it against the accessory table and order the cables together, including extension leads, which come in several lengths.
Liquid Ends and Turndown on the LMI Excel XR
Liquid ends come in PP, PVDF and 316L stainless steel, plus slurry and high-viscosity versions. The slurry head pairs 316L with 440C balls. The high-viscosity head is limited to 150 psi (10.3 bar) when fitted with PE tubing.
One detail that is easy to miss: 1000:1 isn't available with every combination. The A74TC liquid end on the smaller sizes tops out at 200:1. On XRD 4, XRE 3 and XRE 4, the standard PP and PVDF heads reach 500:1; on those three sizes, 1000:1 needs a metal, slurry or high-viscosity head. If turndown is the reason you are buying an LMI Excel XR, check the liquid end against the table.
Where an LMI Digital Metering Pump Like This Fits
The data sheet lists water treatment, wastewater, chemical processing, oil and gas, power generation, pulp and paper and textiles among its uses. In our experience three kinds of project suit it best: plants where inflow swings widely and a wide turndown is needed; systems where a DCS or PLC sends set points over a fieldbus; and sites whose operators prefer a Chinese-language menu. The multilingual menu covers English, French, Spanish, Portuguese and Chinese, which makes commissioning and handover easier.
If you only need fixed dosing and manual adjustment, the communication features of an LMI digital metering pump go unused, and a standard mechanical diaphragm pump or a solenoid pump may make more sense. NEWDOSE also offers solenoid and mechanical pumps with external control that can be compared against the same duty.
Conclusion
The LMI Excel XR comes down to three checks. Flow and pressure: pick from the six XRD and XRE output codes. Control: choose manual, enhanced or communication mode, and fix the fieldbus protocol at order time. Turndown: check the liquid end, since some plastic head combinations don't reach 1000:1. Get injection pressure, flow range, control signals and chemical together before matching a model, and you are unlikely to order the wrong pump.
FAQ
Is the LMI Excel XR a solenoid pump?
No. It is a motor-driven mechanical diaphragm metering pump that adjusts flow through motor speed, a different design from LMI's P+ and C series solenoid pumps.
Can I upgrade a manual LMI Excel XR to communication later?
We wouldn't plan on it. The control mode is part of the drive-end part number, and Profibus and Modbus are separate models, so decide at the selection stage.
Does the LMI Excel XR accept 4–20 mA?
Enhanced and communication modes accept 0/4–20 mA analog control and can also output a 4–20 mA flow signal. Manual mode cannot.
Can it handle off-gassing chemicals like sodium hypochlorite?
It is worth considering. Every LMI Excel XR has StayPrime degassing plus a slow-suction mode for off-gassing fluids. Check the liquid end material against the chemical concentration.
Is the LMI Excel XR display available in Chinese?
Yes. The multilingual menu includes English, French, Spanish, Portuguese and Chinese, shown on a four-color backlit display.
Want to check that an output code and control mode match your system? Send us your duty through our contact page and we will confirm the model and cable list with you.