Disc Disk Ring Shaped Ceramic PTC Thermistor Stone for Telecom High Voltage

Product Specification

Disc Disk Ring Shaped Ceramic PTC Thermistor Stone for Telecom High Voltage Current Surge Protection

PTC Thermistor Application in Telecommunication Equipment

Central Office Switching Equipment (C.O): analog and digital line cards, POTS, T1/E1 equipment, xDSL modems and splitters, multiplexers, CSU/DSU, servers.
Primary Protection Modules: MDF (main distribution frame) modules, network interface devices (NIC).
Custom Premises Equipment, also known as subscriber terminal equipment (T.E.), IT equipment: Modem, phone sets, fax machines, phone wall outlet (plugs), alarm systems, answering machine, PBX systems, ADSL Splitters, internet appliance, POS terminals.
Access Network hardware, LAN WAN equipment, Powered Ethernet systems, VoIP (voice over IP equipment), integrated voice data (IVD), Set-top box (S.B), etc.
Landline telephones or FAX machines
Telephone interface of STB, VoIP equipment
Any other equipment of communication facility having a phone line interface

PTC Thermistors Telecom Application Features

Compliant with ITU-T K20 K21 K45
–Basic level lightning surges (10/700μs)
–Basic level power Induction (600V,1A,0.2S)
–Power contact criteria A/B (230V,15min.)
Suitable for continuous connection to main voltage 110/230 VAC in tripped (high ohmic) condition.
Round leadless disk thermistor available for combined usage of PTC and primary protection, e.g gas arrestor.
Thermistor disk coated non-coated construction, diameter 5mm to 10mm.
Typical Resistance @25C (R25) 10 ohm, 12 ohm, 18 ohm, 20 ohm, 25 ohm, 50 ohm, 55 ohm.
Matching available with narrow resistance tolerance.
Tight resistance tolerance maintained after switching.
Negligible resistance drift after soldering or switching.

Telecom PTC Thermistor Performances

Rated Zero-power Resistance (R25)
Operating temperature range: 25±2℃, Within the allowable tolerance.

Non-operating Characteristic
Operating temperature range: 40±2℃.
In static air for 30min.
Max. voltage: 60VDC.
Non-operating current.
Energized time: 60min.
(R-R25)/R25≤50%

Over-current operating characteristic
Operating temperature range: 25±2℃,
Max. voltage of power supply: 220Vrms.
Test the time for the current decrease to limited value. See the spec. Table.

Over voltage withstanding (Power line contact)
Voltage of power supply: 250VAC,
Initial current: 3A,
Energized time: 30min .
Restore time in room temperature 4 hours,
then test the R25. ΔR/R25≤20%.

Over current withstanding
Max. voltage of supply: 220VAC,
Initial current: 3A.
ON 60S, OFF 600S ,
Cycle:30 times,
Restore time in room temperature is 4 hours,
then re-test the Rn. ΔR/Rn≤20%.

Surge current withstanding
Current waves: 10/1000μS,
Minimum opening circuit voltage: 1.0kv,
Peak current: 25A,
Interval: 3min,
Cycle:30 times,
Restore time in room temperature is 4 hours,
then re-test the R25. ΔR/R25≤20%.

Induction voltage current withstanding (Only for maximum voltage more than 600V)
Max. voltage of supply: 650VAC,
Initial current: 1.1A,
ON 60S, OFF 600S,
Cycle:10 times,
Restore time in room temperature 4 hours,
then re-test the R25. ΔR/R25≤20%.

Fail Model
I. Voltage of power supply: 250VAC. Initial current: 10Arms,
II. Voltage of power supply: 600VAC. Initial current: 15Arms.
III. Voltage of power supply: 650VAC. Initial current: 10Arms.
Energized time: 30min.

High resistance or open circuit is allowable. Low resistance state or firing is not allowed.

Restore time
The necessary time of a PTC to return to twice of R25. ≤60S.

PTC Thermistor for Telecom Line Card Protection DataPTC Thermistor for Telecom Line Card Protection Data

Note: Standard Resistance @25C (R25) allowable tolerance +/-20%, if not specified.

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