2322 661 93043

2322 661 93043 Datasheet

CATALOGUE NUMBER 2322

Part	Datasheet
2322 661 93043	2322 661 93043 (pdf)

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BCcomponents DATA SHEET Overload protection for telecommunication PTC thermistors Supersedes data of 17th May 1999 File under BCcomponents, BC02 2000 Oct 10 BCcomponents PTC thermistors • Wide resistance range in telecom area to 70 • Fast protection against power contact faults • Withstand high overload currents of up to 10 A • High voltage withstanding capabilities for the larger sized thermistors • Good tracking over a wide temperature range for all matched or binned types • UL1434 approved types available XGPU2 • Excellent stability over extended time • All telecom PTCs are coated with a high temperature silicon lacquer UL94V0 to protect them from any harsh environments and to improve their lifetime. • Main Distribution Frame MDF • Central Office Switching C.O. • Subscriber Terminal Equipment T.E. • Set-top box S.B. . Advanced developments in telephony equipment in recent years have radically altered the protection requirements for both exchange and subscriber equipment. The BC Components range of Positive Temperature Coefficient PTC thermistors includes devices specially designed to provide overcurrent protection. Overload protection for telecommunication PRIMARY PROTECTION OPTIONAL subscriber lines SECONDARY PROTECTION PTC voltage clamp SUBSCRIBER LOOP INTERFACE CIRCUIT SLIC OR TRANSFORMER CCB913 Fig.1 Typical telephone line equipment showing where PTC thermistors can be used for overcurrent protection. 2000 Oct 10 BCcomponents PTC thermistors Overload protection for telecommunication OVERCURRENT PROTECTION OF TELECOMMUNICATION LINES The PTC thermistor must protect the telephone line circuit against overcurrent which may be caused by the following examples: • Surges due to lightning strikes on or near to the line plant. • Short-term induction of alternating voltages from adjacent power lines or railway systems, usually caused when these lines or systems develop faults. • Direct contact between telephone lines and power lines. To provide good protection under such conditions a PTC thermistor is connected in series with each line, usually as secondary protection see Fig.1. However, even with primary line protection usually a gas discharge tube , the PTC thermistor must fulfil severe requirements. Surge pulses of up to 2 kV can occur and in order to withstand short-term power induction the PTC thermistor must withstand high voltages. If the line has primary protection a 220 V to 300 V PTC thermistor is adequate. Without primary protection, however, a 600 V PTC device is necessary. BCcomponents manufacturers a range of PTC thermistors see Table 2 covering both requirements. In the case of direct contact between the telephone line and a power line, the PTC thermistor must withstand very high inrush power at normal mains voltage. Under such conditions, overload currents of up to 10 A on a 230 V mains could occur for up to several hours. To handle this power, the resistance/temperature characteristic of the thermistor must have a very steep slope and the ceramic must be extremely homogeneous.

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BCcomponents

DATA SHEET

Overload protection for telecommunication PTC thermistors

Supersedes data of 17th May 1999 File under BCcomponents, BC02
2000 Oct 10

BCcomponents

PTC thermistors
• Wide resistance range in telecom area to 70
• Fast protection against power contact faults
• Withstand high overload currents of up to 10 A
• High voltage withstanding capabilities for the larger sized thermistors
• Good tracking over a wide temperature range for all matched or binned types
• UL1434 approved types available XGPU2
• Excellent stability over extended time
• All telecom PTCs are coated with a high temperature silicon lacquer UL94V0 to protect them from any harsh environments and to improve their lifetime.
• Main Distribution Frame MDF
• Central Office Switching C.O.
• Subscriber Terminal Equipment

T.E.
• Set-top box S.B. .

Advanced developments in telephony equipment in recent years have radically altered the protection requirements for both exchange and subscriber equipment. The BC Components range of Positive Temperature Coefficient PTC thermistors includes devices specially designed to provide overcurrent protection.

Overload protection for telecommunication

PRIMARY PROTECTION OPTIONAL
subscriber lines

SECONDARY PROTECTION

PTC voltage clamp

SUBSCRIBER LOOP

INTERFACE CIRCUIT SLIC OR

TRANSFORMER

CCB913

Fig.1 Typical telephone line equipment showing where PTC thermistors can be used for overcurrent protection.
2000 Oct 10

BCcomponents

PTC thermistors

Overload protection for telecommunication

OVERCURRENT PROTECTION OF TELECOMMUNICATION LINES

The PTC thermistor must protect the telephone line circuit against overcurrent which may be caused by the following examples:
• Surges due to lightning strikes on or near to the line plant.
• Short-term induction of alternating voltages from adjacent power lines or railway systems, usually caused when these lines or systems develop faults.
• Direct contact between telephone lines and power lines.

To provide good protection under such conditions a PTC thermistor is connected in series with each line, usually as secondary protection see Fig.1. However, even with primary line protection usually a gas discharge tube , the PTC thermistor must fulfil severe requirements.

Surge pulses of up to 2 kV can occur and in order to withstand short-term power induction the PTC thermistor must withstand high voltages. If the line has primary protection a 220 V to 300 V PTC thermistor is adequate. Without primary protection, however, a 600 V PTC device is necessary. BCcomponents manufacturers a range of PTC thermistors see Table 2 covering both requirements.

In the case of direct contact between the telephone line and a power line, the PTC thermistor must withstand very high inrush power at normal mains voltage. Under such conditions, overload currents of up to 10 A on a 230 V
mains could occur for up to several hours. To handle this power, the resistance/temperature characteristic of the thermistor must have a very steep slope and the ceramic must be extremely homogeneous.

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Datasheet ID: 2322 661 93043 521612