Instruction and Operating Manual
Overspeed Protector CTO-B45202
2019 / 02
J.M. Voith SE & Co. KG │ Division Digital Ventures
Page: 10 / 25
918 3626018864 en
D – 74564 Crailsheim
Version: 2.1
Block diagram - Overspeed Protector
Turcon
®
CTn
control
valve
trip-stop valve
reset
external trip
+24VDC
tr
ip
s
im
.
CTo
F
Mag
K
k
ac
tu
al
s
pee
d
0V
turbine
T
T P
A
mA
Fig. 2: Block diagram of the overspeed protector
3.2
Operation
A 3/2-way valve and the control magnet VRM with integrated electronics are the main
components of the overspeed protector CTO.
If no trip criteria exist, the CTO can be switched on via a reset. On doing so, relay K is
energized and thus contact k is closed. An inherently short-circuit-proof holding current
from the VRM keeps relay K energized via the closed-circuit arrangement (e.g. external
trip).
For a limited time (1.5 sec. ± 0.5 sec.), the reset actuates a maximum coil current which
generates a magnetic force FMag and adjusts the piston of the 3/2-way valve against the
progressively designed restoring spring. The coil current is then reduced and the control
piston is kept in its position. Now the supply pressure is connected with outlet A and the
trip-stop valve moves to the "OPEN" position.
In case of a trip criterion (e.g. reaching of the turbine trip frequency), the coil current in the
VRM and the magnetic force FMag become zero. The spring force FF now moves the
control piston in that position where outlet A is connected with the tank return line T.
The trip-stop valve moves into "CLOSED" position.
3.3
Trip criteria
•
Wire breakage and / or short circuit on the speed sensor (for limit value, see Chapter 1,
Electrical data, speed input)
•
Exceeding the set trip frequency
(see Chapter 9, Table 1, Adjusting values - trip
frequency)
•
Interruption of the closed-circuit arrangement (e.g. external trip) (see Fig. 2)
•
Short circuit at the holding current output (+24 V towards relay)
•
Temperature in the electronic compartment of the VRM
≥
80
°
C
Содержание 91868550
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