ZPA Pečky MODACT MOA OC Instructions For Assembly Operation Download Page 6

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The torque tripping unit is also fitted with a locking mechanism. The locking mechanism locks the torque switch once

tripped and thus prevents it from re-triggering and thus also the actuator from pulsing. Apart from that the locking
mechanism prevents the torque switch, after actuator rotation reversing, from tripping, and thus enables the electric
motor’s breakaway torque to be fully utilized. The locking mechanism operates in both directions of motion of the
actuator’s output shaft, both in limit positions and in the interim position, over 1 to 2 revolutions of the output shaft, after
reversing of its motion. When the actuator’s output shaft is loaded by a restoring torque, the torque control shaft 22
rotates slightly, thus making segments 23 and 24 rotate two, which transfer the motion to tripping handle 45 or 46. As
soon as the torque on the actuator’s output shaft achieves a value, to which the torque tripping unit has been set up to,
the tripping handle will push the button of the relevant micro switch, which will disconnect the electric motor from power
supply, and the actuator will stop.

Torque unit setting procedure

To set the tripping torque to another value, differing from the default value set at the manufacturing plant,

proceed as follows: release locking nut 44

(Fig. 3),

and the relevant locking screw 25

(for “closing” direction)

or 26

(for opening direction).

Subsequently, put a screwdriver into the recess in the top segment 23 or 24 and rotate the

segment until the recess in segment 27 or 28 points at the relevant point on the scale. This point is identified by
dividing the difference between the maximum and minimum adjustable torque in Nm by the number of increments
between the maximum and minimum torque signs. This approach shows us how many Nm of tripping torque falls
on one increment on the scale. By interpolation, identify the point on the scale, to which the recess in segment 27
or 28 should point. The coloured line on the scale that is closer to number 10 indicates the setting point of
maximum tripping torque, the other line identifies the setting point of minimum torque. The torque control unit must
never be set up in a way that the recess in the bottom segment lies outside the area between the two coloured
lines on the scale.

Once the tripping torque has been set up, tighten locking screw 25 or 26 and locking nut 44.

Tripping torque must be set at a higher value than those that correspond to the individual type designation in

Table no. 1!

b) Signalling unit

(Fig. 4)

secures transmission of electric signal of the actuator input shaft’s position. The unit is driven

by gear 38 from the output shaft through the gearbox to cams 30, 31, controlling micro switches 36 and 37 37.
The switching moment of signal switches can be selected in any point of the actuator's working stroke, except
the narrow area around end positions (

signal switch must switch before the position switch while the output shaft is

still moving).

Top cam 30 operates in the

“closing”

direction and the bottom cam 31 operates in the "opening" direction.

Signalling unit is designed as a separate installation assembly. It is installed on bracket 39, below which gears are

fitted, organized according to the kinematic diagram

(Fig. 5).

The transmission is set up so that adjusting gear K3 can

be moved to various levels

(I, II, III, IV, V)

once locking screw 47 is released. By adjusting wheel K3, the setting range of

signalling switches and transmitter will change depending on the working stroke. Next to figure 6 is a table specifying
setting ranges corresponding to the various positions of adjusting gear K3.

Legend:
30 – Cams for “closing“

direction

31 – Cams for “opening“

direction

32 – Securing screws

for “closing“ direction

33 – Securing screws

for “opening“ direction

34 – Handle for “openin“

direction

35 – Handle for “closing“

direction