K-TEK KP, Installation & Operation Manual

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KP-0200-1 Rev f (10-2010) DCN0536 11
II. OPERATION
A. Principle of Operation
Once the paddle switch is energized, the paddle will rotate at a speed of 1 RPM continuously. During
free rotation of the paddle, the switch is in a normally open state. As a result, voltage will flow be-
tween the common and normally closed terminals of the switch(es) as shown in figure 6. When the
product level reaches the paddle in a high level setup, the drag force of the product against the paddle
vanes will restrict the paddle rotation. When the paddle drag exceeds the switch spring force, the mo-
tor will counter rotate around the shaft. This counter rotation of the motor coupled to the motor bracket
will actuate the levers of the switches resulting in switch closure. During restricted rotation of the pad-
dle, the switch changes to a closed state. As a result, voltage will now flow between the common and
normally open contact. As the product level drops and the drag force on the paddle vanes is removed,
the shaft will return to its normal rotating state, allowing the motor and motor bracket to return to its
neutral position while opening the switch contacts.
Note: The hysteresis type motor is indefinitely
stalled during complete paddle stoppage but remains energized. This will not result in damage to the
motor and is normal operation for the switch assembly.
When set up for a low-level application, the presence of product around the paddle is the norm. As a
result, the motor is in a normally stalled state resulting in continuous switch closure. Once product
drops below the low-level state, the paddle rotation becomes unimpeded and the switches are
opened. Once the level returns to the normal state, the paddle is again stalled and the switches close.
B. Maintenance Requirements
The operation of the paddle switch is simple and it should operate without problems for an indefinite
amount of time. Routine maintenance requirements of the switch are minimal. Periodic checks of the
shaft alignment and free rotation within the housing should be performed. The interior of the housing
should be checked periodically to ensure there is no dust or product ingress into the motor mechanism
or switches. If product ingress is noted in harsh environments such as concrete applications, the
lower lip seal may have experienced prolonged wear.
Inspection of the motor operation should be performed semi-annually. If the motor operation appears
to be erratic or simply no longer works, a replacement motor should be obtained. Finally, the open-
closure of the lever switches should be checked annually to ensure normal operation. Replacement
switches are available in the event of a switch failure. Section III lists ordering numbers for replace-
ment parts.
Part Number Description
KPMOT120 120VAC, 50/60 Hz, Internal Assembly, includes: motor, 2 SPDT switches and bracket
KPMOT240 240VAC, 50/60 Hz, Internal Assembly, includes: motor, 2 SPDT switches and bracket
KP/P1 1-1/2” x 5” 4-Blade Replacement Paddle (25-65 lbs/ft
3
400-1040 kg/m
3
)
KP/P2 2” x 7” 4-Blade Replacement Paddle (10-25 lbs/ft
3
160-400 kg/m
3
)
KP/P3 1” x 3” Single-Blade Replacement Paddle (>65 lbs/ft
3
1040 kg/m
3
)
KP/P4 10” Diameter Insertable Replacement Curved Blade (>25 lbs/ft
3
400 kg/m
3
)
KP/CF Replacement Flexible Shaft Coupling
KP/CS Replacement Solid Shaft Coupling
KP/MP2 Replacement Side-Bin Mounting Plate with half coupling with Rubber Gasket
KP/MP4 Replacement Top-Bin Mounting Plate with full coupling with Rubber Gasket
MEC2335 1/8” Rubber Gasket for Mounting Plate
ELESWTLM-20-A 20 AMP SPDT Micro Switch
KPL2 120 VAC - Indicating Lamp (General Purpose Only)
KPL3 240 VAC - Indicating Lamp (General Purpose Only)