Chapter 3 - applications, Technology principle – Rockwell Automation T6050 SurgeGard Incipient Surge-Conditioning Module User Manual

Page 35

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T6050 Operations & Maintenance Guide

Chapter 2 – Product Overview

PD-6050 Dec 04

7

1

2

3

4

5

6

7

8

250

Ohm

IN +

IN -

LOOP

PWR IN +

4-20mA

OUT

AC SIG OUT

AC COM OUT

*

*

Remove jumper
for voltage input

T

UC

VOLTAGE

TRANSMITTER

(22-32VDC)

Figure 6. Typical T6050 Field Wiring with a Voltage Transmitter

Chapter 3 - Applications


Technology Principle

When applying the incipient surge detection module – T6050 SurgeGard™ – it is important to understand the
basic technology principle…

Fluidic oscillations occur as a precursor to surge. This behavior is the result of momentary backflow at
the inlet of the impeller (the “re-circulation zone”). Since the momentary backflow is more prevalent at
the outer annulus (wall) of the re-circulation zone than at the central area, it is important that the fluidic
oscillation detection conditioning is of fast response. The speed of response must be such that it does not
obstruct the oscillation signature while allowing for low-pass filtering of the normal flow rate
oscillations.

Fluidic oscillations can be measured as: I torsional load (motor-driven), Flow/Pressure at the inlet of the
compressor or at the discharge (preferably direct at the back of the impeller casing) of the compressor.
See applications below.

In consideration of the fluidic oscillations speed in the re-circulation zone, the analog circuitry of the
T6050 SurgeGard™ is more efficient (continuous sampling rate) than the software version contained in
the T6100 and T6200 (sampling rate of 2-5 ms) and is therefore recommended for most applications.

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