Nexen SW100 803354 - Manual (Page 4)

4 FORM NO. L-20361-E-0713
Critical roll speed = 4.8 x 10 6 x Shaft O.D.
(in RPM) (Shaft Length) 2
All dimensions are in inches.
To assure this problem is avoided, the critical roll speed
should at least be 20% above the roll speed attained at
maximum web speed.
GENERAL INFORMATION
RECEIVING AND UNPACKING
Handle and unpack the equipment carefully. Upon arrival,
check the shipment against the packing list. Any damage
should be reported immediately to the carrier and to your
authorized Nexen Web Handling Distributor. Equipment which will not be installed immediately should
be stored in a clean, dry location. Precautions should be
taken to prevent moisture, dust, and dirt from accumulating
in storage and installation areas.
PRECAUTIONS
Shipping and Handling
The Tension Sensor must be removed when a machine
is shipped.
Roll Balance and Critical Roll Speed
The sensing roll must be dynamically balanced when the
roll speed is 300 RPM or greater. The sensing roll must
not be driven or have any force applied to it other than by
the web. Excessive vibrations can damage the sensors.
Even with a balanced roll, a vibration can be set up in a
stationary shaft. If this vibration (in cycles per minute)
occurs at the harmonic frequency of the shaft, the Tension
Sensors can be damaged. To determine the critical roll
speed, use the following formula:
Overloading
Repetitive overloading above the maximum force, shock,
or severe overloading should be avoided because it will
damage the sensors.
SPECIFICATIONS
Gage Resistance
95 ohms per gage nominal
Excitation Voltage
6.0 VDC or VAC (RMS) maximum
Output Signal at Rated Maximum Force
250mV nominal per Tension Sensor (1/2 bridge)
500mV nominal per Tension Sensor pair (full bridge)
The Tension Sensor must be completely surrounded by a
soft foam cushion when being transported.
Required Input Impedance of Tension Amplifier
5 K ohms per Tension Sensor (1/2 bridge)
10 K ohms per pair (full bridge)
Operating Temperature
0
o F to 200 o F, (-18 o C to 93 o C)