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Datasheets

Installation

Sizing & Wiring

*for Drawings please visit the U Series Product Page

Why should I use semiconductor strain gauge load cells as opposed to foil gauge units?

Check out our in-depth article comparing semiconductor strain gauges to foil gauges for a detailed explanation of the benefits a semiconductor gauge provides.

What is the minimum wrap angle?

Typically, the minimum recommended wrap angle around a load cell is 30-degrees, but this can vary based on material type, line speed, and web tension. For best results, the web needs to maintain continuous contact with the U Series roll. A shallow wrap angle combined with higher web speeds and low tension can allow air to be trapped between the web and the tension roll, and the signal from the load cell may be inaccurate. However, there are circumstances where a shallow wrap angle can be a benefit, particularly if the tension is very high, and may exceed load cell capacity with a greater wrap angle. It is always best to consult a Montalvo Applications Specialist to ensure best results.

Can I use these in “Hazardous Areas”?

Yes, the U Series Load Cells can be used in a hazardous area, provided they are connected to the appropriate barrier blocks to limit the current in the affected area. Montalvo offers a Series of barrier blocks approved for use in Class 1 Division 1 Hazardous Areas. Please consult a Montalvo Applications Specialist for assistance with these applications.

Can these be washed down?

The U Series load cells are suitable for use in an area that requires wash-down procedures. They are rated IP67, which indicates that they are dust tight, and protected from complete immersion in water. They have also been tested against damage from caustics and acids.

Can they be used in “Clean Room Environments”?

The U Series load cells are perfectly appropriate for use in clean-room environments as the bearing areas are sealed, and they emit no dust or fumes.

Are these drop in replacements for “Brand X”?

The U Series load cells utilize a Montalvo-specific mounting pattern, and therefore are most likely not “drop-in” replacements for other load cells. We do, however, drill and tap the top plates of the load cells to accept your specific pillow-block bearing to facilitate installation. Adapter plates can also be provided which can match existing bolt patterns.

Will these load cells work with “Brand X” Controllers/Amplifiers?

The U Series load cells require 5 volts of DC excitation, and provide an output from 0-250mV. They may be used with any amplifier that meets these requirements, but it is recommended that they be used with a Montalvo amplifier to ensure proper function. Please consult a Montalvo Applications Specialist if you have any questions regarding proper amplification.

Are these load cells intrinsically safe?

On its own, the U Series load cell is not intrinsically safe. The load cell must be connected to the appropriate Barrier Block system, approved for the proposed load cell location. Please contact a Montalvo Applications Specialist for assistance with these applications.

What excitation voltage do these load cells use?

The U Series load cells require 5 VDC excitation.

What is the maximum tension I can measure?

The maximum measureable tension for U-Series Load Cells is 67,440 lbs (300,000 N)

What is the lowest/lightest tension I can control to?

Montalvo U Series load cells can repeatedly and accurately measure and control to less than 2% of maximum stated load.

Can I drill the U Series for my pillow block bearing?

It is not recommended that customers drill the U Series top plates. There is a risk of damaging the sensing components of the load cells if not drilled properly. Montalvo recommends providing the factory with the pillow block bearing make and model, or the mounting hole dimensions, and Montalvo will drill the top plates to your specifications at no additional charge.

Can I mount this load cell vertically?

Yes, the U Series load cells can be mounted vertically. Please consult the sizing calculations or consult a Montalvo Applications Specialist for assistance with proper sizing and mounting orientation requirements.

Can I mount this load cell upside down?

Yes, the U Series load cells can be mounted upside down. Please consult the sizing calculations or consult a Montalvo Applications Specialist for assistance with proper sizing and mounting orientation requirements.

I have a faulty UPB (old style). Can I replace it with a U-Series?

Yes, UPB load cells can be replaced with the U-Series load cell. A base plate adapter is required (available from Montalvo), and the existing UPB top plate must be re-used.

Can I purchase adapter plates?

Yes. Both top and bottom plates are available to ensure that the U-Series load cells drop in as replacements for the UPB load cells, and maintain existing bearing height for proper alignment.

How do I calibrate my U-Series Load Cell?

The calibration procedure for the U Series load cell is the same as for just about any other load cell. Typically the load cell amplifier circuit is zeroed, with no load on the load cell at all, then a known calibration weight is suspended from a rope or a strap, following the typical web path. Then the amplifier circuit is adjusted to provide the appropriate output for the given calibration weight. It is recommended that a calibration weight that represents at least 25% of maximum web tension is used. If the U Series load cell is used in conjunction with the Montalvo A4 Digital Load Cell Amplifier, simple push-button calibration can be performed using 10% of the load cell load rating for the calibration weight. Please refer to the calibration procedures for either the M-32XX Series of Montalvo Load Cell Amplifiers or the A4 Digital Amplifier for more details.

How do I test resistance?

The U Series load cells utilize Strain Gage technology in order to sense the web tension and tension changes. In the rare event that the load cell signal is in question, it is possible to measure the gage resistance to make sure it is in the correct range for proper operation. The gages are rated for a nominal resistance under no load at 90 to 120 ohms. To check the gage resistance, disconnect the load cell cable from the amplifier/controller. Typical load cell cable color codes are as follows:
Black: negative load cell excitation
Red/Brown: positive load cell excitation
White: load cell signal
With an Ohm Meter, measure the resistance between Black and White wires – should be between 90-120 ohms; between Red/Brown and White wires – should be between 90-120 ohms. If the difference between the two readings is greater than 5 ohms, this could indicate a problem with the load cell beam. Please consult the factory for additional information.

How do I invert the load cell signal?

The load cell signal can be inverted at the load cell amplifier/controller by swapping the white wires at their respective input terminals.

How do I test operation?

Provided the calibration has been successfully completed, testing the load cell function can be done by having someone push on the load cell idler roll in the direction of force due to web tension, and monitor the tension change. Alternatively, you could use the web to apply a force to the load cell, and monitor the output change from the amplifier.

How do I change my load cell connector from 6 pin to 4 pin?

We advise that you Contact Us to go over the details of how to rewire your connector to 4 pin from 6 pin to ensure proper connections.