KSB EA-C, Installation & Operating Manual, Page: 22 / 44

5 Reassembly
22 of 44
EA-C
Fitting of optional limit switches for continuous actuation
ü
The power supply has been disconnected.
ü The actuator has been secured against unauthorised start-up.
ü The coupling has been fully extended using the handwheel.
ü
The operating manual for the limit switches included in the scope of supply is on
hand.
1. Open the actuator cover. ( ð Section 5.4, Page 16)
2. For all other steps, see the operating manual supplied.
NOTE
For straight-way valves, first set the CLOSED position force-dependent / stroke
dependent, then set the OPEN position stroke-dependent.
1. Use the handwheel to move the actuator into the limit position until the valve
disc touches the valve seat.
ð The position is reached when the valve stem starts to move axially against
the disc spring force in the stem nut.
2. Continue to operate the actuator until the disc springs are slightly pre-
compressed (approx. 1.5 mm).
3. Loosen the locking screw of the corresponding switching cam.
4. Turn the gear screw to move the switching cam towards the limit switch until
you hear the limit switch click.
5. Tighten the locking screw.
6. Check the setting by repeating the closing action electrically.
ð
If the setting for the position is too low, the slip coupling will start making a
rattling noise. Re-adjust the cam as required.
7. On the basis of the lower limit position, read the required stroke on the scale to
set the OPEN position. Set the limit switch to this position.
8. Set the 2 volt-free changeover contacts so that they switch slightly before the
standard switches.