Vilter VSM 71-701, Operation And Service Manual

Page: 187 / 244

9
FAST HEAT, INC.
STANDARD
CARTRIDGE HEATERS
SPECIFICATIONS
Wattage Tolerances: +5% – 10% based on
Nema standards.
Resistance Tolerances: +10% – 5% to give
above power tolerances. Note that above
tolerances are based on internal operating
temperature since the room temperature
resistance of an element wire is normally
8.5% lower than when operating.
Standard voltages are 120V or 240V. 120V
max. for short length units
3
/
16
”, 1 /
4
”, and
5
/
16
” dia. (4.7, 6.3, 7.9 mm).
SPECIAL NOTE ON WARRANTY
Heaters with an operating voltage higher
than 250 Volts must be larger than or
equal to 5/8” diameter to be eligible for
a warranty.
DIAMETER TOLERANCE
ENGLISH SIZES METRIC EQUIVALENT
3 /
16
” (0.1875) = .183 ± .001 4.6 mm ± .02
1 /
4
” (0.250) = .245 ± .002 6.3 mm ± .05
5 /
16
” (0.312) = .308 ± .002 7.8 mm ± .05
3 /
8
” (0.375) = .370 ± .002 9.4 mm ± .05
7 /
16
” (0.437) = .432 ± .002 11.0 mm ± .05
1 /
2
” (0.500) = .494 ± .003 12.6 mm ± .07
9
/
16
” (0.562) = .562 ± .003 14.3 mm ± .07
5
/
8
” (0.625) = .620 ± .003 14.3 mm ± .07
11
/
16
” (0.687) = .681 ± .003 15.8 mm ± .07
3 /
4
” (0.750) = .744 ± .003 17.3 mm ± .07
13 /
16
” (0.812) = .812 ± .003 20.6 mm ± .07
7 /
8
” (0.875) = .869 ± .003 22.2 mm ± .07
15 /
16
” (0.937) = .932 ± .002 23.7 mm ± .07
1” (1.000) = .992 ± .005 25.2 mm ± .12
1 1 /
4
” (1.250) = 1.244 ± .003 31.6 mm ± .12
METRIC SIZES
10 mm = 9.8 ± .05
Length Tolerances: ± .062” (1.6 mm).
For closer tolerances contact Fast Heat.
The Fast Heat Standard Cartridge heater is
computer designed and specified to include
components that are equal to the wide
variety of applications to which this style of
heater will be subjected.
As with the Hi-Temp Cartridge heater, a
variety of termination styles can be adapted
to this style of heater. When there are
termination requirements other than the
ones illustrated, please contact Fast Heat.
There may be applications where, due to
the wattage requirement, it would be
appropriate to specify a Standard Cartridge
heater but the application dictates that a
Hi-Temp be considered. Such applications
are where distributed wattage is required or
the heater would be subjected to extreme
vibration or impact in operation.
Contact Fast Heat for higher voltage and
amperage ratings, and special diameters
or tolerances.
AVOIDING COMMON HEATER
FAILURE MODES
Use recommended maximum watt
density range to avoid excessive watt
densities which result in the internal
overheating of the heater.
A clean and properly bored hole in rela-
tion to heater diameter is required for
good heat transfer.
Be aware that moisture/contamination
will reduce the life expectancy of a heater.
Consider specifying that either the disc or
lead end or both be sealed, depending
upon the specific conditions to which the
heater is being subjected.
Review lead exit variations and select the
style that best suits your particular
application. Consider such conditions as
contamination, abrasion, flexing and
sharp bending of the leads as they exit
the heater.
It is recommended that watt density be
reduced by 20% for those heaters
subjected to frequent cycling.
To avoid burn-out by operating in open
air, heated length must always be fully
inserted. In addition, an exposed heated
section of the heater may cause a
hazardous condition.
Sheath
End disc
Resistor
coil
ENGLISH EQUIVALENT
.394” = .389” ± .003