Excellent thermal stability
Suitable for use from -65oC to 260oC
Inert to most chemicals and fluid even at high temperature
Suitable for high frequency use
Light weight and compact
Good mechanical strength and flexibility
Resistance to UV radiation and stress cracking
Lower dielectric constant and dissipation factor
Non-toxic and fire proof
Immune to ageing, fungus and water absorption
FREE DESIGN SERVICE FOR PTFE
INSULATED WIRES & CABLES
TECHNICAL ADVISORY SERVICE on wire/cable
design and related areas of electrical engineering is
offered at no charge. Please let us know the statement
of performance and test requirements, rather than material/size
specs. Detailed information on Working Voltage
(AC or DC), current, frequency,Zo,
attenuation,longest inter-connection length,voltage
drop, ambient conditions, (temperature and/or
chemical environment), dimensional and weight
limitations, unusual constraints or hazards,servicing
problems etc. will help in optimum design.
It is often observed that buyers specify
wires or cables that are presently used in PVC or other
lower temperature insulating materials, and require
equivalent sizes -- not just of conductors but also
overall diameters -- in PTFE. This kind of one-to-one
substitution of lower temperature wires is not advisable
for the simple reason of high cost. One should
design the wire for each given application. For
this purpose, as much of the details mentioned in the
previous paragraph, as are available, need to be specified.
With an experienced designer, it is often possible to
substantially reduce the sizes of low-temperature wires
for much the same performance at a marginal increase
in cost, while providing the added bonus of much higher
reliability in the long run.
Any wire consists of materials with two
completely opposite kind of properties: a highly conductive
inside core which is the conductor, and a highly
non-conductive material to cover the conductor that
is the insulation. The insulation provides
protection against voltage and higher voltages
will need higher wall thickness of insulation, keeping
in mind also the physical and mechanical requirements.
On the other hand, the cross-section of conductor is
determined based on the requirements of current (amperes).
Based on the needs of flexibility, maximum working temperature,
and other considerations, one is able to ascertain the
material composition and construction as well as platings
For help in ascertaining the size of
conductor for given current, we refer to a graph showing
Current vs. Temperature Rise Above Ambient.
For example, if 5 amp
current is passed through a 24 AWG conductor, the
temperature rise above ambient will be about 24°C.
If maximum ambient temperature is 50°C, then the maximum
conductor temperature will be 74°C. For reasons
of safety, it is advisable not to go beyond 130°C
for Silver Plated Copper (SPC) and 180°C for Nickel
Plated Copper (NPC) conductors.
This is in the case of a single wire.
For multi-cores, where a number of heat-emitting conductors
are in close proximity of each other, further de-rating
is needed and will depend on the actual conditions.
Voltage dropis another important
consideration, especially when working with low DC voltages,
or when the inter-connection length is long, or there
is heavy in-rush current during start up of heavy loads/motors.
A thumb rule is that 3-5% of voltage drop can be acceptable
under most situations, even though specific cases may
need more stringent control.
Questionnaire for High Voltage Corona Resistant (HVCR) Cable
High Voltage Corona Resistant (HVCR)
wires/ables need to perform under critical conditions.
It is, therefore, necessary to carefully evaluate the
application requirements, before a design is finalized.
When specifying these wires, the designer needs to carefully
differentiate between the actual maximum voltage that
the wire is likely to be exposed to (working voltage
or operating voltage, AC or DC), thetest voltage
on 100% length (proof voltage) and Break Down
Voltage (destructive tests on end-samples).
In our case, it may also be worthwhile to consider the
minimum Break Down Voltage required under the Progressive
In order to offer an optimum design for
HVCR wire/cable, as much of the information as available
from the points listed below, will be helpful:
1. Details of HV cable
presently used, construction (dia, material)
2. Problems with present cable and improvements
4. Actual continuous maximum working voltage
5. Duty Cycle (on-off
time), short-term and long-term basis (1 day vs 1 year)
6. Wave shape (AC frequency,
DC, Pulse etc.)
7. Maximum current
8. Dia and Weight limitations (min due to connectors
and maximum limit)
9. Longest inter-connection length
10. Ambient temperature, maximum
wire surface temperature allowed
12. i) Corona Conditions
ii) Are there sensitive
electronic circuits nearby, sensitive corona signal
interference? (in that case shielding with PTFE or VFG
jackets are advised)
13. Any electromagnetic interference (EMI)
14. Shield required? (shielding
will help to reduce corona effects on nearby circuits)
15. Any specific tests required
on the cable?
16. Our normal capacitance is 100 pF/m.
Please indicate capacitance requirements.