MNM MS-1-20K Replacement Guide: Matching a 20,000 lb 3 mV/V S-Type Load Cell
- pete8781
- Jul 29
- 2 min read
Need help matching a replacement sensor? Call MNM Scales at (832) 290-3120 or email mnmscales@yahoo.com with the old load-cell model and photos of the installation.
Replacing a 20,000 lb S-type load cell is not as simple as matching capacity. The MNM MS-1-20K is a 3 mV/V-class, 350-ohm-output-bridge sensor, but a true replacement also needs compatible mechanical dimensions, thread size, loading direction, cable/connector arrangement and indicator calibration.
1. Match Capacity and Load Direction
The replacement must support the intended maximum force with appropriate engineering margin. If the original system uses tension and compression, confirm that the replacement geometry and mounting are suitable for both directions.
2. Match Electrical Characteristics
MS-1-20K published values include 3.00 ± 0.01 mV/V rated output, 385 ± 15 ohm input resistance and 350 ± 5 ohm output resistance. A different nominal sensitivity can often be calibrated by a capable indicator, but compatibility should be confirmed before purchase. Bridge resistance also affects how many cells an indicator can drive.
3. Match Mechanical Dimensions and Threads
Compare overall height, width, thread diameter/pitch, shoulder clearances and cable exit location. MNM’s public product page does not publish all mechanical dimensions, so do not assume another 20,000 lb S-beam is a drop-in replacement based on capacity alone. Measure the existing cell or request a drawing when fit is critical.
4. Check Wiring and Connector
The MNM color code is red +excitation, black -excitation, green +signal and white -signal. If the old cell uses a plug, connector pinout must also match or be rewired correctly. Never match solely by wire color across different brands.
5. Recalibrate the Complete System
After replacement, establish zero and perform known-load span calibration with the actual indicator and fixture. Then verify several points. A replacement that is electrically compatible but not recalibrated can still produce incorrect displayed force.
FAQ
Can any 20,000 lb S-beam replace the MS-1-20K?
No. Capacity is only one requirement. Electrical output, bridge resistance, dimensions, threads, environmental rating and indicator compatibility also matter.
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