Duff-Norton SK6905-200 - Manual (Page 6)

6
6. With this set-up, potentiometer will have increasing
resistance from S to CCW (and deccreasing resis-
tance from S to CW) as the actuator extends.
2-4. Digital Position Indicator (Duff
Norton part no. SK6300-4K)
The model SK6300-4K is a highly versatile,, panel
mount, digital readout device that provides a very pre-
cise indication of actuator position. It can be
programmed to display percentage, inches, or any other
desired unit. The indicator is self calibrating wth no
need for measurements or calculations.
See the detailed instructions with the SK6300-
4K indicator for installation and programming
instructions. Potentiometer termiinal CCW should be
connected to indicator Common, CW to Excitation Volt-
age, and S to Signal Voltage Input.
Section III
Operational Precautions
3-1. D.C. Motor
This motor is a totally enclosed weather resistant, perma-
nent magnet type. This type motor is smaller, cooler
running, more efficient and has higher duty cycles than
series-wound motors. Lower current draw provides for
longer battery life. The rotation is reversible by reversing
the two color coded leads. Torque is the same in either
direction.
3-2. Voltage Supply
Avoid using a low voltage supply for the DC motor. All
wiring, switches, etc., must be of sufficient capacity to carry
the required current. (Actuator capacity may be reduced
his motor is a totally enclosed weather resistant, perma-
nent magnet type. This type motor is smaller, cooler
running, more efficient and has higher duty cycles than
series-wound motors. Lower current draw provides for
longer battery life. The rotation is reversible by reversing
the two color coded leads. Torque is the same in either
direction.his motor is a totally enclosed weather resistant,
permanent magnet type. This type motor is smaller, cooler
running, more efficient and has higher duty cycles than
series-wound motors. Lower current draw provides for
longer battery life. The rotation is reversible by reversing
the two color coded leads. Torque is the same in either
direction at low voltages.)
3-3. Clevis Pins
The axis of the clevis pins should be parallel so that the
actuator can pivot without binding. A few drops of oil should
be used on the clevis pins.
WARNING
The actuator is not recommended for use in ap-
plications where it can be jammed. Examples
of jamming include overtraveling the limit
switches and thus jamming the nut and screw
internally at the extreme ends of the stroke, and
driving the actuator against an immovable ob-
ject and thus overloading the actuator severely.
Do not operate actuator before setting limit switches. Some actuator external surface temperatures may
reach 230˚F at or near maximum allowable duty cycle.The actuator can jam a limited number of times
without damage. Therefore, consult Duff-Norton Engineering if jamming is expected.
Section IV
Maintenance
4-1. Lubrication
Duff-Norton recommends using the following lubricant in
conjunction with proper maintenance procedures of this
unit: Shell Oil Co. Darina EP2.
4-2. Required Tools
A bearing puller and press, soft jaw table clamp and com-
mon hand tools are required for proper disassembly and
assembly.
4-3. General Procedures
Duff-Norton recommends following these procedures dur-
ing disassembly and assembly:
1. Tag critical parts to facilitate reassembly.
2. Mark mating surfaces to ensure proper meshing.
3. Clean and lubricate parts as required.
4. All seals must be replaced at time of rebuild.
5. All screws, washers and other small common parts
must be replaced if mutilated in any way.
4-4. Disassembly
Disassemble the 3905, 3904, 6905 & 6904 Series DC ac-
tuator as follows while referring to Figure 5.1. Read
instructions thoroughly before disassembling.