26231941 Crouzet USA, 26231941 Datasheet - Page 96

• Manufacturer Part Number: 26231941
• Description: CAPACITOR, MOTOR MEDIUM TORQUE CAPACITOR, MOTOR MEDIUM TORQUE
• Manufacturer: Crouzet USA

Specifications of 26231941

• Capacitance: 0.1UF
• Voltage Rating, Dc: 700V
• Capacitor Dielectric Type: POLYPROPYLENE
• Tolerance,: 10%
• Tolerance, -: 10%
• Temp, Op. Max: 85(DEGREE C)
• Temp, Op. Min: 0(DEGREE

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To produce a certain number of movements within a well defined time
period - in this case, the motor is used as a time base.
To produce a rotation movement requiring relatively low torque at
reasonable cost.
The Crouzet synchronous range consists of the following motor types :
➜ 1 Single direction
Either :
■
■
(We will see below how to ensure the correct direction of rotation).
In special applications it is possible to dispense with the anti-return totally
(SAR version). In this case, the motor may rotate in a clockwise direction.
➜ 2 Reversible
The motor rotates in either a clockwise or an anti-clockwise direction. The
direction of rotation is controlled by a capacitor.
This motor is characterised by a constant speed of rotation which is
independent of the load but linked to the supply frequency.
A synchronous motor maintains its speed of rotation until an overload
occurs.
When overload occurs, the motor loses synchronisation, ie. it stops and
develops an oscillation (vibration).
➜ Speed of rotation
This basic characteristic can be calculated as below :
Speed (in rpm) = 60 x f (en Hz)
f Hz : The frequency of the AC voltage through the coil.
P
Example :
A motor equipped with 5 pole pairs would give :
V = 60 x 50 = 600 rpm using a 50 Hz supply
and
V = 60 x 60 = 720 720 rpm using US supply (60 Hz)
Some principles of synchronous motors
Why choose a synchronous motor ?
How to select from the Crouzet range
Definition of a synchronous motor
Therefore the speed of rotation of a synchronous motor is defined
by its construction.
clockwise (CW or SA)
or anti-clockwise (ACL or SI)
: The number of pole pairs in the motor
(1 pair = 1 North Pole + 1 South Pole).
5
5
P
➜ Construction of a permanent magnet synchronous motor
Single direction
Technology
Our single direction motors are only available with a mechanical anti-
return. This assembly offers the double advantage of being a relatively
simple technical design while offering good performance.
The permanent magnet rotor has at its periphery a number of alternating
NORTH and SOUTH poles equal to the number of poles on the stator.
The latter, energised by a single coil connected to an AC supply,
produces a magnetic asymmetry which positions the rotor when stopped
in such a way that it is attracted by an oscillating torque when the current
is switched on.
This start-up condition would cause the motor to turn in either direction
if a mechanical device called an «anti-return» did not define and impose
the direction of rotation.
➜ Principle of operation
The principle assumes an electro-magnet : a permanent NS magnet
rotates around axis O in the air-gap of the electro-magnet, perpendicular
to the lines of magnetic force.
Let us suppose that this moving permanent magnet reaches the position
marked in figure 1. If the relative positions of the electro-magnet poles are
as shown in this figure, the magnet will be repelled and tend to oscillate
around an equilibrium position at 180° to direction S’ N ’ .
When the permanent magnet is just past this position (figure 2) and the
polarity of the electro-magnet is reversed, the magnet will be repelled and
return to its previous position, and so on.
Stator cover
Casing poles S.N.S.N.S.N
Cover poles N.S.N.S.N.S
Figure 1
Anti-return
Rotor
Stator casing
Induction coil
Figure 2