RIM Tach 1250

RIM Tach® 1250 Digital Tachometer

 RIM Tach 1250
RIM Tach 1250

Quick Specs...

  • Accepts shaft diameters up to 8" - ideal for crane & hoist applications
  • Non-contact design mounts directly on motor frame
  • Double C face can be sandwiched between motor and brake
  • Zero speed sensors are unaffected by grease, salt water, dirt or other
    common contaminants.

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Overview Industry/Application Specifications Related Info  

Overview / Design Principle:

The RIM Tach® 1250 is designed for 12.5 inch diameter type C face motor frames and accessory mounts. This tachometer provides precise, reliable speed signals for many monitoring and control applications and is a standard feedback device for AC & DC variable speed drives. The RIM Tach® 1250 is the process industry’s answer to a large thru-shaft option for precise speed control.

Constructed of ductile cast iron, it ensures maximum strength and endurance for possible exposure to acid wash down in pulp and paper applications. The enclosure accommodates both end-of-shaft and thru-shaft mountings and is universally machined to accommodate all sensor modules, regardless of the desired pulse count.

The RIM Tach® 1250 sensor module is engineered to provide a non-contact sensor and electronics in one interchangeable hermetically sealed package. Encapsulated surface mount electronics provide resistance to water, oil, dirt, high temperatures, shock and vibrations and overall harsh environments. The RIM Tach® 1250 can accommodate up to 2048 pulses per revolution and is bidirectional providing square wave outputs. The sensor module is very simple to change, just remove four screws and slide the new module in place.

There are no bearings to fail or requirements for flexible couplings because its magnetized drum assembly is attached directly to the shaft. The mill duty latching connectors are are easy to wire with no need to field solder or to struggle with a crimp pin.

Features and Benefits:

  • Rugged Mill Duty Construction
  • Reliable Magnetoresistive Technology
  • Easy Installation
  • Modular design for fast, easy field service.
  • Resolutions to 2048 PPR - optional Index


NorthStar’s RIM Tach® 1250 digital tachometer provides position and velocity feedback from both AC & DC electric motors, providing precise, reliable speed signals for many monitoring and control applications

Standard Operating Characteristics
Code: Incremental
Pulses per Revolution: 60-2048
Phasing Sense: A leads B for Counter-Clockwise rotation (CCW) viewing encoder-mounted end
Quadrature Phasing: 90° ± 22°
Symmetry: 180° ± 54°
Index: 270° gated to falling B edge

Input Voltage Requirement: Requirements: 5-15 Volts DC, 45 mA typical per sensor module plus line driver load
Output Signals: Line Driver, 150mA source/sink
Frequency Response: 0 - 120kHz Data & Index
Electrical Immunity: 2kV ESD, Reverse Polarity, Short Circuit
Connector: 10 pin industrial duty latching, sealed NEMA 4 &12, IP65

Shaft Speed: 5,000 RPM (J or K wheels);
3600 RPM (L wheels)
Mounting Configuration: 12.5” face mount for NEMA MG1 standards
Housing Material: Cast Iron/Stainless Steel
Acceleration Rate: 3600 rpm/sec max
Shaft Length Required: 3.0” min
Allowable Shaft End-Play: ± 0.050”
Allowable Shaft Runout: 0.003” TIR

Operating Temperature Range: -40°C to +80°C
Storage Temperature Range: -40°C to +120°C
Humidity: to 98% RH (non-condensing)
Shock (Sensor Module): 1 meter drop test, 30 G’s Min
Vibration: 18 G’s @ 5-2000 Hz spectrum

Available Specifications:

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