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English
ATEX Reference Guide EL Electric actuators
DOC.ATX.EL.1 Rev.: C
February 2012
EL55 to EL 800
Pull to
declutch
Manual over-
ride
hand wheel
OPEN
(Counter
Clockwise)
CLOSE
(Clockwise)
EL1200 to EL2500
Pull to declutch
Manual
override
hand wheel
OPEN
(Counter
Clockwise)
CLOSE
(Clockwise)
Fig 3.1 Location of Limit Stops, hand wheel operation
3
Mechanical Limit stop setting
All El-series electric actuators are equipped with a
manual override feature and a Stroke Adjustment Sys-
tem. The purpose of this system is to limit the stroke of
the valve while under manual control.
On torque switch equipped actuators the limit stops
may be used to provide a greater degree of stroke pre-
cision than by limit switches. i.e.: For high performance
butterfly valves.
After the actuator has been fitted on a valve and the
end of travel limit switches have been set, the mechani-
cal stops can be set as follows:
IMpORTANT.
* For torque seated applications the mechanical stops
do not need setting in the positions that torque
seating is required and the stop screws should
be backed off approximately 2 turns from the fully
closed or open position. This to prevent the torque
switch from tripping on the stop screws and not on
the valve seat.
procedure
1 With actuator mounted to a valve, electrically or
manually move the valve away from the fully open
position.
2 Turn the open stop screw out (CCW) 4 turns.
3 Manually operate the actuator to the full open posi-
tion.
4 Now turn the open stop screw in (CW) until an ob-
struction is felt (do not force) then back off 1/2 turn
and lock the stop screw with the locknut.
5 Follow the same procedure at the closed end of
travel and adjust the “close” stop screw the same
way.
