Brief Description; Special Features And Options; Mechanical Overload Protection; Thermal Protection - Schaeffler EWELLIX CAHB-3 Series Installation, Operation And Maintenance Manual

CA H B - 3 x s e r i e s

3.2 Brief description

The actuator has been designed and built exclusively for its
intended purpose as described in these instructions. The
authorized use of the actuator is the dynamic central push-
loaded or pull-loaded stroke. If you use the actuator for any
use other that cited, the manufacturer cannot be held the re-
sponsibility for damage resulting from this.
The linear actuator consists of an AC motor (8) (starting ca-
pacity is included), that drives a gear unit (4) and a linear unit
(1, 2, 3). The linear unit converts the rotation of the motor
and gears to a linear movement. CAHB-30 uses a lead
screw and CAHB-31 uses a high efficiency ball screw. The
gear unit uses spur gears made of metal, which leads to
long lifetime, high efficiency and high reliability. The front at-
tachment (1) and the rear attachment (6) transmit the actua-
tor power to both sides of the application.
The actuator offers a mechanical clutch and a motor thermal
switch for overload and safety protection. The stain-
less-steel extension tube, the paint coating and the engi-
neered sealing system protect the actuator from water in-
gress and corrosion. All external components of the actuator
except the cable, gland and sealings are made of metal
parts, making the actuator robust for harsh environments.
A configuration option is to have electromagnetic limit
switches that are external and can be adjusted by the user
as well as a potentiometer for position feedback. The func-
tions are referred to in the following chapter.
3.3 Special features
and options

3.3.1 Mechanical overload protection

The actuator is equipped with a mechanical overload pro-
tection unit (clutch). This overload protection is activated
when the external force acting on the linear unit is exceeded.
This activation prevents pushing or pulling beyond the maxi-
mum force defined in the data sheet and will protects the
motor and gear unit from damage.
CAUTION
Continued operation of the clutch may cause overheating and
damage to the linear actuator. If the clutch slips, disconnect
power immediately.
CAUTION
If the limit switches are configurated, the activation of the
clutch will result in position loss of limit switch. If the clutch is
activated, the position of the limit switch must be recalibrated
Contact Ewellix on how to recalibrate the position of the limit
switch.

3.3.2 Thermal protection

The thermal switch built into the motor will turn off the power
to the motor if it overheats. It automatically resets when the
temperature drops.
Overloading or frequent operation of the actuator beyond
the maximum duty cycle defined in the data sheet would
cause the motor to overheat.
CAUTION
To prevent damage from overheating, if the actuator stops with a
high motor temperature, do not restart the actuator and wait for
the actuator to cool down.

3.3.3 Option: Potentiometer

The potentiometer provides a signal that indicates the posi-
tion of the linear actuator (see chapter
ments, page 14).

3.3.4 Option: Limit switch

The limit switch makes it possible to control the stroke of the
linear unit. There is a cam connected to the motor through
gears. When the actuator runs to the end of stroke, the cam
will contact the limit switch, then cutting off the power of
motor.
It is possible to adjust the stroke by adjusting the cam angle
range. Please contact Ewellix.
7.1
7
7.2
DANGER
Danger to life caused by electric current!
Touching conductive parts causes a direct danger to life (AC
power is led with limit switches lead feet).
• Before opening the switch cover (7), switch off the power
supply and perform lockout procedures so it cannot be turned
on again.
CAUTION
Opening the switch cover (7) would damage the seal (due to the
sealant around the cover and the locking screws). If cover (7) is
removed/opened, warranty is voided.
5. Reference docu-
Figure 3
7. Cover for
protection LS
7.1 Limit switch
7.2 Cams
9