Speed Measurement; Fig. 15: Functional Principle - ABB PT004165 Operation Manual

Operation Manual / Power2 850-M / High-pressure stage
5 Monitoring during operation / 5.3 Speed measurement
5.3

Speed measurement

5.3.1 Introduction
Speed measurement systems enable the constant monitoring of the speeds of the low-pres-
sure and the high-pressure stage.
5.3.2 Layout and function
Fig. 15: Functional principle
01 Speed sensor
02 Cable
03 Casing flange
04 Electronics
05 Cable
06 Plug
The speed measurement system consists of a sensor (01) with integrated cables (02, 05), an
electronic unit (04) and a plug (06). The sensor operates according to the eddy current prin-
ciple, and is installed in a radial direction in relation to the compressor wheel. The electron-
ics must be provided with a power supply, and deliver a square pulse signal. The signal fre-
quency depends on the number of main blades on the compressor wheel. The signal amp-
litude depends on the level of the feed voltage.
CAUTION
Do not put the speed measurement cables under strain by pulling them
If you pull the speed measurement cables too hard, contacts can be pulled
out.
Do not strain the speed measurement cables by pulling.
u
© Copyright 2022 ABB. All rights reserved. HZTL4063_EN Rev.F March 2022