Application

The 70SP01 is a single-channel frequency input module with tandem protection relays for the BlueLine and Procontrol P13 platforms.  The 70SP01 processes raw pulses from a speed sensor measuring a toothed rotating wheel.  It uses the pulses to calculate the speed of the device being measured and then, based on user-defined criteria, outputs the speed measurement and other indications to the local bus.  

The 70SP01 offers protection for the following configurable conditions: overspeed, over-acceleration, loss of probe frequency, loss of probe signal (certain probes only), and bad power supply to the probe.  Protection is provided by two tandem 3NO/1NC safety-rated potential free relays.  The relays are operated on a de-energize-to-trip (fail-safe) principal to ensure that any failure to the system will result in a change of the contacts.  The relays are provided in tandem so that each relay may be tested individually by a 24VDC input, but when triggered by a the board monitoring circuits, both relays de-energize synchronously.  All faults self-clear after the alarm or fault condition has been cleared for a period of 10 seconds.  A maximum speed memory register is provided for turbine failure investigations.  Overspeed configuration settings are password protected for maximum safety. 

The measurement value of the card is output to any two available addresses and may be configured to any scale desired.  Typically one address is for the full range of speed, while the second address is for a zoomed range of speed.  A binary status word can be output to any available address which reports conditions such as faults, standstill, speed less than 1 RPM, overspeed, etc.