FRA251 - Frequency Alarm

Product Diagram

The FRA251 converts pulse, contact and frequency signals to a DC signal and also provides a relay contact output, and features:

  • Input from any type of frequency or pulse sensor.
  • Frequencies from 5Hz up to 5kHz.
  • Sensor excitation.
  • Front adjustments for trip setpoint and deadband.
  • Options for trip delay and external trip adjustment.
  • No isolation provided.
  • 12/24V ac/dc power supplies.

Common applications include:

  • Speed monitoring and alarm.
  • Wind speed alarm and measurement.
  • Signal conversion and local alarming.





Speed/ Frequency/ Pulse





Most drawings are supplied in PDF format. Portable Document Format is used to present documents in a manner independent of application software, hardware, and operating systems.


Lead Time for a Niche Product


Niche products are usually designed to perform less common functions and may contain made to order assemblies. Niche products have longer delivery times, typically 10 days.

Order Processing

BSI134 Additional Information Required

APCS makes and customises products according to a customers order. Upon receipt of the customers order the following information is required before manufacture, allocation or deliver until full details are given, these include;

  1. Identity of purchaser. Company name, ABN (Australian companies), street address and accounts email address.
  2. Required delivery address.
  3. Full part number and calibration detail required to manufacture items.
  4. Total on purchase order to include delivery charges. Orders received with missing information will be entered and marked to indicate missing details and returned to the customer for correction or approval.

Compliance with the above ensures that your items are manufactured and delivered according to the required specifications.

Standard delivery times commence after the order has been approved for processing.